14—
COASTAL ZONE RIPARIAN SYSTEMS

MANAGEMENT AND CONSERVATION CHALLENGES IN AN AREA OF RAPID DEVELOPMENTAL CHANGE

Protection of Riparian Systems in the California Coastal Zone^[1]

John Zentner^[2]

Abstract.—Protection of riparian systems is a major concern in coastal California. The Coastal Plan, written in 1975, advocates riparian protection through watershed management plans. The Coastal Act, passed in 1976, contained strong riparian corridor protection policies but deleted the concept of watershed management. This paper explores past actions of the California Coastal Commission to protect riparian systems and discusses the contradiction between strong riparian protection and relatively weak watershed regulation.

Introduction

Despite the efforts of many federal, state, and local agencies, private organizations, and concerned citizens, riparian vegetation continues to disappear at an alarming rate in California (Beer 1978). Although no separate data are available for coastal areas, subjective observations indicate that this loss also holds true in the state's coastal watersheds.

The California Coastal Commission, a state agency within the Resources Agency, is charged with protecting coastal resources, and is concerned about continued degradation of riparian systems. Through its power to regulate development, the Commission, in conjunction with local government, has the ability to guide much of the growth and change in the coastal zone. This paper discusses the genesis of the Commission, what it has done to protect riparian systems, and what the future may hold.

Background

A Governor's Panel recommended in 1936 that a coastal commission be established. However, it was not until 1969 that the first legislation toward that end was introduced.^[3], ^[4] When the Legislature failed to pass a coastal bill, activists gathered enough signatures to place an initiative on the ballot. The initiative, Proposition 20, passed by a 55.1% margin in November, 1972. Proposition 20 established the predecessor of the Coastal Commission, the California Coastal Zone Conservation Commission (CCZCC). The CCZCC was charged with writing a coastal plan in three years and regulating development in the coastal zone. Under Proposition 20 the coastal zone extended landward to the "highest elevation of the nearest coastal mountain range" except in Los Angeles, Orange, and San Diego Counties where it extended to the highest elevation or 8 km. (5 mi.) inland, whichever was less. However, the permit zone only went about 900 m. (1,000 yds.) inland. Thus the "coastal zone" included most coastal watersheds but CCZCC permit authority over development extended only a relatively short distance inland.

In 1975, the CCZCC adopted the California Coastal Plan and submitted it to the Legislature. In addition to an inventory of coastal resources and policies on coastal planning issues, the Plan contained several provisions on protection and management of riparian systems as follow:

Coastal streams are vital to the natural system of the coast;

[1] Paper presented at the California Riparian Systems Conference. [University of California, Davis, September 17–19, 1981].

[2] John Zentner is Resource Ecologist for the California Coastal Commission, San Francisco, Calif. Opinions expressed by the author do not necessarily reflect views of the California Coastal Commission.

[3] Marsh, Linda. 1978. The California Coastal Commission: Who's minding the shore? South Bay Tribune, Manhattan Beach, Calif. 12 July, 1978.

[4] In 1965, the Legislature created the Bay Conservation and Development Commission (BCDC) to regulate development in San Francisco Bay. BCDC became an important precedent for creation of a coastal commission. See Odell (1972) for a history of BCDC.

coastal streams directly affect the coastal environment;

they are vital to anadromous fish that live in both salt and fresh water;

they collect and transport sand from the watershed to supply coastal beaches;

they are valuable to the aesthetic and recreational enjoyment of coastal waterways; and

they are interrelated with the estuarine systems that in turn are essential to the productivity of the marine environment.

Coastal streams also significantly influence flooding, natural ecosystems, agricultural water supply, and groundwater recharge within the coastal land environment. Watershed areas are thus an ideal focus for developing management techniques to maximize utilization and preservation of natural resources of the coastal zone. (California Coastal Zone Conservation Commission 1975)

These findings linked riparian system protection with watershed management. Thus, basic policy for CCZCC riparian system protection would be establishment of comprehensive watershed management. Policy 22 provided the guidance and detail on development of these plans:

Prepare and implement comprehensive watershed management plans:

a. Procedure for Preparation and Implementation of the Plans. A lead agency at the State level designated by the Legislature (e.g., the Resources Agency, Department of Conservation, or Water Resources Control Board) shall coordinate watershed planning and work closely with affected local governments, other State agencies, and Federal agencies. The coastal agency shall participate in an advisory role in the overall watershed planning program and watershed plans beyond the coastal resource management area.

b. Content and Goals of the Plans. The watershed management plans shall relate upland and shoreline land use management to the protection and restoration of the marine environment; use consistent assumptions, standards, and criteria for determining appropriate future population levels and land uses within each coastal watershed; consider statewide interbasin interests (e.g., true costs of water importation); and otherwise assure that allowable development conforms to the Coastal Plan. The plans shall stress the protection of coastal groundwater resources, streams, wetlands, and estuaries, and shall prevent significant adverse impacts on these resources . . . (ibid .)

Watershed management is used by many state water resource departments for water supply planning. However, these departments have rarely considered themselves land-use planning agencies, and have generally tried to simply manage water supply to meet demand (White 1969). It was partially the failure to resolve the increasingly complex conflicts between riparian and watershed protection and water regulation that led to an outcry for more land-use oriented watershed planning (see Howe 1978; Burke and Heaney 1975).

The Coastal Plan reflected this concern by incorporating resource protection and the concept of limiting growth to the level of available resources. However, the land-use planning aspect of these plans provoked substantial concern among local governments. Opposition to further state control was so great that when the Coastal Plan was modified and adopted by the Legislature as the Coastal Act of 1976, the watershed management policies of the Plan were not included in the Act.

Clearly, including coastal watersheds in the coastal zone makes good sense. Upstream developments affecting downstream areas, especially wetlands, could be regulated and the multitude of different governmental bodies coordinated—but the political effort would be considerable. The amount of land which would have been added to the coastal zone was enormous, especially in the north state. This factor alone made it politically infeasible to include watershed management in the Coastal Act.^[5]

The Act is, however, very protective of the riparian corridor. Section 30236 states:

Channelizations, dams, or other substantial alterations of rivers and streams shall incorporate the best mitigation measures feasible, and be limited to (1) necessary water supply projects, (2) flood control projects where no other method for protecting existing structures in the flood plain is feasible and where such protection is necessary for public safety or to protect existing development, or (3) developments where the primary function

[5] Douglas, Peter. April, 1981. Personal conversation. California Coastal Commission, San Francisco, Calif.

is the improvement of fish and wildlife habitat.

Section 30240 states:

(a) Environmentally sensitive habitat areas shall be protected against any significant disruption of habitat values, and only uses dependent on such resources shall be allowed within such areas.

(b) Development in areas adjacent to environmentally sensitive habitat areas and parks and recreation areas shall be sited and designed to prevent impacts which would significantly degrade such areas, and shall be compatible with the continuance of such habitat areas (California Coastal Act of 1976).

Other portions of the Act established six Regional Commissions, defined development broadly, gave the Commission the power to approve, deny or condition development permits, and directed each local jurisdiction to develop a local coastal plan, which, when certified by the Commission, would give the jurisdiction permit authority over coastal development. In addition, the Act seeks to minimize flood and other hazards and to assure that, in case of policy conflicts, decisions will seek a balance which is most protective of natural resources. The definition of coastal zone also underwent some changes. The coastal zone now extends 4.8 km. (3 mi.) seaward and averages 915 m. (1,000 yds.) inland from the mean high tide line. This distance is reduced in some built-up areas, such as parts of San Francisco, Los Angeles, and San Diego, but can be expanded up to 8 km. (5 mi.) where necessary to protect significant coastal resources.

The remainder of this paper discusses pertinent Commission actions on permits, local coastal plans, and other areas which have affected riparian systems.

Permits Affecting Protection of Riparian Systems

As indicated above, the Commission has permit authority over a wide range of activities within the coastal zone. For this paper, a brief survey was made of permits which were appealed to the state Commission after a regional commission decision, and which were concerned with protection of riparian systems. These are presented below by the issue which seems to characterize each best. Unless otherwise noted, these appeals are referenced by their Commission appeal number.

Development in a Riparian Corridor

The Los Virgenes Municipal Water District sought a permit to expand its handling facility in Monte Nido Valley in the Santa Monica Mountains. The applicant wished to grade and channelize a portion of a small creek to construct a new shop and maintenance building in proximity to the other structures. The Commission approved the permit but required, as a condition of approval, that no grading and channelizing be done in the riparian corridor and that the shop be relocated.

A second major issue which surfaced with this permit concerned impact of the wastewater discharged to Malibu Creek from the facility. The Water District collected data on its discharge for an entire year, and collaborated with the Regional Water Quality Control Board in a report which concluded that the discharge had no effect on algae, fish, or macroinvertebrates in the creek. Based on that report, the Commission concluded that the discharge was not harming the biological productivity of the stream and approved the permit (Appeal 39–80).

The Orange County Flood Control District applied for a permit to remove from a channelized portion of San Juan Creek in Orange County 280,000 cubic yards of sediment deposited by a storm. The Commission aproved the permit on the condition that the flood control district use the excavated material for beach replenishment, thereby avoiding potential shoreline erosion problems. In this case, the Commission made extensive findings showing that removing creek sediments would deplete sand replenishment of downcurrent beaches (Appeal 200–80).

Cumulative Impact of Incremental Developments

A private landowner applied for a permit to divide a four-acre parcel into two parcels for residential development in Cold Creek Canyon in Malibu. Much of the site is either within the Cold Creek Significant Ecological Area (SEA) or the SEA buffer zone as designated in the Commission's Malibu/Santa Monica Mountains Area Plan. The Commission's interpretive guidelines contain policies recognizing the cumulative impacts of new development in Cold Creek Canyon and recommend against new land divisions in the area. The Commission denied the permit, finding that the project would set a precedent by allowing more land divisions in the canyon, thereby severely undercutting the guidelines. The Commission decided that the cumulative impacts of the buildout in the canyon would have significantly degraded the creek's riparian systems (Appeal 360–80).

The Commission has not blocked all development in this area, however. Another applicant was granted a permit for terracing a hillside above Cold Creek for orchard and vineyard planting. The Commission found that this low-intensity use, if properly buffered, was compatible with protection of the biological productivity of the creek (Appeal 53–79).

Setbacks for Development

A private landowner applied for a permit to construct a single-family residence on a narrow

lot in Los Flores Canyon in Los Angeles County. The lot was not wide enough for a 50-ft. setback between the septic tank and the stream. The Commission denied the permit, noting that some riparian vegetation would have been destroyed by the riprap needed to protect the house during moderate floodflows. In addition, the Commission found there was not enough room for an adequate stream buffer (a minimum of 30 m. (100 ft.)) from the house (Appeal 61–80).

Timber Harvesting Along Riparian Corridors

Prior to passage of the Coastal Act, the Masonite Corporation applied for a permit to cut timber on 170 ha. (420 ac.) of land along the Albion River in Mendocino County. The lumber company proposed to leave 30-m. (100-ft.) natural buffers along the edge of the river in accordance with the Forest Practices Act, although the company indicated it would harvest the trees left in the buffer after the rest of the trees had been cut. Several local residents spoke in opposition to the permit, requesting that at least 60- to 90-m. (200- to 300-ft.) buffers be required to protect local salmon spawning grounds and blue heron rookeries. The Commission approved the permit but required 60-m. buffers along the river (Healy 1977).

Under the Coastal Act, the Commission was not given the authority to regulate commercial timber operations larger than 1.2 ha. (3 ac.). The Legislature determined that the Forest Practices Act and the Board of Forestry should have sole jurisdiction over larger operations. However, the Coastal Act directed the Commission to submit to the Board of Forestry a list of forest special treatment areas where logging could adversely affect rivers or streams. The Board later adopted these special treatment areas and certain other changes in forestry practices also suggested by the Commission (Blumenthal 1979).

In another case, after the Act was passed, a private landowner applied for a permit to harvest timber, about five cords per year, on a 1-ha. (2.5-ac.) parcel near the Eel River Delta in Humboldt County. The Department of Fish and Game raised concerns about the permit, fearing it could set a precedent for logging other parcels in that area. The Department, the Commission and Humboldt County had been working extensively with local landowners to develop riparian protection measures for the delta. The Commission denied the permit and made the finding that, in order to fully protect the riparian system, no cutting could be allowed until a detailed, comprehensive management plan for the area could be developed (Appeal 68–81).

Local Coastal Programs

Each city or county with jurisdiction in the coastal zone is required to prepare a Local Coastal Plan (LCP) under the Coastal Act. An LCP is composed of the Land Use Plan (LUP) and zoning ordinances implementing the LUP. The Commission reviews each LCP and decides on its conformity with the Coastal Act. The following section discusses two LCPs submitted by the County of San Mateo and the City of Oceanside.

San Mateo County

The San Mateo County LCP, approved 5 December, 1980, was the first county LCP to be certified by the Commission. As one of the earliest plans, it has often been held up as a model for its resource protection policies. The riparian protection policies are especially strong:

Definition of Riparian Corridors

Define riparian corridors by the "limit of riparian vegetation" (i.e., a line determined by the association of plant and animal species normally found near streams, lakes and other bodies of freshwater: red alder, jaumea, pickleweed, big leaf maple, narrowleaf cattail, arroyo willow, broadleaf cattail, horsetail, creek dogwood, black cottonwood, and box elder). Such a corridor must contain at least a 50% cover of some combination of the plants listed.

Designation of Riparian Corridors

Establish riparian corridors for all perennial and intermittent streams and lakes and other bodies of freshwater in the Coastal Zone. Designate those corridors shown on the Sensitive Habitats Map and any other riparian area meeting the definition of Policy 7.7 as sensitive habitats requiring protection, except for man-made irrigation ponds over 2,500 square feet surface area.

Permitted Uses in Riparian Corridors

a. Within corridors, permit only the following uses: (1) education and research, (2) consumptive uses as provided for in the Fish and Game Code and Title 14 of the California Administrative Code, (3) fish and wildlife management activities, (4) trails and scenic overlooks on public land(s), and (5) necessary water supply projects.

b. When no feasible or practicable alternative exists, permit the following uses: (1) stream dependent aquaculture provided that non-stream dependent facilities locate outside of corridor, (2) flood control projects where no other method for protecting existing structures in the flood plain is feasible and where protection is necessary for public safety or to protect existing development, (3) bridges when supports are not in significant conflict with corridor resources, (4) pipelines, (5) repair or

maintenance of roadways or road crossings, (5) logging operations which are limited to temporary skid trails, stream crossings, roads and landings in accordance with State and County timber harvesting regulations, and (7) agricultural uses, provided no existing riparian vegetation is removed, and no soil is allowed to enter stream channels (San Mateo County 1980).

The plan also contained extensive policies on performance standards in riparian corridors, establishment of buffer zones, and permitted uses and performance standards in buffer zones. These policies form the basis of the County's LCP ordinances and are now being applied to new development in the coastal portion of San Mateo County.

City of Oceanside

Oceanside's LUP was a different situation. On 8 December, 1981, the Commission determined after two public hearings that several sections of the LUP were not in conformity with Coastal Act policies. One of the sections concerned development in the San Luis Rey River system. The Commission staff reported:

The City's LCP proposes the construction of State Highway 76 through the San Luis Rey River Valley. The proposed construction would include the removal of previously deposited spoils banks, grading of valley slopes, removal of approximately 4.4 acres of old growth riparian habitat, and construction of the expressway.

The currently proposed Route 76, as included in the City's LUP presents serious questions as to impacts on the habitat values of the valley. LCP policies to protect the sensitive resources of the river would require the City to:

a. Post signs at appropriate locations noting regulations on littering, offroad vehicles, use of firearms, and leash laws.

b. Encourage the California Department of Fish and Game to actively enforce the Fish and Game Code in the river area.

c. Require property owners to remove debris from their properties when fire or health hazards exist.

d. Monitor future public use of the river area to identify areas of overuse. If such areas are identified, take steps to restrict access commensurate with the carrying capacity of the resources.

e. Encourage CALTRANS to buy and restore the spoil bank on the south side of the river west of I-5 as a first priority. Acquisition of habitat for the endangered plant Dudleyaviscida shall be a second order priority.

f. Continue police and code enforcement against litterers, trespassers, offroad vehicles, and other violators.

The general nature of these policies would not adequately protect the habitat values of the area as is required by the Coastal Act. Major development in the area would disrupt endangered plant/animal species and result in an overall reduction in the resource values of the area.

The San Luis Rey River area, as detailed in the CALTRANS biological Resource Analysis has biological significance in several respects: "As a natural ecosystem with great diversity surrounded by a highly urbanized area; as an important locality for rare and endangered species and utilization by a diverse assemblage of animals. The various plant communities have interrelationships that tend to indicate that the canyon is a single functioning ecosystem."

As the only publicly accessible coastal riparian stream corridor in San Diego County, the area has significant resource value. In testimony before the State Commission, the representative from the State Department of Fish and Game stated: "The systematic destruction of nearly every coastal river valley in Southern California confers added importance to the maintenance of this and the one or two other remaining river valleys where enough differing and contiguous habitats exist to function at an ecosystem level."

The San Luis Rey River, wetlands, and riparian areas are environmentally sensitive habitat as defined in Section 30107.5 of the Coastal Act. The expressway would be located in and/or adjacent to wetland riparian areas and in this location the project would have to be found consistent with Sections (a) and (b) of Section 30240. Section (a), discussed earlier, addresses the appropriate uses in an environmentally sensitive habitat area. Clearly a road is not a resource dependent use. The Commission has previously described and defined resource dependent uses in its certification of the County of Humboldt North Coast Area Land Use Plan. The Commission considered a variety of interpretations of resource dependent:

"(1) Resource dependent uses are those requiring the use of the ecosystem that led the area to be designated as environmentally sensitive habitat; (2) resource dependent uses may depend on one aspect of the total habitat, but that particular aspect must in turn relate to the functioning of the whole or be an integral part of the habitat value of an area; and (3) any use that relies on the existence of a resource that is simply present in the habitat area". In the North Coast Plan, the Commission considered whether timber harvesting and firewood removal in riparian corridors were resource dependent. Timber harvesting was clearly dependent upon trees as an available, renewable resource. However, locating a road in a riparian corridor is not dependent on any of the renewable/non-renewable resources of the San Luis Rey River area and therefore conflicts with Coastal Act policies regarding sensitive habitat.

As currently proposed, the project has adverse impacts on the environmentally sensitive habitat of the valley (noise, water pollution, air pollution, destruction of sensitive habitat, loss of endangered plants, isolation of remaining riparian areas from coastal sage scrub hillside, etc.) and would therefore require extensive mitigation. Such required mitigation measures have not been adequately identified by either the City or Caltrans. City policies would require transplantation of the endangered Dudleyaviscida , and Caltrans proposed to remove the spoils banks as mitigation for the removal of 4.4 acres of old growth riparian habitat, but other project impacts have not been addressed. In the absence of detailed mitigation proposals, the project would conflict with recommendations by the State Department of Fish and Game and the U.S. Fish and Wildlife Service that the whole river area should be afforded protection due to the uniqueness of its ecosystem.

In order to protect the integrity of the river and maintain the functional capacity of related habitat areas, the Commission finds that the policies proposed by the City of Oceanside are not in conformity with the policies of Chapter 3 of the Coastal Act (California Coastal Commission 1981a).

This LUP was an important test case for the riparian protection policies of the Coastal Act. The Commission subsequently approved the remainder of the City's LUP leaving the San Luis Rey River portion uncertified. This meant the Commission retains permit jurisdiction until the plan is revised and approved.

Special Guidelines

The Commission adopts interpretive guidelines primarily for use in reviewing coastal permit applications. These help interpret the Coastal Act and explain Commission precedent to insure consistency. The Statewide Interpretive Guideline for Wetlands and Other Wet Environmentally Sensitive Habitat Areas include considerable guidance on riparian habitat protection (California Coastal Commission 1981b).

Statewide Interpretive Guideline for Wetlands and Other Wet Environmentally Sensitive Habitat Areas

The wetland guideline was adopted February 4, 1981 after almost two years of public hearings and numerous revisions. It represents a major effort on the part of the Commission to protect wet environmentally-sensitive habitat areas. Although the guideline focuses primarily on wetlands, it also addresses riparian areas: defining rivers and streams, riparian habitat, permittable development in streams and rivers, and criteria for establishing buffer areas. Because buffer width can vary depending on the circumstances, the guideline requires the following factors be considered in an analysis: 1) biological significance of adjacent lands; 2) sensitivity of species to disturbance; 3) susceptibility of parcel to erosion; 4) use of natural topographic features to locate development; 5) use of existing cultural features to locate buffer zones; 6) lot configuration and location of existing development; and (7) the type and scale of development proposed.

The guideline has proven very useful in permit analysis. It provides solid, technical criteria for regulating development. This type of guidance is necessry to implement a complex statute, particularly when political and economic pressure are present.

Conclusions

This report demonstrates that the Coastal Commission has had considerable experience in protecting riparian systems in the coastal zone. Although not discussed as part of this report, other agencies, particularly the Department of Fish and Game, deserve a great deal of credit for this achievement. Their assistance and technical recommendations to the Commission have been greatly appreciated.

However, several gaps exist in this protection network. First, only riparian corridors in the coastal zone are protected. The riparian zone is part of a system which includes upstream headwaters and the surrounding watershed. Degradation of upstream areas is eventually reflected in downstream changes, ultimately in the coastal zone. Most of the watersheds are outside the

coastal zone; without good upstream protection it is somewhat futile to discuss long-term downstream regulation.

Second, watershed concerns such as erosion are complex and difficult to address issues. Development within a stream or river corridor is relatively easy to regulate because the resource is identifiable and the impacts direct. Sedimentation from an upslope development, for example, is difficult to trace; its impact difficult to assess. To complicate matters further, effects of sediment in the riparian corridor may be adverse or beneficial (beach replenishment, for example, versus silting of spawning beds).

In addition, under the Coastal Act, removal of vegetation for agricultural purposes is not considered development—and therefore not regulated by the Commission. This problem is especially apparent in Santa Barbara and Ventura Counties where conversion of native vegetation to avocado production is drastically increasing the rate of sedimentation in coastal streams. Local governments are attempting to grapple with this problem with varying degrees of success.

Finally, the Commission itself has a very heavy workload and is subject to some political pressure. In accordance with state law, the regional commissions, which absorbed a large amount of work, were dissolved on 1 July, 1981. The Commission meets only eight days each month. Members of the public, seeking to speak to issues on the Commission's agenda are often limited to two to three minutes per item due to the large number of speakers. Given this situation, it could become easy to ignore the complexities of each issue and forego substantive discussions. This would jeopardize resource protection policies of the Coastal Act and the clear precedents the Commission has set to date.

Recommendations

It would be easy to simply recommend that watershed plans be prepared for all areas. The political pressure against such a measure would be overwhelming. It is more fashionable presently to talk about decreasing the role of government in our lives. On the other hand, who else will be concerned with an entire watershed and the riparian and instream systems it feeds? A neo-classical economic approach, such as advocated by Ostrom and Ostrom (1972), would place each watershed within the control of one user group, on the theory that someone who owns a resource will take better care of it than many individuals who have no incentive to safeguard the resource.

Instead, I would suggest an alternative. All jurisdictions within the state, whether in the coastal zone or not are required to prepare land use plans. I would recommend requiring them, through statute, to include a watershed element in such a plan. This could also include membership in a watershed planning program as suggested in the Coastal Plan.

Second, education on watershed and riparian issues needs to be greatly expanded. The effort which went into disseminating information on the importance of wetlands was enormous and began over a decade ago; issues of riparian protection are only beginning to become a subject of debate.

Riparian system protection in the coastal zone is a reality. The California Coastal Act assures protection of our rivers and streams within the coastal zone. However, that protection does not extend outside the coastal zone, nor does it adequately protect watersheds inside or out of the coastal zone. These limitations should be changed to insure adequate protection of riparian systems throughout California.

Literature Cited

Beer, Jack. 1978. Identifying habitat types and disappearance rates. p. 38–54. In : Proceedings of the instream use seminar. 178 p. California Department of Water Resources, Sacramento.

Blumenthal, Robert. 1979. Vegetation management report. California Coastal Commission special report. 68 p. California Coastal Commission, San Francisco, Calif.

Burke, Roy, and James Heaney. 1975. Collective decision making in water resources planning. 238 p. Lexington Books, New York, New York.

California Coastal Zone Conservation Commission. 1975. California Coastal Plan. December, 1975. State Documents and Publications Branch, Sacramento.

California Coastal Commission. 1981a. Staff report to the California Coastal Commission from Bob Brown, Chief Planner, and Michael Buck, Staff Analyst. 44 p. California Coastal Commission, San Francisco.

California Coastal Commission. 1981b. Statewide interpretive guideline for wetlands and other wet environmentally sensitive habitat areas. 46 p. California Coastal Commission, San Francisco.

Healy, R.G. 1977. An economic interpretation of the Californi Coastal Commissions. 270 p. Conservation Foundation, Washington, D.C.

Howe, C.W. 1977. Comparative analysis and critique of the institutional framework for water resources planning and management. 106 p. Office of Water Research and Technology, Washington, D.C.

Odell, Rice. 1972. The saving of San Francisco Bay. 115 p. Conservation Foundation, Washington, D.C.

Ostrom, Vincent, and Elinor Ostrom. 1972. Legal and political conditions of water resource development. Land Economics 48(1):1–14.

San Mateo County. 1980. Local coastal plan. 368 p. County of San Mateo, San Mateo, California.

White, Gilbert. 1969. Strategies of American water management. 288 p. University of Michigan Press, Ann Arbor, Michigan.

Plant Species Composition and Life form Spectra of Tidal Streambanks and Adjacent Riparian Woodlands Along the Lower Sacramento River^[1]

John W. Willoughby and William Davilla^[2]

Abstract.—Flora and life forms of the tidal streambank plant community along the Sacramento River near Collinsville, Solano County, California are compared to those of adjacent plant communities. The tidal streambank flora has a significantly smaller non-native component than the floras of adjacent riparian woodland and annual grassland communities. All three communities have developed in historically disturbed habitats. Rhizomatous herbs represent the predominant life form of the tidal streambank community. In contrast, the riparian woodland community has a much lower percentage of rhizomatous herbs and higher percentages of annual and woody species. Reasons for these differences are discussed.

Introduction

Plants growing in the intertidal zones of river systems are subjected to rather rigorous growing conditions. Regular, periodic inundation by fresh to brackish waters makes establishment and subsequent growth of vascular plants difficult. Relatively few plant taxa are capable of coping with such conditions. Some plant taxa, however, are totally restricted to intertidal areas of major river systems and are often rare (Ferren and Schuyler 1980).

In some river tidal areas, water salinity (and resultant soil salinity) may be a limiting factor to plant establishment and survival. This is especially true of riverine systems near oceans and bays where substantial volumes of salt water mix with the fresh water of the rivers.

This study examines the life form strategies of the vascular plants in the intertidal zone along the lower Sacramento River (herein referred to as the "tidal streambank" community). This community is compared to the adjacent riparian woodland community. Floristic composition and richness of these two communities and the adjacent annual grassland community are compared.

Study Area

The study area is located on the northern banks of the lower Sacramento River east of Collinsville, Solano County, California. The river at this point becomes part of the Sacramento/San Joaquin estuary. Study plots were located at the mouth of Marshall Cut, extending a distance of 1.0 km. east and 0.3 km. west of the cut along the bank of the Sacramento River. Riverbanks in this area were artificially created by levee construction designed to reclaim natural tidal marshland between 1900 and 1940 (Atwater etal . 1979). Tidal streambank and riparian woodland vegetation has developed on the levees during the short period since their construction. Inland of the levees, artificial landfill has resulted in displacement of former natural tidal marshlands. These recent fill areas now support a disturbed cover of annual grassland composed almost entirely of introduced plant species. An artificially flooded marsh behind the levee east of Marshall Cut is presently managed as a duck club. The flora and elevational zonation of vascular plants in this marsh/grassland mosaic have been considered elsewhere (BioSystems Analysis, Inc. 1979).

Methods

Tidal streambank, riparian woodland, and annual grassland plant communities were subjectively delineated using primarily physiognomic criteria. The riparian woodland community was identified by the presence of tree and shrub strata. In the few cases where these strata were poorly developed or lacking, this community was identified by the presence of herbaceous species

[1] Paper presented at the California Riparian Systems Conference. [University of California, Davis, September 17–19, 1981].

[2] John W. Willoughby is Botanist/Range Conservationist, USDI Bureau of Land Management, Sacramento, Calif. William Davilla is Senior Botanist, BioSystems Analysis, Inc., San Francisco, Calif.

commonly associated with the riparian woodland community.

The criteria used to identify the tidal streambank community were: 1) its position between the river and the riparian woodland community; 2) the absence (with two exceptions) of woody species; and 3) the presence of species which flower in late summer to early fall. Upper limits of the tidal streambank community correspond roughly to the upper level of the levee banks inundated by maximum high tides.

The annual grassland community was recognized by its inland location, the absence of woody species, and the predominance of annual grass and forb species which flower in the spring.

A complete species list was compiled for each of these three plant communities. The life forms of each species were determined using available literature (e.g., Munz 1959; Mason 1957; Robbins etal . 1951) and field observations. Five life forms were recognized: annual, perennial herb (including biennials), rhizomatous perennial herb (including herbs spreading by stolons and creeping root systems), shrub, and tree. In a few cases a species may function as either an annual or a perennial. These facultative species were scored under both the annual and perennial herb categories. Suffrutescent (only obscurely or very modestly woody) plants were scored as perennial herbs. Woody plants which exhibit both a tree and shrub habit (e.g., Salix spp.) were scored as either shrubs or trees based on the principal life form exhibited in the study area.

Results and Discussion

The major environmental variables controlling the distribution of vascular plants in tidal marshes of the northern San Francisco Bay estuary are elevation and water salinity (Atwater and Hedel 1976). Elevation of marsh surfaces relative to tide levels determines the soil moisture content and frequency, duration, and depth of submergence, whereas the salinity of the water flooding a marsh determines the soil salinity (ibid .). Water salinity is an important influence in the regional distribution of tidal marsh plants; high soil salinity causes many plants to disappear toward San Francisco Bay, resulting in tidal marsh communities composed of only 13 or 14 native plant species (Atwater etal . 1979). Where water salinities are rather low, as in the Sacramento/San Joaquin Delta, tidal marsh communities are more diverse, containing some 40 plant species, most of which are relatively salt-intolerant—largely the same species that occur in freshwater marshes in California (ibid .).

Water salinities in the vicinity of the study area vary both seasonally and annually in response to the amount of freshwater flow from the river systems. Figure 1 shows the variation in mean monthly water salinities at Collinsville. Judging from the salinity data for Collinsville, water salinity is probably not a major limiting factor for plants in the intertidal zone there. Except in unusual circumstances (such as the drought of 1976–77) the water in this area varies from essentially fresh to only slightly brackish. Because of the regular flushing action of the tides and the rapid runoff from riverbanks at low tides, soil-salt concentrations resulting from evaporation would not be expected to be significantly higher than the water salinity of the river. That soil salinities are not high in the intertidal zone of this area can be inferred from the absence of salt-tolerant plants such as Distichlisspicata and Frankenia grandifolia from the upper reaches of the intertidal zone.

Figure 1.
Mean monthly water salinities (in parts per thousand) of the
Sacramento River at Collinsville, California. The bottom line
averages monthly means over the period 1967–80. The top
line represents monthly means for 1977, the year with the
highest salinities on record (from USDI Bureau of
Reclamation, Tracy Field Division).

The major ecological factor influencing the distribution of plants in the intertidal zone of the study area is considered to be elevation with respect to tide levels. Tidal heights (in decimeters) at the confluence of the Sacramento and San Joaquin Rivers (near the study area) are as follows (based on data in Simpson etal . 1968; definitions from Atwater etal . 1979):

10.1—mean higher high water (average height of the higher of the daily high tides);
–3.4—mean lower low water (average height of the lower of the daily low tides);
18.3—estimated maximum high water;
–7.6—estimated minimum low water.

Plants tolerant of relatively long periods of submergence (e.g., Scirpusacutus , S .

californicus , and Typha spp.) occupy lower sites along the river (below mean higher high water), whereas species less tolerant of long submergence (e.g., Carex barbarae , Hydrocotyleverticillata var. triradiata , and Lythrumcalifornicum ) occur at higher elevations in the intertidal zone (at or above mean higher high water).

A complete list of the vascular plants of the three plant communities considered in this study (tidal streambank, riparian woodland, and annual grassland) is found in Appendix A.

A tabulation of the flora of the three communities is given in table 1. The riparian woodland community contains the largest number of species (78) followed by the tidal streambank (49) and annual grassland (38) communities. The annual grassland community is included here primarily to illustrate the highly disturbed nature of the site. The low total number of species present (38) and the very high percentage of introduced species (82%) attests to its disturbed condition.

The riparian woodland community also supports a large non-native component (29 species). Over 30% of species are introduced plants, the majority of which also occur in the adjacent annual grassland community.

The tidal streambank community supports the smallest number of introduced species (8), only 16% of the total species. This figure compares favorably with the proportion of introduced species in the California flora as a whole, but is low compared to most California cismontane areas (table 2). Only the floras of Mount Diablo and Mount Hamilton Range have similar non-native components. The published floras of these two areas, however, are almost 40 years old; the percentages of introduced taxa present in both areas are almost certainly higher today.

The percentage of introduced species present in the tidal streambank community is especially low given the disturbed nature of the site. As previously indicated, this community has developed since the construction of levees between 1900 and 1940. The riparian woodland and annual grassland communities have also developed during this same time period. Their floras, however, exhibit a significantly higher percentage of introduced plant species. Annuals comprise a large percentage of the introduced species in the annual grassland (59%) and riparian woodland (42%) communities. An additional 32% of the introduced species of the annual grassland and 35% of those in the riparian woodland are perennial, non-rhizomatous herbs. Both of these life forms, especially the annuals, appear to be at a competitive disadvantage in the tidal streambank environment. Fifty-eight percent of the tidal streambank flora consists of rhizomatous herbs (fig. 2). Of the 29 species of rhizomatous herbs present in the tidal streambank community, only three (10%) are introduced.

It thus appears that the primary reason for the low number of introduced species in the tidal streambank community (relative to the other two communities) is the restricted capability of introduced plants (most of which are annuals or non-rhizomatous perennials) to establish under conditions of periodic or prolonged inundation. This fact is further emphasized by the relative paucity of introduced species in areas within the intertidal zone which have been more recently disturbed by riprapping. Although cover and density in riprapped areas are far lower than on undisturbed levees, the species which are found in these areas are predominantly native.

The life form spectra of the tidal streambank and riparian woodland plant communities (fig. 2) highlight several differences between these two communities. Almost 25% of the species present in riparian woodland are woody species, as opposed to 4% (2 species) of the total species found in the tidal streambank community. Twentyfive percent of the riparian woodland species are annuals—62% are introduced—while 14% (6 species) of the intertidal flora are annuals—43%

Figure 2.
Life form spectra of the tidal streambank and riparian woodland plant communities. Height of the bars corresonds to the percentage
of the total species in the community represented by each of the five life forms. A—annual; PH—perennial herb (including biennials);
RH—rhizomatous perennial herb (including herbs spreading by stolons and creeping root systems); S— shrub; and T—tree.

are introduced. The percentage contribution of perennial, non-rhizomatous herbs to the floras of both communities is almost identical, 24% for the tidal streambank community and 25% for the riparian woodland (the absolute species numbers are 10 and 21, respectively). Perhaps the most significant difference between these two communities is the much greater proportion of rhizomatous herbs in the flora of the tidal streambank plant community (58% of the total species compared with 28% for riparian woodland community).

Certain life forms enjoy an apparent competitive advantage in the tidal streambank community. Perennials account for 86% of the total flora, suggesting that one major limiting factor is the difficulty of seedling establishment under the ebb and flow of tidal waters. This would put annuals at a distinct disadvantage. The annual strategy may also be a handicap in another way: in an azonal community where water is not limiting, dry season dormancy is not only unnecessary but is probably detrimental. Rhizomatous species are more successful than non-rhizomatous species, a fact which may be at least partially explained by the greater ability of the former to apomictically spread once established. Even the two woody species present in the intertidal zone, Salix lasiolepis and the introduced Rubusdiscolor , are capable of extensive vegetative reproduction. Thus 63% of the tidal streambank flora is capable of vegetative reproduction.

In terms of floristic composition and life form spectra, the tidal streambank community in this rather disturbed area is remarkably similar to that of other, less disturbed areas in the Sacramento/San Joaquin estuary (compare the species list for Browns Island in Knight 1980). However, the plant cover and density of the tidal streambank community of the study area are certainly lower relative to less disturbed examples of this community elsewhere, although this fact is yet to be quantitatively documented.

Many of the species of the tidal streambank community (e.g., Typhalatifolia , Scirpusacutus ) have very wide distributions and occur in several types of moist to wet habitats. However, a few of the tidal streambank species in the study area exhibit restricted distributions and occupy only the intertidal habitat. Asterchilensis var. lentus and Lilaeopsis masonii are both recognized as rare and endangered by the California Native Plant Society (Smith etal . 1980). Both of these taxa and a third, Grindeliapaludosa , formerly considered rare and endangered, are entirely restricted to intertidal areas in the Sacramento/San Joaquin estuary. Although these plants are not particularly rare in the habitats in which they occur, their continued existence may be threatened by human alterations of their narrow habitats. The practice of riprapping streambanks results in a significant loss of habitat; potential increases in water salinity of the estuary as a result of

proposed future freshwater diversions may have deleterious effects on these plants.

Summary

The flora of the tidal streambank plant community along the lower Sacramento River near Collinsville is markedly different from the floras of adjacent riparian woodland and annual grassland communities. Non-native plant components of the latter two communities are significantly larger than that of the tidal streambank community, although all three communities have developed within the last 40 to 80 years. The proportion of introduced plants in the tidal streambank community is low even in areas more recently disturbed by riprapping. Introduced species, most of which are annuals or non-rhizomatous perennials, appear to be at a competitive disadvantage in the tidal streambank zone.

The life form spectra of tidal streambank and riparian woodland communities illustrate several significant differences between these two communities. Rhizomatous herbs are the most important life form of the tidal streambank community, apparently because of their facility to spread under conditions unfavorable to seedling establishment. Annuals are at a competitive disadvantage probably for the same reason, and also due to the handicap resulting from dry season dormancy in an azonal habitat where water is not limiting. In contrast, the riparian woodland community has a much lower proportion of rhizomatous herbs and higher percentages of annual and woody species.

In terms of floristic composition and life form spectra, the tidal streambank community that has developed in this disturbed area is similar to that of other, less disturbed areas. Three rare plant species occur in the intertidal zone of the study area, and are restricted in distribution to the intertidal zone of the Sacramento/San Joaquin estuary. Although not currently rare where they occur, they appear to be very narrowly adapted to this habitat. Additional human alterations of their habitat may threaten their continued existence.

Literature Cited

Atwater, B.F., S.G. Conard, J.N. Dowden, C.W. Hedel, R.L. MacDonald, and W. Savage. 1979. History, landforms, and vegetation of the estuary's marshes. p. 347–385. In : T.J. Conomos (ed.). San Francisco Bay: the urbanized estuary. Pacific Division, American Assoc. Adv. Sci., San Francisco, California.

Atwater, B.F., and C.W. Hedel. 1976. Distribution of seed plants with respect to tide levels and water salinity in the natural tidal marshes of the northern San Francisco Bay estuary, California. USDI Geological Survey Open File Report 76–389.

BioSystems Analysis, Inc. 1979. Potential for mitigation of salt marsh losses and associated adverse impacts on salt marsh harvest mice at the proposed Montezuma powerplant site. Unpublished report prepared for Pacific Gas and Electric Co. 51 p.

Bowerman, M.L. 1944. The flowering plants and ferns of Mount Diablo, California. 290 p. Gillick Press, Berkeley, California.

Ferren, W.R., Jr., and A.E. Schuyler. 1980. Intertidal vascular plants of river systems near Philadelphia. Proc. Acad. Nat. Sciences of Philadelphia 132:86–120.

Howell, J.T. 1970. Marin flora. Second edition with supplement. 366 p. University of California Press, Berkeley.

Howell, J.T. 1972. A statistical estimate of Munz' Supplement to a California Flora. Wasmann Journal of Biology 30:93–96.

Knight, W. 1980. The story of Browns Island. Four Seasons 6(1):3–10.

Mall, R.E. 1969. Soil-water salt relationships of waterfowl food plants in the Suisun Marsh of California. California Department of Fish and Game, Wildlife Bulletin No. 1. 59 p.

Mason, H.L. 1957. A flora of the marshes of California. 878 p. University of California Press, Berkeley.

Mueller-Dombois, D., and H. Ellenberg. 1974. Aims and methods of vegetation ecology. 547 p. Wiley and Sons, New York, New York.

Munz, P.A., and D.D. Keck. 1959. A California flora. 1681 p. University of California Press, Berkeley.

Robbins, W.W., M.K. Bellue, and W.S. Bell 1951. Weeds of California (1970 reprint). 547 p. Documents and Publications, State of California, Sacramento.

Sharsmith, H.K. 1945. Flora of the Mount Hamilton Range of California. Amer. Midl. Nat. 34:289–367.

Simpson Stratta and Associates, and K.H. Baruth. 1968. Suisun Soil Conservation District Master Plan Study II. Suisun Soil Conservation District, Dixon, California.

Smith, G.L., and A.M. Noldenke. 1960. A statistical report on A California Flora. Leaflets of Western Botany 9:117–123.

Smith, J.P. Jr., R.J. Cole, and J.O. Sawyer, Jr. 1980. Inventory of rare and endangered vascular plants of California (in collaboration with W.R. Powell). Special Publ. No. 1 (second edition). 115 p. California Native Plant Society, Berkeley.

Thomas, J.H. 1961. Flora of the Santa Cruz Mountains of California. 434 p. Stanford University Press, Stanford, California.

Sediment Control Criteria for an Urbanizing Area in San Diego County, California^[1]

James S. Jenks, Thomas C. MacDonald, and James P. McGrath^[2]

Abstract.—Studies were conducted to develop criteria and methodologies to mitigate the effects of urbanization on sedimentation processes at North City West in San Diego County. A sediment control plan was developed and adopted to mitigate these effects using on-site erosion controls and detention basins.

Introduction

The urbanization of undeveloped land can cause many environmental, social, and legal problems, many of which are associated with changes in the hydrologic and sedimentation regimes of the area. The California Coastal Commission has been concerned with these problems in the coastal zone and, in the case of the Los Penasquitos Lagoon-North City West (NCW) area (San Diego County), has been instrumental in developing policies and solutions to urbanization problems. The following paragraphs present the background leading to these policies and solutions and describe the Los Penasquitos Lagoon and NCW areas.

Background

When the voters in California passed Proposition 20 in 1972, they established the Coastal Commission for the purpose of planning for the preservation of the coast of California for all the people of the state. The Commission made recommendations for long-term management of the coastline which are embodied in the California Coastal Plan. Recognizing that changes in coastal streams and wetlands are closely associated with changes in the watershed, the plan recommended that watershed management be required for coastal watersheds.

In 1976, when the Legislature established a permanent agency and body of legislation to carry out the goals of the Coastal Plan, it did not require watershed management plans, although Section 30231 of the Coastal Act did provide a general policy that runoff should be regulated and managed.

In the legislative mapping of the coastal zone, particularly in urbanizing areas, the coastal zone boundaries are generally too narrow to allow meaningful watershed management. However, there are exceptions to this in various areas along the coast. In Southern California, there are three major exceptions: the Santa Monica Mountains, where the coastal zone boundary included virtually the entire coastal watershed of the proposed national recreation area; the Aliso and Wood Canyon areas in southern Orange County, where the coastal zone included much of the proposed Laguna Greenbelt; and the Los Penasquitos Lagoon area in the northern part of the city of San Diego, where a significant portion of the watershed tributary to the lagoon is within the coastal zone.

The need for protecting the State-owned wetland was clearly evident in Los Penasquitos Lagoon. However, even there, political reality tempered the concept of watershed management. Only the floors and slopes of Carmel Valley, Penasquitos Canyon, and Lopez Canyon were included in the coastal zone. Carroll Canyon and much of the undeveloped area proposed to be developed in the city's NCW community were excluded. In exchange for this mapping of the coastal boundaries, the City of San Diego (and through its influence, the League of Cities), tempered its position on pending bills. In addition, the planning director pledged the city's cooperation in mitigating potential adverse effects of the highly controversial NCW development.

The Coastal Commission's experience in San Diego County under Proposition 20 had clearly revealed that urban development resulted in increased rates of sedimentation. The causes and mechanisms of these problems were less clear, so the Commission authorized a "special study" of the lagoon and watershed by a geologist/hydrologist. The resulting study, by Karen Prestegaard

[1] Paper presented at the California Riparian Systems Conference. [University of California, Davis, Sept. 17–19, 1981].

[2] James S. Jenks and Thomas C. MacDonald are Principal Engineers with Leeds, Hill and Jewett, Inc., San Francisco, Calif. James P. McGrath is Coastal Analyst, California Coastal Commission, San Francisco, Calif.

provided some of the answers. The study recommended: 1) preservation of the natural areas of sediment storage (largely the undeveloped floodplains); and 2) mitigation of the increased storm flows associated with urbanization to prevent scour of sediment from the stream-beds and banks and increased downstream movement of sediment associated with such scour and increased flow.

The city of San Diego and local developers began further studies to implement these recommendations in the detailed planning of individual developments. The most successful effort was, ironically, in NCW. One of the major developers of the area authorized the detailed hydrologic analyses needed to carry out the recommendations of the Prestegaard study. The resulting study by Leeds, Hill and Jewett, Inc.^[3] , was successful enough to be incorporated as an element of the city's Local Coastal Program (LCP).

Los Penasquitos Lagoon

Los Penasquitos Lagoon is a coastal lagoon about 1.6 km. (1 mi.) long and 0.8 km. (0.5 mi.) wide, located in San Diego County. It consists of flat marshlands laced with deep tidal channels and interspersed with occasional tidal and salt flats (California Department Fish and Game 1974). The size of the lagoon is being slowly reduced by inflows of sediment from the Los Penasquitos watershed. Reports indicate that before 1888, the lagoon was continuously connected to the ocean. Railroad and highway construction through the lagoon in the 1920s drastically changed drainage patterns in the lagoon area and led to intermittent blockages of the mouth of the lagoon.

Removal of the beach and cobble littoral drift material that collects at the outlet of the lagoon to the ocean was first tried in 1966 to reestablish tidal flushing. It was believed that improved tidal flows would encourage the restoration of a healthy marine fauna to the lagoon. However, maintenance of the outlet to the ocean has been sporadic since 1966 and generally not successful.

One important factor involved in keeping the mouth of the lagoon clear is the volume of water which passes through the opening during one tide cycle. This volume is called the tidal prism. Accumulations of sediment in the lagoon reduce the tidal prism, which reduces the natural sediment-removing mechanism of the lagoon. It has been noted that in recent years there has been a net accumulation of sediment in the upstream areas of the lagoon.

North City West

In 1975 the North City West Community plan^[4] was prepared by the City of San Diego for a new community to be located near the north city limits. The boundaries of NCW encompass about 1,740 ha. (4,300 ac.), most of which are tributary to Los Penasquitos Lagoon. The community will consist of a variety of housing types, commercial developments, and public facilities, including recreational areas and open spaces. The areas associated with each type of development are presented in table 1.

The estimated total number of dwelling units planned for NCW is 13,970, sufficient to house a population of about 40,000. The community will have an employment center and town center. It will also have small commercial centers scattered throughout the area which will contain a variety of light industry, commercial establishments, and offices to serve the needs of future residents and to provide employment opportunities. Open space areas consist of parks, floodplains, areas of hazardous geology, and slopes greater than 25%. The NCW community will be developed by various developers and property owners.

As described in the Community Plan,^[4] the NCW area will be developed as nine separate units. More than one of these units may be under development at any one time.

Technical Principles and Criteria for Sediment Control

Technical Principles

Development of NCW will have significant impacts on the sedimentation regime of the area which, if not regulated, could increase the rate of sediment accumulation in Los Penasquitos Lagoon.

[3] Leeds, Hill and Jewett, Inc. 1980. North City West drainage study. Report to Pardee Construction Company, San Francisco, Calif. 44 p.

[4] City of San Diego, 1975. North City West Community Plan. 147 p. San Diego, Calif.

Currently most of the NCW area is undeveloped, with the predominant vegetative cover being annual grasses and open brush. Some of the land is used for agricultural and grazing purposes. Soils in the area are fine-grained and cohesionless and are predominately in hydrologic soil group D, which has a very low infiltration rate. This soil-type, along with the minimal vegetative cover and, in some areas, overgrazing, makes the area subject to the erosive forces of rainfall and runoff. This situation is aggravated by point discharges into the unprotected drainage channels in the western part of NCW of urban runoff from areas on the west side of Interstate Highway 5. During the recent wet years, these point discharges have, in at least one place, eroded a huge gully and transported several thousand cubic yards of sediment downstream, some of which has been deposited in the lagoon.

When NCW is developed, the potential for sediment runoff will initially increase when vegetative cover, which tends to hold the soil in place, is removed by grading operations. Sediment runoff during this period must be controlled to avoid clogging the downstream channels and lagoon with sediment.

After NCW is developed, sediment production from the area will be less than currently occurs. Sediment production will decrease as a result of open space and developed areas being protected by roof tops, streets, lawns, and other erosionresistant groundcovers.

Also after development, rainfall over much of the area will be collected in non-erosive roadbeds, gutters, and storm drains and conveyed to the stream channels, thereby avoiding concentrated flows over sediment-producing areas. Other sediment control devices in NCW, such as berms, downdrains, etc., will protect against local sedimentation damages to other portions of the development.

Although sediment production from NCW will be less after the area is developed and the vegetation is well established, the amount and rate of runoff will increase. The amount of runoff will increase because there will be less infiltration loss in the impervious areas of the development. The rate of runoff will increase because runoff will be collected and conveyed to the downstream channels in a more rapid manner than occurs naturally. Because of this more rapid drainage, runoff from larger areas during the most intense periods of precipitation will be more nearly simultaneous than normal.

The increased volumes and rates of rainfallrunoff and the reduced amount of sediment production after NCW is developed will, if not controlled, have long-term effects on the sediment regime of channels downstream from the development. The increased rates and volumes of runoff will have a greater capacity to transport sediment than the flows that now occur and the watershed will not supply as much sediment to the flows. Thus, if drainage controls are not provided, erosion of the bed and banks of stream channels can be expected downstream of points where runoff is discharged from NCW.

From the foregoing, it is apparent that both short-term and long-term drainage control plans are needed for NCW to protect against sediment damages to downstream areas.

Drainage Control Criteria

During the construction period, the most effective control plan for a proposed development is to provide on-site controls to reduce the amount of sediment that would otherwise run off the construction slopes. Such controls include vegetating bare slopes, constructing low berms and drains, and other short-term measures.

Reduction of sediment erosion by means of protecting land surfaces can effectively eliminate sediment runoff from many areas. However, it may not be possible to protect all areas or the protection used may not be completely effective at all times. In these cases, it will be necessary to provide additional backup controls. These backup controls have the function of collecting the sediment that does run off before it can cause any downstream damage.

For the long-term, drainage control facilities must be provided that regulate outflows from the development such that the ability of the outflow to erode sediment from the downstream channels is reduced. For a constant rate of flow, the amount of sediment that can be transported is directly proportional to the duration or the volume of flow. However, in most cases it is not practical to try to reduce the volume of stormwater runoff. The sediment transport capacity of the flow increases disproportionately faster than increasing flow rate. Thus, to protect against erosion of downstream channels, it is more important to regulate the rate of runoff.

It is also important that the facilities that provide the long-term control of sedimentation problems allow passage of sediment from the developed watershed. Sediment from the developed watershed will satisfy part of the sediment transport capacity of the downstream flows. To the extent that outflows from an area contain less sediment than the flow's capacity to transport sediment, the flow will try to make up the sediment deficiency by eroding the bed and banks of the downstream channel. Thus, it is important that sediment runoff from the watershed pass through the control facilities and into the downstream channels.

In implementing the recommendation that increased storm flows be mitigated, a number of difficult technical issues had to be resolved. First, the design storm event to be the basis of analyses needed to be selected. Second, methods for estimating and comparing runoff had to be established.

The field work done for the Prestegaard study indicated that the storm event with a recurrence interval of from one to two years did not appear to be the channel-forming event for this Mediterranean-type climate. Also, five-year storm flows are not substantially greater than the two-year flows. However, storms in 1978 and 1979–80 had an approximate 10-year recurrence frequency and indicated that significant channelforming processes do occur with such storms. Thus, the 10-year storm was selected as the design storm of the analyses. Subsequent analyses showed that the controls developed to regulate runoff from a 10-year event also effectively attenuated runoff from the 25-year storm event—further strengthening arguments for use of the 10-year storm as an analytical base.

The "Rational Formula" for estimating rainfall-runoff is commonly used for subdivision drainage design in the county. This formula estimates the peak rate of rainfall-runoff as the product of the watershed area, rainfall intensity, and an empirical rainfall-runoff coefficient. In general this formula tends to overestimate flow rates. If controls are to be provided to regulate flow rates to natural levels for the purpose of sediment control, that purpose may be defeated by analytical tools that overestimate flow rates. An overestimation of flows from undeveloped lands, if used as a criterion for design of control facilities, would lead to a strategy that did not sufficiently attenuate flows in the developed condition—and thus, failure of the mitigation strategy.

A methodology was developed by Leeds, Hill and Jewett, Inc., for analyzing rainfall-runoff from the 1,740± ha. (4,300± ac.) of land tributary to Los Penasquitos Lagoon to be occupied by NCW. This methodology, which utilizes the US Army Corps of Engineers (CE) HEC-1 computer program, provides accurate estimates of runoff hydrographs from relatively small drainage areas for both developed and undeveloped land-use conditions. The methodology and its verification are described below.

North City West Sediment Control Plan

Methodology

Several methods to control stormwater runoff from developed areas were investigated, and detention basins were found to be the most effective. These detention basins can also be used, on a temporary basis, to protect against potential erosion during construction when slopes will be bare.

Preparation of an effective drainage control plan utilizing detention basins requires determination of stormwater runoff characteristics for existing and future land-use conditions. Estimates of peak runoff under existing conditions are needed to establish the level of regulation that should be provided. Estimates of increases in runoff under future developed conditions are needed to locate and determine the size of detention basin facilities that would regulate future flows to less than those that would occur under existing conditions.

The CE's HEC-1 computer program was used to analyze stormwater runoff. This program is capable of generating estimated runoff hydrographs from precipitation using very small time intervals in the hydrograph calculation. Because the drainage areas used in the analyses are generally small, and therefore have short times of concentration, a method of analysis that uses even smaller time intervals in the hydrograph calculation is necessary to accurately estimate peak discharges. The HEC-1 program provides a cost-effective method of obtaining these estimates.

The HEC-1 program estimates the amount and rate of rainfall-runoff based on the drainage area size, land use, types of soils, intensity of precipitation, and antecedent moisture conditions. These characteristics can be estimated from soil, groundcover, and topographic maps, photographs of the study area, and information gathered during field inspections. Precipitation intensities and antecedent moisture conditions can usually be obtained from local agencies.

During the initial construction period detention basins can be fitted with a temporary riser so that they function as both sediment traps and as detention basins. Once development is complete and slopes are stabilized by vegetation, the temporary riser can be removed. After the riser is removed, the basin outlet would be at the low point of the basin floor such that much of the subsequent inflow of sediment can pass through the basin and into the downstream channel. As previously noted, allowing sediment to pass through the basin will minimize the tendency of the downstream channel to degrade due to a reduction of sediment inflow. Temporary desilting basins can be provided to protect those areas that do not have a downstream detention basin. Use of both desilting basins and modified detention basins during the construction period is considered a backup to the primary on-site controls of vegetation and avoidance of grading during the runoff season.

Verification

The reliability of the methodology used to estimate runoff characteristics of developed and undeveloped areas was verified by calculating runoff from the drainage areas of Pomerado and Beeler creeks, for which actual precipitation and runoff data are available, and by comparing the measured and calculated runoff hydrographs. These creeks are tributary to Los Penasquitos Lagoon and are about 8 km. (5 mi.) east of the NCW area. Stream gauge measurements on these two creeks are available for a short period of record, so the choice of past storms that can be studied is limited.

A storm which occurred on 4 December 1972, was selected for verification. This was an isolated storm which produced fairly uniform and equal amounts of rainfall over both drainage areas. The drainage areas were divided into urbanized and nonurbanized subareas. The Pomerado Creek area is 10.6 sq. km. (4.1 sq. mi.) in size, of which about 15% is urbanized by medium-density residential housing. About 1.6 km. (1 mi.) of the creek channel is concrete-lined. Beeler Creek drainage area is 14.2 sq. km. (5.5 sq. mi.) in size and, except for a very small development, not urbanized.

The measured precipitation data from nearby rain gauging stations along with hydrologic characteristics of the subareas, estimated from soil and topographic maps and aerial photographs, were used in the HEC-1 computer program. The runoff hydrographs from each of the subareas were calculated, routed through the stream channels, and then combined to obtain the total runoff hydrograph from the drainage areas of the two creeks. These hydrographs were then compared with measured flow rates as shown in figure 1. This comparison indicates that the methodology produced reasonable estimates of runoff from Pomerado and Beeler Creek drainage areas and can be used to produce reasonable estimates of runoff for both urbanized and undeveloped areas.

Figure 1.
Calculated and measured discharge for December 4, 1972 storm.

North City West Analyses

Following verification of the methodology, hydrologic characteristics of each drainage subarea in NCW (fig. 2) were determined and are presented in table 2. Future conditions were estimated using the NCW Community Plan.^[4]

Precipitation intensities having recurrence frequencies of 10 and 25 years were used in the analyses for sizing detention basins and analyzing their performance. Peak rates of discharge were computed at the potential basin sites shown in figure 2 for existing and ultimate land-use conditions for the two storm events. These peak discharge rates are presented in table 3 for selected locations.

Alternative basin locations, sizes, and outlet works were then examined to develop a plan which would meet Coastal Commission requirements. It was found that a minimum of three detention basins are needed to meet the requirements but that several alternative combinations of basin locations could be used. Regulated peak outflow rates for one of the alternative plans are presented in table 3.

Hydrographs of stormwater runoff for the 10-year storm under existing and ultimate land-use conditions with and without detention basins are shown in figure 3 for the location where Carmel Creek flows into Los Penasquitos Lagoon. The peak discharge at this location is 554 cubic feet per second (cfs) under existing conditions, 917 cfs under future conditions without detention basins, and 539 cfs with detention basins for the alternative plan that provides detention basins at locations E, R, and H.

In addition to providing for regulation of stormwater runoff under ultimate land-use conditions, the plan requires on-site controls during the interim construction period. These controls provide that no grading be done during the fivemonth period from October 5 to March 15 of each year. It further provides for planting of exposed construction slopes before November 1 of each year to minimize erosion during the rainy winter season. Although this program should be adequate, the plan also provides backup controls by fitting the detention basins with risers during the interim construction period so that they can act as sediment traps.

Figure 2.
North City West drainage areas and detention basin sites.

Figure 3.
Discharges from NCW in Carmel Creek at
Los Penasquitos Lagoon-10-year storm.

Conclusion

The concept of watershed management through stormwater management used in NCW poses great potential for urbanized areas where development goals include minimizing increases in downstream flooding, preserving natural riparian corridors, and/or controlling sediment movement. Although the side canyons of the watershed will be substantially altered through urbanization, the main stem of the stream will be preserved and managed in a state similar to its natural condition. Thus, sediment transport capabilities of the channel will be maintained, although sediment production from the watershed will decrease somewhat after development activities are completed.

The stream's main stem will be capable of maintaining riparian vegetation because flows will not be channelized and stream-bed erosion will be controlled through regulation of runoff rates.

The issues of long-term maintenance of stormwater detention basins, and to a lesser extent, the questions of liability, are unresolved at the present time. To date, the costs and liabilities of a drainage program which incorporates detention basins have not been compared to those of a conventional drainage system. Thus, it is unclear whether overall costs and liabilities will be higher, lower, or comparable to such facilities. However, the advantages to the riparian system are clear.

The drainage studies for NCW and the resulting drainage control plan were accepted by the City of San Diego and submitted as an element of its LCP. The City is also requiring, as part of the environmental impact report process, implementation of these controls in other developments as an element of subdivision design. Thus, developers can integrate these controls into their initial designs, rather than adding them on late in the development planning process when the LCP is reviewed by the Coastal Commission.

Literature Cited

California Department of Fish and Game. 1974. Natural resources of Los Penasquitos Lagoon. California Department of Fish and Game, Sacramento, Calif. 75 p.

Prestegaard, Karen A. No date. Stream and lagoon channels of the Los Penasquitos watershed, California, with an evaluation of possible effects of proposed urbanization. Coastal Commission Special Studies Series, San Francisco, Calif. 75 p.

Management of Riparian Vegetation in the Northcoast Region of California's Coastal Zone^[1]

Dan Ray, Wayne Woodroof, and R. Chad Roberts^[2]

Abstract.—Riparian vegetation has important habitat and economic values. The Coastal Act requires protection of both of these sets of values. Local coastal plans have attempted to resolve this policy conflict by protecting riparian corridors and habitat patches. Protection of large areas of riparian vegetation by land-use regulation has proven difficult.

Introduction

Northwestern California riparian systems include a complex of biological and economic resources seldom surpassed in richness. Riparian systems provide nesting and foraging areas for a diverse wildlife fauna, protect water quality essential to anadromous fisheries, hold substantial commercial timber, and affect floodwaters and sediment movement in ways essential to local agriculture. State and local policies encourage protection of all of these values—a policy mandate requiring government officials to balance competing goals. Developing policies which can be implemented and are technically sound and politically acceptable is a difficult task.

Riparian Systems in the Northcoast Region

The northcoast region of California's coastal zone includes the seaward portions of Del Norte, Humboldt, and Mendocino counties. The coastal zone's inland boundary, established by the Coastal Act of 1976, is typically 914 m. (1,000 yd.) inland from the mean high tide. The boundary runs inland in four large bulges to include significant estuarine, habitat, and recreational areas at Lakes Earl and Talawa in the Smith River delta; Freshwater, Stone, and Big lagoons near Redwood National Park; the Eel River delta, and the Ten Mile estuary and dunes complex in Mendocino County. The largest of these bulges, the Eel River delta, extends inland almost 8 km. (5 mi.) above the river's estuary and up to 18 km. (11 mi.) from Pacific Ocean beaches.

Riparian systems within the northcoast region of the coastal zone are located along most minor streams and all of the major rivers. Their vegetation is characterized by an overstory typically dominated by red alder (Alnusrubra ), Sitka spruce (Piceasitchensis ), and redwood (Sequoia sempervirens ). Black cottonwood (Populus trichocarpa ) is commonly dominant on the floodplains of the Mad and Eel rivers. Pacific wax-myrtle (Myrica californica ), bigleaf maple (Acermacrophyllum ), California-laurel (Umbellulariacalifornica ) and Pacific red elder (Sambucuscallicarpa ) are also common trees and shrubs in mature riparian areas. Willows (Salix spp.) are typical pioneers in disturbed areas. In mature associations, these species are joined by vines, epiphytes, and other herbaceous and woody plants to form a diverse, vertically stratified plant community. For a more complete description of riparian flora, see Roberts etal . (1977) or Proctor etal . (1980).

Wildlife populations in northcoast riparian areas have not been thoroughly surveyed, but lists from comparable areas in inland forests (Marcot 1979; Thomas 1979), coastal Oregon and Washington (Proctor etal . 1980), and other sources (Harris 1973; Monroe 1974) suggest that up to 140 species of birds and 37 species of mammals utilize northcoast riparian forests at some time during the year. Many of these species (wading birds such as egrets, cavity nesters, and some raptors, warblers, and mammalian predators) depend upon mature riparian forest for some portion of their nesting or feeding habitat requirements. The importance of riparian forests may be increased in the northcoast region due to the relatively poor habitat status of upland redwood forest (Leipzig 1972; Harris 1973).

Riparian forests on smaller coastal streams also protect water quality by shading stream

[1] Paper presented at the California Riparian Systems Conference. [University of California, Davis, September 17–19, 1981].

[2] Dan Ray and Wayne Woodroof are Coastal Analysts, North Coast District, California Coastal Commission, Eureka, Calif. R. Chad Roberts is Environmental Analyst, Oscar Larson and Associates, Eureka, Calif.

channels and intercepting and filtering runoff from adjacent uplands. This water quality protection is critical in maintaining aquatic species, including anadromous fish, in coastal rivers and streams (Thompson etal . 1972).

Riparian zones in the northcoast also hold a number of economically important resources. Redwood, Sitka spruce, and red alder are important to local timber processors as sources of lumber, plywood, wood chips, and pulp. With the advent of biofuel-thermoelectric power plants, other riparian species such as black cottonwood may become economically important. Beyond the standing timber value, riparian zones are preferred sites for long-term timber production because of their soil quality and the beneficial effects of periodic flooding. For example, annual growth of commercial redwoods in riparian zones of the Big, Albion, and Navarro rivers of Mendocino County is from 1.2 to 1.4 times that of adjacent upland forest sites (USDA Forest Service 1965). Agricultural uses also benefit from productive riparian soils. Flood-borne sediment deposition on the alluvial valleys of the Garcia, Eel, Mad, and Smith rivers has created highly productive soils more than 1.8 m. (6 ft.) deep. These bottomland soils are up to twice as productive as other local farmlands on diked wetlands or upland terraces (McLaughlin and Harradine 1965). Agricultural land owners also use riparian vegetation as a source of firewood for domestic use.

Use of riparian land in the northcoast region has been dominated by the exploitation of these economic resources at the expense of fish and wildlife habitats. Riparian forests were typically among the first used for commercial timber harvest because of the very high lumber volumes they held and the easy access to rivers and estuaries they offered. Level streambeds were modified to allow construction of cordoroy roads or narrow-gauge railroads used to transport sawlogs. Large expanses of Sitka spruce/black cottonwood forest were cleared for agricultural use. An estimated 6,900 ha. (17,000 ac.) of riparian forest were converted to grazing land in the coastal zone of Humboldt and Del Norte counties. The major floods of 1955 and 1964 caused substantial damage to forested riparian lands on the Smith, Klamath, and Eel rivers. Subsequent construction of flood control projects on the Smith River and at Redwood Creek caused additional losses of riparian vegetation.

Existing northcoast riparian forests are a remnant of this history of development. Relatively large riparian areas remain along Elk Creek and the Klamath River in Del Norte County and the Eel River in Humboldt County. Cutover riparian forests in many small forested watersheds and commercial timberlands along the Ten Mile, Big, Albion, and Navarro rivers in Mendocino County have gone through succession to progressively more diverse second growth forests with high habitat values. Riparian woodland patches can still be found scattered in narrow bands along most streams and in unused portions of farms or residential areas.

Coastal Commission Policy for Management of Riparian Systems

The Coastal Act of 1976 (Public Resources Code 30000 etseq .) created the California Coastal Commission and six regional commissions and charged them with regulating development to protect coastal resources. The Act requires local governments to prepare local coastal plans implementing these policies and authorizes the regional coastal commissions to review local plans and regulate development within the coastal zone until local coastal plans are approved. The Act grants the Commission power to regulate most development affecting riparian systems. The Act does not authorize the Commission to regulate logging operations under timber harvest plans approved by the State Board of Forestry. Instead, the Act empowers the Commission to designate unique coastal resource sites as "special treatment areas" within which timber harvests are carefully regulated under the California Forest Practices Act. Coastal Act policies require protection of sensitive habitat areas and commercial forest lands and encouragement of coastal agriculture. Section 30240(a) of the Coastal Act states: "Environmentally sensitive habitat areas shall be protected against any significant disruption of habitat values, and only uses dependent on such resources shall be allowed within such areas."

Sections 30241 and 30242 require that: "the maximum amount of prime agricultural land shall be maintained in agricultural production to assure the protection of the areas' agricultural economy"; and ". . . lands suitable for agricultural use shall not be converted to non-agricultural uses unless (1) continued or renewed agricultural use is not feasible, or (2) such conversion would preserve prime agricultural land or concentrate development . . . . Any such permitted conversion shall be compatible with continued agricultural use on surrounding lands."

Section 30243 provides that: "long term productivity of soils and timberlands shall be protected and conversions of coastal commercial timberlands in units of commercial size to other uses or their division into units of non-commercial size shall be limited to providing for necessary timber processing and related facilities."

These policies express desirable objectives for state and local action but their application in specific areas may lead to conflicts. Purchase of extensive areas along the Big River in Mendocino County was proposed by the USDI Fish and Wildlife Service (FWS) in 1979 to assure protection of its sensitive estuarine and riparian systems. However, the purchase would convert commercial timberlands to non-commercial use. Installation of riprap or other devices along eroding Eel River banks is essential to the protection of prime agricultural lands, yet the bank

protection would impede the natural erosion and accretion processes that have been essential to the maintenance of Eel River riparian systems.

Local farmers assert that Coastal Act policies provide priority to the agricultural economy and so should permit clearing of riparian vegetation for pasturelands. The California Department of Fish and Game (DFG) argues that the same policies require riparian systems be protected against even removal of domestic firewood. Industrial foresters believe the Coastal Act policies permit conversion of deciduous hardwood vegetation to commercial conifers.

Anticipating such conflicts among Coastal Act policies, the Legislature found in Section 30007.5 of the Act that: ". . . such conflicts should be resolved in a manner which on balance is the most protective of significant coastal resources . . . broader policies which, for example, serve to concentrate development in close proximity to urban and employment centers may be more protective overall than specific wildlife habitat and other similar resource policies."

Based upon this guide, northcoast region staff biologists have turned to conservation ecology theory to formulate policies which identify and protect significant resources of the region's riparian systems.

Conservation Ecology

In the past decade, ecologists have gained insights relating to conservation problems generated when development occurs in or adjacent to relatively undisturbed natural systems. An important work on this subject is that of Pickett and Thompson (1978), which builds upon the theoretical base formed in MacArthur and Wilson (1967). Pickett and Thompson began with concepts from island biogeography, broadened them to include habitat islands in seas of different habitat, and applied the results to conservation issues.

Their basic conceptual conclusion is that if a particular area of undisturbed habitat is reduced in size, the effect is qualitatively like that upon "land-bridge" islands (especially if the "connections" to other, similar habitat patches are severed). The remnant habitat islands are "supersaturated" with species, a phenomenon due to a predictable relationship between island areas and species richness. Reducing the habitat area always leads to a reduction in the number of species that a habitat patch will support; this is an empirical result, verified many times. After developing this point, the authors made several recommendations for habitat conservation. Habitat patches should be large, undisturbed, more-or-less round, and either close to or connected to other, similar patches. In addition, the ecology of the patch should be taken into consideration, including such factors as within-patch successional processes, "patch longevity," and patch replacement rate.

Wilcox (1980) developed these arguments further. By focusing on "insular ecology" Wilcox pointed out that habitat patches should be as large as possible. Since any "habitat" has fewer species than a larger, nearby habitat area (an empirical result), the larger the island, the fewer the missing species. Species typically added with greater patch size are the less common species which are usually the management target. Wilcox presented a technique for calculating species number reductions, given a reduction in patch size. That technical discussion is beyond the scope of this report, but the conclusion drawn is that the greater the habitat area reduction, the greater the magnitude of species lost, and the faster their rate of disappearance.

The relationship between habitat patch area and species diversity has been studied by other investigators. Galli etal . (1976) studied bird species diversity in New Jersey forest islands surrounded by other habitat. Thirty islands were studied ranging in size from 0.008 to 24.3 ha. (0.02 to 60 ac.). Bird species diversity increased in the predicted fashion, and the significant variable was shown to be island area. Until a minimum size threshold was crossed, only "edge" species were present. As the area increased further, "interior" bird species were added, though they tended to be present at low densities. A follow-up study in New Jersey by Forman etal . (1976) concluded that diversity continued to increase with patch size up to the 40 ha. (100 ac.) point. In fact, Forman et al. concluded that the highest bird species diversity would not be reached until areas in excess of 40 ha. were sampled.

Forman etal . (ibid .) also concluded: a) over half of all species encountered were "minimum-area" species, found in larger patches; b) larger patches contained more species than an equal areas of smaller patches; c) most of the increase in diversity in patches larger than about 2.8 ha. (7.0 ac.) was due to insectivorous species; and d) large mammal-eating birds were only present on the larger patches. As management considerations, these authors recommended that patches be as large as possible, and that many smaller "stepping-stone" islands be maintained.

The relationship between body size and geographic range size was discussed by Schoener (1968). He showed that, in general, larger birds required larger territories. Apparently the relative densities of the kinds of food eaten by large (especially predatory) birds decrease as bird body weights increases. This is apparently why such species as Pileated Woodpeckers and Buteo hawks have large territories and, conversely, why there are relatively few of these birds (disregarding the basic question of distribution of their required habitats). Schoener's empirical result dovetails with the field results of Forman et al. (1976), adding credence to the recommendation for large habitat patches.

Further, Gates and Gysel (1978) found that forest edge-nesting bird species were more subject to both predation and cowbird parasitism than interior-nesting species. Forest edges acted as a guide to both predators and cowbirds; nesting success increased in proportion to the distance of the nest from the forest edge. There may be a minimally acceptable patch size which ensures availability of enough area for edge-nesting species to avoid nest losses from predators and cowbird parasitism.

Based upon this analysis, we believe that a premium value should be placed on large expanses of undisturbed riparian vegetation. Such large, undisturbed areas will fulfill "minimum-area" requirements of those large and/or uncommon species which require conditions in patch interiors. A second priority should be for smaller areas of undisturbed riparian vegetation in preference to larger areas of disturbed vegetation. These "stepping-stone island" patches can answer the needs of some smaller "interior" species; if population densities randomly fluctuate to low levels, they can help dispersing individuals recolonize larger patches. Finally, retention of some riparian vegetation along all watercourses is essential. While a narrow strip is not in itself satisfactory habitat, it can help in dispersal, and adds minor foraging area for species in nearby, larger patches.

Policies for Riparian Management

North Coast District local coastal plans being prepared by local governments or already approved by the Coastal Commission generally include riparian vegetation management policies consistent with these recommendations. Where commercial timber use is planned for riparian areas, the conflict between timber production and habitat protection has been resolved through the forest practices rules for special treatment areas. The rules provide protection for many components of riparian systems. Riparian vegetation management policies and their applications in typical riparian systems within the region are discussed below.

Riparian Management on Small Coastal Streams

The northcoast region includes about 240 small coastal streams and their tributaries. Typically, these streams drain watersheds from 1.6 to 6.4 km. (1 to 4 mi.) inland from the coastal zone and would be considered first- and second-order streams under Strahler's (1964) stream ordering rules. Their channels are usually contained within well-defined gorges cutting through the coastal terrace. Riparian vegetation is best developed and most diverse immediately adjacent to the stream channel, although Sitka spruce, redwood, or red alder may extend from riparian zones to adjacent uplands in an undifferentiated forest overstory. Wildlife populations include most typical riparian passerines, but raptors, wading birds, and other avian components of larger riparian systems are absent. Cutthroat (Salmoclarkii ) and steelhead (S . gairdneri ) trout and silver salmon (Oncorhynchuskisutch ) are common spawners within the streams and their tributaries (Humboldt County Planning Department 1978). Most riparian systems have been altered by timber harvest or fire, but many have gone through succession to relatively diverse second-growth forests.

Local coastal plans propose delineation of riparian corridors by assigning fixed distances from stream channels. For example, Humboldt County's southcoast area plan states:

Riparian corridors on all perennial and intermittent streams shall be, at a minimum, the larger of the following: (i) 100 feet, measured as the horizontal distance from the stream transition line on both sides; (ii) 50 feet plus four times the average percent of slope, measured as a slope distance from the stream transition line on both sides; (iii) where necessary, the width of riparian corridors may be expanded to include significant areas of riparian vegetation adjacent to the corridor, slides, and areas with visible evidence of slope instability, not to exceed 200 feet. (Humboldt County Planning Department 1981a)

Identification of riparian areas by vegetation analysis has not been proposed in any local coastal plan in the region because of the similarity of riparian and upland forest vegetation along these streams. Local agencies usually lack personnel trained in the vegetation identification and sampling techniques needed to differentiate riparian and upland systems based on hydrophytic understory components. In addition, the fixed distance riparian corridors proposed in these local coastal plans are familiar to most local residents and public officials because of their use in state and federal forest practices standards.

Uses in riparian corridors are usually limited to minor facilities and resource production, such as timber harvest, under standards designed to protect tree canopies and minimize erosion. Humboldt County's southcoast area plan provides that:

New development within riparian corridors shall be permitted when there is no less environmentally damaging feasible alternative, where the best mitigation measures feasible have been provided, and shall be limited to the following uses: (a) Timber management activities, provided that heavy equipment shall be excluded from the riparian corridor and where feasible, at least fifty percent of the existing tree canopy shall be left standing; (b) Timber harvests smaller than three acres of merchantable timber 18 inches

DBH or greater and non-commercial removal of trees for firewood provided that timber harvest practices shall be consistent with those permitted under the forest practices rules for stream protection zones in Coastal Commission special treatment areas. Where feasible, unmerchantable hardwoods and shrubs should be protected from permanent damage; (c) Maintenance of flood control and drainage channels; (d) Wells in rural areas; (e) Road and bridge replacement or construction, provided that the length of the road within the riparian corridor shall be minimized, where feasible, by rights of way which cross streams at right angles and do not parallel streams within the riparian corridor; (f) Removal of trees for disease control, or public safety purposes. Mitigation measures for development within riparian corridors shall, at a minimum, include replanting disturbed areas with riparian vegetation, retaining snags within the riparian corridor unless felling is required by CAL-OSHA regulation, and retaining live trees with visible evidence of current use as nesting sites by hawks, owls, eagles, osprey, herons, or egrets. (ibid .)

The riparian corridors protected by these policies can maintain habitats which provide "bridges" for wildlife movement between larger stepping stones and riparian islands. Protecting vegetation adjacent to streams can help protect water quality essential to anadromous fisheries. Because of the size of the areas protected and because some activities, such as logging under an approved timber harvest plan, are not regulated by these policies, such policies cannot be relied upon to protect all the riparian components necessary to maximize species diversity.

Policies to protect riparian corridors have met little resistance from landowners and local governments within the area. Most landowners can identify the fixed-distance corridor on their parcels and locate sites outside the corridor which are suitable for development. Local government officials can relate the protection of riparian corridors to local goals of protecting anadromous fisheries and domestic water quality, and so find them politically acceptable

Riparian Management in Remnant Vegetation Patches

Many local coastal programs propose protection of larger patches of riparian vegetation which may be located outside designated corridor areas. These patches are typically undisturbed old-growth forests with a diverse riparian flora and a vertically stratified physiognomy. Wildlife diversity within them may be limited because of their size or location adjacent to other developed uses. They play only a minor role in water quality or anadromous fisheries protection because they are typically located on broad alluvial plains and may be separated from the stream channel by other development. Many of these areas are located in state or federal parklands. Protection of these riparian areas is typically provided by public agencies which manage them.

Protecting similar patches on private lands has proven more difficult. The affected areas may be relatively large (2–10 ha.) and may seem unrelated to public goals for protecting fisheries or water quality. Consequently local officials have been reluctant to regulate such activities as timber harvests or conversion to agricultural use which may affect the habitat value of the area.

A patch of riparian vegetation at Redwood Creek in Humboldt County, of approximately 10 ha. (25 ac.), is typical of these sites (fig. 1). It includes a dense Sitka spruce/red alder stand which is the last remnant of Redwood Creek's old growth riparian forest. It has had little use as agricultural land and remained unharvested when adjacent riparian areas were converted to pasture. The Redwood Creek flood control project separated the site from the creek and provided access to it along the project's levees. Half of the patch is within Redwood National Park. Approximately 5 ha. (12 ac.) in its eastern half are owned by a local cattleman as part of a larger ranch.

Figure 1.
Remnant patches of riparian vegetation, Redwood
Creek, Humboldt County, California.

The local coastal plan (Humboldt County Planning Department 1980a) designated the area for agricultural use and only proposed protection of vegetation within the 30.5 m. (100-ft.) riparian corridor. The owner had no plans to develop or convert the remainder of the site, but resisted land-use policies which required its protection for habitat use. The regional commission did not approve the plan, but stated that it would ap-

prove a revised plan which designated the site for natural resources use and limited new development on it to habitat management and tree removal for firewood purposes under certain conditions. The protection plan for the site recommended by the regional commission will probably be accepted by the landowner and the local government because of the parcel's isolation and its relatively small size. By permitting firewood harvesting, traditional woodlot uses of the stand were maintained, providing some economic return to the property owner.

Patches of riparian vegetation such as this site can provide the stepping stones to connect larger habitat islands. The areas themselves provide habitat for wading birds and cavity nesters which are not common inhabitants of the narrower riparian corridors along small coastal streams. These patches are probably not large enough to accommodate minimum area species such as large raptors or to sustain sufficient numbers of individuals to maintain healthy breeding populations of many smaller riparian species. Those species which depend on such specific conditions as dense canopies or dead or dying wood in snags or on the forest floor may be displaced in the future if firewood harvesting reduces these habitat components. Nonetheless, both types of birds could use the area for resting or foraging while traveling between larger riparian areas.

Management of Large Riparian Systems

Preparing local coastal plans for large riparian systems—the habitat islands for ripariandependent species—has proven to be one of the most difficult tasks facing local governments and the Coastal Commission.

Protecting these riparian areas is particularly troublesome because of the need to maintain the areas in a virtually undisturbed state in order to retain unique habitat components such as dense canopies or dead and down trees. While state and federal wildlife refuges, parks, conservation areas, and wilderness areas provide large blocks of relatively undisturbed wetland, upland forest, or montane vegetation, there are no comparable publicly-owned riparian reserves within the coastal zone in the northcoast region. Protecting these areas will require either public purchase or extensive regulation of substantial amounts of private land. Public purchase is unpopular because of agency financial constraints, effects on local tax bases, and resentment over the already large public land holdings in the region. Local governments are generally unwilling to adopt the strict regulations necessary to protect these areas because the regulations may affect landowners who are frequently representatives of important segments of the local economy.

Constitutional issues (including questions of taking land without compensation) have not been extensively litigated in cases involving riparian vegetation, and most local governments are hesitant to expose themselves to potential legal and financial liabilities. Finally, because most data on riparian system values are from areas other than the northcoast and are not well understood by the general public, local support for protecting large riparian systems is limited.

Three areas provide examples of the problems presented to local governments and the Coastal Commission in managing these large riparian systems.

Elk Creek, Del Norte County

Elk Creek is located immediately northeast of Crescent City, and has a drainage basin covering approximately 1,670 ha. (4,120 ac.). It originates in the upland forests of Jedediah Smith Redwoods State Park and flows into the Crescent City harbor.

Approximately half of the watershed and almost all of the private lands within the Elk Creek basin, are within the coastal zone. About 225 ha. (550 ac.) of the coastal zone portion of the watershed are forested riparian zones, characterized by Sitka spruce, redwood, western hemlock (Tsugaheterophylla ), red alder, and Pacific wax-myrtle (fig. 2). These forests meet freshwater marshes along the creek in an ecotone dominated by willows, Douglas spirea (Spiraeadouglasii ), and twinberry (Lonicerainvolucrata ). Wildlife within the area includes such riparian-dependent species as Red-shouldered Hawk (Buteolineatus ), Snowy Egret (Leucophoyx thula), and Great Blue Heron (Ardea herodias ) (Del Norte Planning Department 1980). The area has been logged, and approximately 15% of its forested lands has been converted to pastureland. Major portions of its basin, including many riparian areas, have been subdivided to parcels of 2 to 8 ha. (5 to 20 ac.) for rural residential use. However, soil moisture has permitted succession of both second-growth forests and abandoned fields to well-developed riparian vegetation. With the extensive clearing of

Figure 2.
Riparian vegetation on Elk Creek, Del Norte County, California.

riparian vegetation along Smith River and at Earl and Talawa lakes, Elk Creek is the principal alluvial riparian system remaining in Del Norte County.

The local coastal plan designated riparian zones in the Elk Creek drainage for a mix of agricultural general, timberland, and woodlot uses.^[5] Those portions of the riparian areas which are frequently flooded were identified as wetlands. The plan included the following policies affecting riparian systems in the Elk Creek watershed:

(1) The filling, dredging or diking of any portion of the Elk Creek wetlands shall be prohibited except where necessary for flood control purposes; or when such activity enhances the biological productivity of the marshland; or when compatible with other policies of the coastal program and a specific finding is made which cites that policy;
(2) A buffer strip shall be maintained in natural conditions around the Elk Creek wetlands;
(3) No permanent structures shall be constructed within the identified portions of the Elk Creek wetlands including any delineated buffer zone;
(4) New development adjacent to the Elk Creek wetlands shall not result in adverse levels or additional sediment, runoff, noise, wastewater or other disturbances;
(5) Snags shall be maintained within the Elk Creek wetland for their value to wildlife;
(6) Riparian vegetation along the course of Elk Creek and its branch streams shall be maintained for their qualities of wildlife habitat and stream buffer zones;
(7) Vegetation removal in the Elk Creek wetland shall be limited to that necessary to maintain the free flow of the drainage courses;
(8) The County should encourage and support educational programs in schools, park programs and community organizations which seek to increase public awareness and understanding of sensitive habitats and the need for their protection. (ibid .)

The regional commission did not approve the land-use plan because of the designation of sensitive riparian lands for potential development, even though at low densities, and the absence of a specifically defined buffer zone. The regional commission stated that it would approve the land-use plan if the county redesignated riparian zones as resource conservation areas, within which residential development was prohibited and parcels in contiguous ownership were merged, and adopted a minimum 100-ft. buffer zone around these lands.

As approved, the land-use plan prohibits development (including removal of vegetation except for flood control) on all riparian lands. Commercial timber harvests are not regulated by the plan; thus protection of riparian vegetation relies in large part on the designation of areas adjacent to riparian areas for rural residential use and other development at 1 unit per 8 ha. or more. The subdivision of these lands makes intensive forestry less feasible due to the loss of economics of scale necessary for long-term commercial timber production. This solution was acceptable to the county—the county relies primarily on public forest lands for its timber production (Proctor etal . 1980)—and was approved by the Coastal Commission because it reflected existing development trends in the area without jeopardizing the habitat values of the creek. Constitutional questions were minimized by merging adjacent parcels to provide larger lots where development could be sited on uplands beyond the buffer zone. The plan relies in large part on the inaccessibility, high water table, and lack of development pressure at Elk Creek to protect its riparian elements.

Eel River, Humboldt County

The Eel River flows from Mendocino and Humboldt County to enter the Pacific Ocean approximately 19 km. (12 mi.) southwest of Eureka. It enters the coastal zone near its junction with the Van Duzen River, and has a drainage basin of 923,000 ha. (2.28 million ac.). About 8,100 ha. of its watershed are within the coastal zone (fig. 3). Approximately 1,000 ha. of this area are forested riparian systems dominated by red alder, willow, and black cottonwood. Dense willow stands are common in areas with high water tables or subject to frequent high velocity water flows. Typical wildlife in the area includes all species previously identified plus additional species of cavity-nesting ducks, and raptors such as the White-tailed Kite (Elanusleucurus ) and Peregrine Falcon (Falcoperegrinus ), which hunt over adjacent farmlands. Winter raptor populations in the area are particularly high—as little as 1.3 km. of transect per bird^[6] —due in large part to the availability of riparian, wetland, and pasture vegetation in the area. Over 110 bird species dependent on riparian areas for some portion of their habitat requirements have been identified in the area.

[5] Agricultural general use provisions permit residential development at 1 unit per 8 ha. (20 ac.) and related development for grazing use, such as barns. Timberlands are intended for commercial timber use. Divisions to 1 unit per 8 ha. are permitted. Woodlot areas are forested rural residential lands with development permitted at 1 unit per 0.8 ha. (2 ac.).

[6] Pierce, H. 1981. Personal correspondence. California Department of Fish and Game, Eureka.

Figure 3.
Eel River delta, Humboldt County, California. Riparian
vegetation is located adjacent to the main stem
of the river (photo courtesy of NASA).

These riparian lands are a small remnant of the approximately 4,000 ha. (10,000 ac.) of the redwood/Sitka spruce/black cottonwood forest that occupied the Eel River delta floodplain at the advent of human settlement. Most of these lands were converted to grazing use because of their highly productive soils. Together with pasturelands on diked tidal marshes, they account for over half the cultivated agricultural land in Humboldt County's coastal zone and are the heart of the county's dairy industry (Humboldt County Planning Department 1979). Where forested riparian zones remain along the river, they are restricted to either the immediate channel corridor or to one of three large vegetation blocks located on oxbows, islands, or major turns in the river. Within these areas, conifers, which show clearly in historic photos of the same locations, are scarce. Portions of these areas were highly disturbed by flooding in 1955 and 1964. Aerial photos of the area show that mature red alder/black cottonwood forests occupy 33% of its riparian systems, followed by young black cottonwood/red alder stands occupying 23%, mixed red alder/willow stands occupying 32%, and grassland/forb pastures with scattered willows and red alder occupying 12%.

The retention of this vegetation pattern is in large part due to deliberate decisions by riparian landowners in response to past experience with flood damage and bank erosion. Eel River farmers have stated that most areas of black cottonwood/red alder vegetation have been retained because of their value in controlling flood-borne drift and coarse sediments which damage adjacent agricultural lands and structures. Most young red alder/willow patches are flood-damaged pastures abandoned after the 1955 or 1964 floods. Landowners of these sites may lack sufficient capital to reclaim the land. Where floodwaters deposit coarse sediments, property owners rely on riparian vegetation to slow the floodwaters, allowing them to drop finer soil particles. Some landowners have retained or even planted willow areas to retard bank erosion.

Most landowners have resisted policies which require retention of existing riparian vegetation. Increased wood chip or pulp wood prices may entice some owners of black cottonwood/red alder stands to harvest their riparian forest lands, even at the risk of increased flood damage. If the owners do not farm on valley pasturelands, there is little incentive to maintain mature forest stands. Where mixed red alder/willow stands occupy flood-damaged areas, property owners may anticipate additional silt deposition, or capital savings may permit reclamation of the site for agriculture. Local farmers have stated that several of these areas have gone through successive cycles of flood damage, forest growth, and clearing since the 1900s. Where construction of bank protection or changes in the river channel have reduced erosion hazards, property owners may decide to clear willow stands. Few landowners are willing to forego such uses as selective timber harvest or firewood removal, which retain riparian woodland stands but damage some habitat components essential to the area's diverse wildlife populations. Finally, almost all landowners wish to retain maximum flexibility of land use to respond to the dynamics of an area where, as one farmer stated: "The Eel owns the first mortgage and the bank gets the second" (Humboldt County Planning Department 1980b).

The Humboldt County Planning Department (1981b) recommended a local coastal plan focused on protecting old-growth black cottonwood/red alder stands, restoring degraded riparian systems, potentially converting some willow/alder stands, and retaining a forested riparian corridor along the river channel. The policies provided:

(1) The total acreage of the riparian corridor shall be established as a minimum base line for riparian vegetation on the Eel River; (2) Three areas of older age class riparian vegetation, comprised of old cottonwoods and alders, are designated Natural Resource. These areas are significant wildlife habitats and are critical to flood protection of adjacent prime agricultural lands and maintenance of the present river channel locations. To insure long term protection of these resources, the County encourages the purchase of these lands in fee title or through easements from willing sellers. Permitted uses within the Natural Resources designation include management for fish and wildlife, development of hunting blinds and similar minor facilities, and removal of trees for

firewood, disease control, or public safety purposes. (3) Removal of riparian vegetation outside the three Natural Resource areas is subject to the following policies: (A) The total acreage of the riparian vegetation shall be maintained by: (i) Encouraging the replanting of riparian vegetation from the stream transition line to the river channel; (ii) Planting of riparian vegetation as part of bank protection projects; (iii) Prohibiting conversions of riparian woodlands to other uses which would decrease the total amount of riparian vegetation below the minimum base line amount, or which would clear riparian vegetation within 200 feet of the stream transition line; and (iv) Limiting removal of vegetation, other than conversions, to timber management, selective timber and firewood harvests, and other minor or incidental uses. (ibid .)

The proposed land-use plan would protect the principal riparian systems from conversion to agricultural use. By encouraging replanting of unvegetated riparian areas and permitting conversion of some younger stands of riparian vegetation only if the total acreage of riparian vegetation on the river increased above existing levels, the plan provides incentives for restoring riparian woodlands on underutilized farmlands or flood-damaged river bars. These policies and those which tie riparian corridors to the river's stream transition line, permit adjustment of protected riparian areas with changes in either the river channel or vegetation patterns. The plan maintains traditonal use of mature riparian stands, including firewood cutting, and identifies additional economic uses such as commercial timber management and harvest in other riparian areas.

The proposed plan has not gained the approval of either fish and wildlife agencies or local agricultural interests and their representatives on the County's Planning Commission. The DFG has criticized the plan for permitting such uses as firewood harvests or timber management, which may remove important habitat components or change the composition of tree species in riparian areas. The DFG pointed out the uncertainty of long-term maintenance of restored riparian systems due to damage by high velocity floodflows or erosion, arguing that conversion of existing stands in exchange for restoring damage-prone areas may result in a long-term reduction in riparian acreage.

Agricultural interests, on the other hand, believe that restricting large areas to natural resource use deprives them of reasonable economic returns from their land holdings. They point out that neither the county nor other agencies have identified funding sources for public purchase of the Natural Resource areas. Most farmers realize the difficulty of any riparian restoration program, and their own limited ability to reclaim riparian areas for agricultural use. Lands suitable for restoration may not even be located on parcels in the same ownership as those proposed for conversion, necessitating a complex process of land acquisition, leaseholdings, etc.

The plan's potential to protect riparian systems is also undermined by the county's limited responsibility under the Coastal Act to control commercial timber harvests. Commercial timber harvests approved by the Department of Forestry (DF) are not subject to regulation by local coastal programs, and large expanses of riparian vegetation may be harvested for woodchips.^[7]

Because the Coastal Commission did not anticipate the effect of chip price increases on the value of the Eel River's riparian woodlands, it did not designate the river's riparian systems as special treatment areas (see discussion of Big River below). Present timber harvest rules offer little protection for the area's riparian values.

Important information necessary to the plan's implementation is lacking. Sites suitable for restoration of riparian vegetation, successful restoration techniques, or funding sources for restoration programs have not been identified. Standards for commercial timber management or firewood harvests which can provide both economic uses and habitat protection have not been identified. Timber management techniques from European or eastern hardwood stands may be applicable (e.g., see Stewart 1981). However, local residents, foresters, and biologists are unfamiliar with these techniques, and their likely impact on wood production or habitat protection is not known.

The Eel River lacks the components which led to agreement on riparian protection for Elk Creek. The Eel River's riparian systems hold resources important to local interest groups and for which substitutes are not available. High soil productivity and exposure to flood hazards make protection of riparian areas as part of residential development infeasible. The absence of special treatment area standards for timber harvest plans leaves the area exposed to significant habitat damage during commercial logging. It appears that a plan lacking a substantial

[7] Red alder may be considered a commercial species in timber harvest plans at the option of the professional forester preparing the plan. Black cottonwood and willow are not subject to timber harvest plans. Because of these administrative guidelines and local government's absence of jurisdiction over logging under timber harvest plans, the county can assure protection of only some components of the riparian systems. The degree of protection will be in large part determined by landowners' decisions to file timber harvest plans for red alder stands, or to manage them for other uses consistent with the county's plan.

public funding committment for purchase of riparian woodlands will not ensure protection of the Eel River's habitat values.

Big River, Mendocino County

Big River, with a drainage basin area of approximately 42,500 ha. (105,000 ac.), is located in central Mendocino County and drains into the ocean through an estuary extending up to 13 km. (8 mi.) above the river's entrance to Mendocino Bay. Approximately 1,500 ha. of the drainage basin are located within the coastal zone. Big River is a drowned river valley rather than a broad alluvial flat.

Riparian systems at Big River are characterized by dense, mature second-growth redwood forests with an understory of grand fir (Abiesgrandis ), red alder, California nutmeg (Torreyacalifornica , and tanoak (Lithocarpusdensiflorus ). Red alder dominates riparian areas on natural levees between the estuary and the redwood forest (fig. 4). Willows, Oregon ash (Fraxinuslatifolia ), and cascara (Rhamnuspurshiana ) are common in alder-dominated forests. Adjacent uplands are coniferous forests with Douglas fir (Pseudotsugamenziesii ), redwood, and western hemlock (Warrick and Wilcox 1981).

Figure 4.
Riparian vegetation on Big River, Mendocino County.

Seacat, Seymour, and Marcus (Warrick and Wilcox 1981) identified 10 bird species in mature redwood forest and 23 species in harvested redwood forests. Species lists for the Big River area include most wading birds and waterfowl which nest or roost in riparian systems, but lack the diverse raptor populations found at Elk Creek and Eel River.

Timber has been harvested at least once in most of the river's watershed. Warrick and Wilcox (ibid .) reported that red alder-dominated riparian forests have increased along the river channels, in what were previously estuarine systems, due to accretion of sediments generated by upriver timber harvests.

Mendocino County's local coastal plan designates alder-dominated forests as riparian vegetation. Redwood forests, together with upland redwood/Douglas-fir communities are designated for forest use. Policies for their development include:

(1) Development within 100-foot wide riparian corridors adjoining perennial and intermittent streams and riparian vegetation shall be regulated by Policy 2. Riparian corridors shall be measured from the landward edge of riparian vegetation, or, if no vegetation exists, from the top edge of the stream bank; (2) No structure or development, including dredging, filling and grading, which could degrade the riparian area or detract from its value as a natural resource shall be permitted in the riparian corridor except for: measures necessary for flood control; pipelines, utility lines and road crossings; timber harvesting operations, as regulated by the Forest Practices Act; and collection of firewood, if not more than 25 percent of the forest canopy is lost to cutting over a ten year period; (3) The implementation phase of the LCP shall include preparation of performance standards and/or recommendation of mitigation measures applicable to allowable development within riparian corridors. These standards and measures shall minimize potential development impacts such as increased runoff, sedimentation, biochemical degradation, increased stream temperatures and loss of shade caused by development. When development activities require removal or disturbance of riparian vegetation, replanting with appropriate native plants shall be required; (4) Where riparian vegetation exists away from stream corridors, development shall be minimized; (5) In timberland units of commercial size, permitted uses shall be limited to timber production and related harvesting and processing activities; seasonal recreational uses not requiring permanent structures; management of land for watershed maintenance, grazing and forage, and fish and wildlife habitat; construction and maintenance of gas, electric, water or communication transmission facilities; and residential uses as described in Policy 6; (6) Parcels entirely occupied by timberlands of commercial size shall have not more than one housing unit per 160 acres or 4 units per parcel. (Blayney-Dyett 1980)

Riparian systems of Big River are located entirely on unroaded floodplains with high water tables, and residential development on them is

improbable. In this regard, they are much like riparian areas at Elk Creek. Unlike Elk Creek, however, Big River's riparian systems are extraordinarily productive commercial timberlands which provide a significant portion of the coastal Mendocino County sawlog resources. They are owned by a major timber company whose Fort Bragg sawmills provide a substantial percentage of employment in the area.

All riparian forests and some of the adjacent uplands at Big River were designated as forestry special treatment areas. Commercial timber production is the most likely use of this riparian vegetation, and the California Board of Forestry's timber practice rules for Coastal Commission special treatment areas will be central to protecting habitat values of this vegetation. In addition to the practices prescribed for all timber harvests in the Coast Forest District, the rules generally require: (1) protection of live trees with visible evidence of current nesting by endangered species, raptors, waterfowl, or wading birds. Forest practice rules outside of special treatment areas only require protection of endangered species nesting sites, and encourage protecting trees used as nesting sites by eagles and osprey; (2) stream protection zones 46 m. (150 ft.) wide on each side of perennial streams and 30 m. (100 ft.) on each side of intermittent streams. Within these stream protection zones, 50 to 70% of the total tree canopy and 50% of all other vegetation must be left standing. Forest practice rules outside of Coastal Commission special treatment areas require stream protection zones 30 m. (100 ft.) wide on perennial streams and 15 m. (50 ft.) on intermittent streams, within which 50% of the stream-shading canopy must be left standing; (3) a 4 ha. (10 ac.) maximum limitation on clear-cut size. Clear-cuts outside of special treatment areas are limited to a maximum 32 ha. (80 ac.) size.

These timber practice rules can mitigate harvest impacts on many components of Big River and other coastal riparian forests. Rules which protect nesting sites or tree canopies and other vegetation adjacent to the river and its tributaries can maintain feeding, nesting, and roosting sites for riparian wildlife. Limiting clear-cut size can reduce the effects of timber removal outside the stream protection zones, providing a variety of habitat-types as large timberland areas are rotated through successive cycles of harvest and forest growth. However, the rules cannot ensure protection of old-growth vegetation or long-term maintenance of such unique habitat components as snags, which are essential to some riparian wildlife. Nor can they protect riparian systems from the adverse impacts of timber harvests beyond the boundaries of the special treatment area.

Protecting riparian systems at Big River by acquisition is unlikely. In 1979, the USDI Fish and Wildlife Service (FWS) proposed acquiring up to 610 ha. (1,500 ac.) of the Big River watershed including both red alder and redwood riparian areas (USDI Fish and Wildlife Service 1979). Acquisition was not supported by the Coastal Commission which, in its comments on the proposal, cited Coastal Act policies preventing conversion of commercial timberlands to other uses. The acquisition proposal was opposed by the landowner and Mendocino County, both of which feared adverse effects on sawlog supplies for the company's Fort Bragg mill. The proposal was eventually withdrawn by the FWS due to this local opposition and, perhaps, the rapid escalation of redwood timberland prices following the Redwood National Park expansion.

Conclusion

These examples demonstrate the potentials and limitations of regulatory land-use controls in protecting riparian systems. Even an agency with the broad regulatory authority of the Coastal Commission is limited in its ability to protect riparian areas. The limitations are due in part to conflicting objectives—a problem which besets most resource management agencies. The Coastal Commission's limited jurisdiction over timber harvests has presented both opportunities and constraints to the Commission's ability to protect northcoast riparian forests. The Commission has been relatively successful in protecting riparian corridors along small coastal streams and larger patches of riparian vegetation. In the northcoast region, however, its ultimate ability to maintain large riparian systems is in doubt, partly due to limited public understanding of these values and partly to the reluctance of local government to restrict large areas to wildlife habitat use. This reluctance is attributable both to goals of increased economic development and concerns about constitutional protection of property rights. Protecting large, coastal riparian systems through land-use regulation may be successful where these limitations can be overcome. In some areas, effective protection can be achieved only through public purchase. However, even when acquisition funding is available, other social goals may make protection of large riparian systems infeasible.

What do these lessons from the coastal zone suggest for others interested in protecting riparian systems? First, protection must begin with improved information about habitat processes in riparian areas. That information must be effectively transferred to the public. Current developments in wetland protection, for example, are the result of decades of research and public education through sportsmen, conservationists and public information programs. Similar efforts for riparian ecosystems are only beginning.

Second, land-use regulation can successfully protect small riparian areas, but can rarely do more than mitigate impacts in large systems. With effective land-use policies and adequate agency jurisdiction, large riparian areas can be protected from conversion. Forest practice rules can be effective in mitigating the impacts of timber harvest on many components of riparian

systems. Extending forest practice rules to cover harvesting of riparian hardwoods and incorporating features of the harvest standards for Coastal Commission special treatment areas into the management of all riparian woodlands would reduce damage to habitat values. In addition, amendment of the forest practice rules to take into consideration critical riparian habitat features by providing, for example, adequate long-term snag recruitment and maintenance of dead and down wood, would help protect wildlife populations dependent on these special habitat components.

Third, a long-term acquisition program for critical riparian systems will be necessary to protect areas where regulation is infeasible or inadequate. Any acquisition program should be based on a statewide or regional assessment of long-term habitat protection objectives, rather than a response to immediate "brushfires". The FWS concept plan for waterfowl wintering habitat preservation is a good example of a long-term program for habitat protection.

Finally, you can't win them all. Some important riparian systems will not be protected despite strong land-use planning and well-planned acquisitions. Wildlife agencies should begin planning to restore degraded riparian areas, to compensate for these unavoidable losses. Potential restoration sites should be identified and restoration activities begun. Within the northcoast region, degraded riparian areas suitable for habitat restoration are located on many existing public lands. Such a restoration program may prove more effective in compensating for unavoidable damage to riparian ecosystems than recommendations for extensive mitigation as part of development projects and could take advantage of funding from a variety of sources, including in-lieu fees collected from projects which degrade riparian areas.

Acknowledgments

The authors wish to thank Herbert Pierce, Thomas Stone, and Gary Monroe, California Department of Fish and Game; Bruce Fodge, California Coastal Commission; and Donald Tuttle and Patricia Dunn, Humboldt County Public Works and Planning departments, for their interest and assistance in the development of the data, concepts, and land-use policies discussed in this report.

Literature Cited

Blayney-Dyett. 1980. Coastal element, Mendocino County general plan. 191 p. California Coastal Commission, San Francisco, Calif.

Del Norte County Planning Department. 1980. Local coastal program land use plan. 384 p. Del North County Planning Department. Crescent City, Calif.

Forman, R.T.T., A.E. Galli, and C.F. Leck. 1976. Forest size and avian diversity in New Jersey woodlots with some land use implications. Oecologia 26:1–8.

Galli, A.E., C.F. Leck, and R.T.T. Forman. 1976. Avian distribution patterns in forest islands of different sizes in central New Jersey. Auk 93:356–364.

Gates, J.E., and L.W. Gysel. 1978. Avian nest dispersion and fledging success in fieldforest ecotones. Ecology 59:871–883.

Harris, S.W. 1973. Birds and their habitats in the mid-Humboldt region. 22 p. Unpublished report. On file at Humboldt State University, Arcata, Calif.

Humboldt County Planning Department. 1978. Habitats sensitivity technical study. 103 p. Humboldt County Planning Department. Eureka, Calif.

Humboldt County Planning Department. 1979. Agriculture technical study. 23 p. Humboldt County Planning Department. Eureka, Calif.

Humboldt County Planning Department. 1980a. North-coast area plan. 75 p. Humboldt County Planning Department. Eureka, Calif.

Humboldt County Planning Department. 1980b. Eel River area plan. 100 p. Humboldt County Planning Department. Eureka, Calif.

Humboldt County Planning Department. 1981a. South-coast area plan. 74 p. Humboldt County Planning Department. Eureka, Calif.

Humboldt County Planning Department. 1981b. Staff recommendation—Eel River area plan. 16 p. Unpublished report. On file at Humboldt County Planning Department, Eureka, Calif.

Leipzig, P. 1972. Wildlife inventory, midHumboldt County area. Unpublished report. 15 p. On file at Humboldt State University, Arcata, Calif.

Mac Arthur, R.H., and E.O. Wilson. 1967. The theory of island biogeography. Princeton monogr. in Pop. Biol. No. 1, Princeton University Press, Princeton, J.J. 203 p.

Marcot, B.G. (ed.). 1979. California wildlife/habitats relationships programs—North Coast/Cascades zone. Vol. 1–5. 1136 p. Six Rivers National Forest, USDA Forest Service, Eureka, Calif.

Monroe, G.W. 1974. Natural resources of the Eel River delta. California Department of Fish and Game, Coastal Wetlands series No. 9, Sacramento, Calif. 108 p.

McLaughlin, J., and F. Harradine. 1965. Soils of western Humboldt County. 84 p. Department of Soils and Plant Nutrition, University of California, Davis.

Pickett, S.T.A., and J.N. Thompson. 1978. Patch dynamics and the design of nature reserves. Biol. Conserv. 13:27–37.

Proctor, C.M., J.C. Garcia, D.V. Gaulin, T. Joyner, G.B. Lewis, L.C. Loehr, and A.M. Massa. 1980. An ecological characterization of the Pacific Northwest coastal region. Vol. 1–5. USDA Fish and Wildlife Service, Biological Services Program. FWS/OBS-79/11 through 79/15. Washington, D.C.

Roberts, W.G., J.G. Howe, and J. Major. 1977. A survey of riparian forest flora and fauna in California. p. 3–20. In : A. Sands (ed.). Riparian forests in California—their ecology and conservation. Institute of Ecology Pub. No. 15. 122 p. University of California, Davis.

Schoener, T.W. 1968. Sizes of feeding territories among birds. Ecology 49:123–141.

Stewart, P. 1981. Coppicing with standards. Coevolution Quarterly 30:56–61.

Strahler, A.N. 1964. Quantitative geomorphology of drainage basins and channel networks. Section 4.2. In : Ven to Chow (ed.). Handbook of applied hydrology. McGraw-Hill, New York, N.Y.

Thomas, J.W. (ed.). 1979. Wildlife habitats in managed forests—the Blue Mountains of Oregon and Washington. USDA Forest Service Agricultural Handbook No. 553, Washington, D.C. 512 p.

Thompson, K.E., A.K. Smith, and J.E. Lauman. 1972. Fish and wildlife resources of the southcoast basin, Oregon, and their water requirements (revised). Oregon State Game Commission, Portland, Oregon.

USDA Forest Service. 1965. Soil-vegetation survey of Mendocino County. Pacific Southwest Forest and Range Experiment Station, USDA Forest Service, Berkeley, Calif.

USDI Fish and Wildlife Service. 1979. An environmental assessment of the Big River estuary, Mendocino County, California. 52 p. USDI Fish and Wildlife Service. Sacramento, Calif.

Warrick, S.F., and E.D. Wilcox (ed.). 1981. Big River—the natural history of an endangered northern California estuary. Environmental Field Program Pub. No. 6. 296 p. University of California, Santa Cruz, Calif.

Wilcox, B.A. 1980. Insular ecology and conservation. p. 95–117. In : M.E. Soulé and B.A. Wilcox (ed.). Conservation Biology. 305 p. Sinauer Associates, Sunderland, Mass.

Preserving Riparian Vegetation along California's South Central Coast^[1]

Mark H. Capelli and Stephen J. Stanley^[2]

Abstract—California's south central coast contains over 400 km. (250 mi.) of riparian vegetation within the Coastal Zone, concentrated principally in narrow corridors bordering short coastal streams. A great deal of this vegetation has been disturbed or destroyed by urban, agricultural, and related flood control activities. The South Central Region Coastal Commission and the State Coastal Commission have utilized their regulatory authority to reduce or avoid further disturbance of selected coastal riparian systems and have provided an example to local jurisdictions to follow in preparing of local coastal programs. The effectiveness of continued protection of riparian vegetation under local coastal programs, however, remains uncertain.

Introduction

In 1976, the California Legislature passed the California Coastal Act^[3] in response to a growing concern over the impacts of development on the natural and cultural resources of the California coast. The legislation was the immediate outgrowth of a voter initiative, Proposition 20,^[4] passed in 1972, which set up six regional commissions and one state commission. These commissions had interim authority to regulate development along the coast while a master coastal plan was being readied for submission to the California Legislature. The plan prepared by the original commission (California Coastal Zone Conservation Commission 1975) formed the basis for the Coastal Act of 1976 (the Act).

The Act re-established the regional and state commissions with interim authority over most types of development along the coast while local jurisdictions prepared local coastal programs (LCPs), consisting of a land-use plan and a zoning or implementation element. The LCPs were to be based on the environmental and development standards of Chapter 3 of the Act. The regional commissions were terminated after July 1981, leaving the State Commission with the responsibility of reviewing interim permit applications and LCPs.

The policies of the Act address planning issues ranging from protection and provision of affordable visitor facilities to maintenance of biological productivity of environmentally sensitive habitats. Included in the Act are strong policies regarding the protection and restoration of coastal streams and riparian vegetation. The most important of these include the following:

The biological productivity and the quality of coastal waters, streams, wetlands, estuaries, and lakes appropriate to maintain optimum populations of marine organisms and for the protection of human health shall be maintained and, where feasible, restored through, among other means, minimizing adverse effects of waste water discharges and entrainment, controlling runoff, preventing depletion of groundwater supplies and substantial interference with surface waterflow, encouraging waste water reclamation, maintaining natural vegetation buffer areas that protect riparian habitats, and minimizing alteration of natural streams (emphasis added).^[5]

(a) The diking, filling, or dredging of open coastal waters, wetlands, estu-

[1] Paper presented at the California Riparian Systems Conference. [University of California, Davis, September 17–19, 1981].

[2] Mark H. Capelli and Stephen J. Stanley are Coastal Analysts, South Central Coast Region, California Coastal Commission, Santa Barbara, Calif

[3] Public Resources Code (PRC) Section 30000-30900.

[4] Coastal Zone Conservation Act. 4 p. State of California, Sacramento.

[5] PRC 30231.

aries, and lakes shall be permitted in accordance with other applicable provisions of this division, where there is no feasible less environmentally damaging alternative, and where feasible mitigation measures have been provided to minimize adverse environmental effects, and shall be limited to the following:

(4) In open coastal waters, other than wetlands, including streams, estuaries, and lakes , [PRC 30233] (emphasis added).

Channelization, dams, or other substantial alterations of rivers and streams shall incorporate the best mitigation measures feasible, and be limited to (1) necessary water supply projects, (2) flood control projects where no other method for protecting existing structures in the floodplain is feasible and where such protection is necessary for public safety or to protect existing development, or (3) developments where the primary function is the improvement of fish and wildlife habitat [PRC 30236].

(a) Environmentally sensitive habitat areas shall be protected against any significant disruption of habitat values, and only uses dependent on such resources shall be allowed within such areas [PRC 30240].

To further clarify the intent of these policies, the State Commission in February 1981 adopted a set of "Statewide Interpretive Guidelines for Wetlands and Other Wet Environmentally Sensitive Habitat Areas" (California Coastal Commission 1981). These guidelines provide a working definition of riparian vegetation and standards for development adjacent to streams. Generally, a buffer area of at least 30 m. (100 ft.) is recommended for small projects such as a single-family residence; criteria for modifying setbacks from riparian vegetation and other environmentally sensitive areas are also provided. Additionally, before being terminated individual regional commissions adopted regional interpretative guidelines which addressed planning issues, including setbacks from identified environmentally sensitive areas located within their jurisdictions.

This paper provides a survey of the riparian resources within the South Central Region and the experience of the South Central Regional Commission (the Regional Commission) and the State Coastal Commission (the State Commission) in protecting these resources through the regulatory process established by the passage of the Act.

Regional Setting

The jurisdiction of the Regional Commission encompasses the coastal portions of San Luis Obispo, Santa Barbara, and Ventura counties with a combined coastline of 412 km. (256 mi.) (fig. 1). The Coastal Zone boundary line generally runs 914 m. (1,000 yds.) inland from the mean high-tide line. Notable exceptions to this boundary include portions of northern San Luis Obispo County from the Monterey County line south to Villa Creek, the Morro Bay watershed, the Guadalupe and Nipomo Dunes in southern San Luis Obispo and northern Santa Barbara counties, the Hollister and Bixby ranches also in northern Santa Barbara County, the Carpinteria Valley in southern Santa Barbara County, and portions of the Santa Monica Mountains in southern Ventura County to the Los Angeles County line. In these areas the Coastal Zone extends inland 4.8–8.0 km. (3–5 mi.).

Figure l.
South Central Coast Regional Commission jurisdiction (counties).

Geology and Hydrology

The topography of the South Central Region is dictated principally by the eastward-trending Transverse Ranges which stretch across Ventura, Santa Barbara, and southern San Luis Obispo counties (Oakeshott 1978). The topography of north San Luis Obispo County is shaped by the north-south trending Santa Lucia Mountains of the South Coast Ranges. Both of these ranges are made up of recently uplifted, highly folded and fractured marine and terrestrial sediments. The inland portions of these ranges extend up to 3,050 m. (10,000 ft.), but average only about 760 m. (2,500 ft.) immediately adjacent to the coast. Alluvial and wave-cut terraces have been formed and exposed by the recent uplift of the ranges, creating the setting for much of the modern human development which has occurred during the last 100 years.

The ranges of the Coast and Transverse Provinces have been dissected by faults, broadly alluviated synclinal valleys, and steep, narrow stream canyons (Norris and Webb 1976). The climate of the South Central Region is classified as Mediterranean, with two distinct seasons—a long dry summer and a short mild winter, with most of the precipitation occurring between December and March. The average annual rainfall varies from 1,016 mm. (40 in.) in the mountainous areas to less than 380 mm. (15 in.) along the coast (Bailey 1966).

Four major coastal river systems drain the South Central Region: the Santa Maria and Santa Ynez rivers in Santa Barbara County; and the Ventura and Santa Clara rivers in Ventura County. There are, however, approximately 100 smaller coastal streams and creeks distributed throughout the three counties. Because of the short rainfall season, most of these rivers, streams, and creeks maintain year-round surface flows only along portions of their length, though groundwater is commonly present near the surface in sufficient quantity to support riparian vegetation. Altogether there are approximately 417 km. (259 mi.) of perennial, intermittent, or interrupted watercourses within the South Central Region. In addition, the coastal terraces at sea level contain numerous lagoons and estuaries which are bordered by stands of riparian vegetation. The largest and most productive are: Morro Bay in San Luis Obispo County; the Santa Maria and Santa Ynez river mouths; Goleta Slough and Carpinteria Slough in Santa Barbara County; and the Santa Clara River mouth and Mugu Lagoon in Ventura County.

Vegetation

The highest elevations of the Coast and Transverse ranges are vegetated with scattered stands of conifers (Latting 1976), including Coulter pine (Pinuscoulteri ), digger pine (Pinussabiniana ), and big cone spruce (Pseudotsugamacrocarpa ). Most of both ranges, however, is covered with a dense mixture of chaparral species such as big pod ceanothus (Ceanothusmegacarpus ), chamise (Adenostomafasciculatum ), east wood manzanita (Arctostaphylosglandulosa ), laurel sumac (Rhuslaurina ), toyon (Heteromeles arbutifolia ), and white sage (Salviaapiana ). These shrub-like species sometimes assume a tree-like habit and are associated with numerous herbaceous species, including perennial and introduced annual grasses.

Riparian plant communities are generally restricted to narrow bands adjacent to perennial, intermittent, or interrupted watercourses at the bottom of canyons (Sands 1977). Although these riparian corridors constitute less than 2% of the total vegetative cover, they provide habitat for more than 50% of the indigenous species. At the higher elevations, the riparian community may include an overstory of tree species such as western sycamore (Platanusracemosa ), black cottonwood (Populustrichocarpa ), California bay (Umbellulariacalifornica ), coast live oak (Quercusagrifolia ), and white alder (Alnusrhombifolia ). In the lower reaches of the watercourses, which are the portions most often encompassed within the Coastal Zone, the dominant riparian species are arroyo willow (Salix lasiolepis ), and yellow willow (Salixlasiandra ).

These lower reaches are also characterized by a variety of herbs and emergent aquatics, including coyote bush (Baccharis pilularis ), wild blackberry (Rubusursinus ), nettle (Urticaholosericea ), and sedges (Juncus spp.). Near the mouths of most coastal streams, the riparian species begin to be replaced by more salttolerant wetland species such as salt bush (Atriplexpatula ), salt grass (Distichlisspicata ), cattail (Typhalatifolia ), bulrushes (Scirpus spp.), and pickleweed (Salicorniavirginica ) (Mason 1969; Munz 1974; Barbour and Major 1977; Hoover 1970; Smith 1976).

Threats to Riparian Resources

The South Central Region has the third highest growth rate of the six coastal regions (California Coastal Commission 1980). This rate of development has generated conflicts between the Coastal Commission's legal obligation to protect environmentally sensitive habitats, such as riparian vegetation, and the pressure to convert, encroach upon, or otherwise disturb such areas to accommodate development. Urban developments include such diverse activities as land divisions creating marketable or usable building sites; single-family or multi-family residential development; public and private recreational developments such as day-use and recreational vehicle parks; public utilities such as wastewater treatment plants; and commercial and industrial developments including energy facilities. Agricultural developments include greenhouses; floodplain areas cleared for vegetable and flower row crops; tree crops on steep slopes from which the native vegetation has been removed; and cattle grazing.

These developments can result in the modification of adjacent riparian vegetation and of the watercourses themselves. Aside from the actual encroachment of development into the riparian system, flood control projects designed to protect development adjacent to watercourses have also had a major impact on riparian systems. The most common flood control activities include clearing vegetation from channels; realigning and straightening meandering watercourses; and lining channel banks with concrete, riprap, or gabions. Surface diversions and private wells sunk into aquifers have also adversely affected riparian vegetation. Some of the ways these activities and developments have been handled by the Regional Commission and the State Commission through the interim permit process and review of LCPs in the three counties are discussed below.

Regional and State Commission Experience

San Luis Obispo County

Setting and Issues

San Luis Obispo County has a coastline of approximately 160 km. (100 mi.). Within the Coastal Zone, there are 48 named streams with a total length of 262 m. (163 mi.) of riparian vegetation. Some of the most important riparian vegetation is found along San Carpoforo, Arroyo de la Cruz, San Simeon, Santa Rosa, Cayucos, Morro, Little Morro, Chorro, Pismo, Arroyo Grande, and Los Osos creeks (fig. 2). Riparian vegetation is also found along portions of the Morro Bay estuary and the freshwater lakes within the Guadalupe and Nipomo Dunes.

Riparian systems along the north county coast have been affected by livestock grazing activities. Public and private commercial developments to serve visitors in the communities of San Simeon, Cambria, and Cayucos have encroached upon stream corridors near their mouths. Proposed private recreational developments requiring the exploitation of local groundwater supplies also pose a potential threat to riparian vegetation which is undisturbed at present. In the southern half of the county, riparian systems have been affected by a variety of residential, recreational, commercial, and public works developments.

Figure 2.
Lagoon and lower reaches of Arroyo
de la Cruz, San Luis Obispo County.

The Regional Commission and the State Commission have had occasion to deal with a number of these issues on a case-by-case basis, through their interim permitting process and through review of LCPs prepared by the county and the cities of Morro Bay, Pismo Beach, and Grover City. Some examples of these and their dispositions are presented below.

Permits

Charles Bagwell .—The applicant, Charles Bagwell, had proposed the creation of four lots of 0.4 ha (1 ac.) each for detached, singlefamily residential development from a 3.9-ha. (9.6-ac.) parcel situated adjacent to the southern border of the Pismo Lake Ecological Reserve.^[8] The reserve, which is owned and managed by the California Department of Fish and Game (DFG), is fed by Meadow Creek and is bordered by thick stands of arroyo willow. The subject parcel consisted primarily of a steep slope, dipping toward the reserve, vegetated with coast live oak and having a strand of riparian vegetation on the north side. The applicant had proposed locating the building sites on the back side of the ridge, away from the reserve, but incorporated most of the oak and riparian woodland into one of the building sites.

The Regional Commission found that the proposed development, which the land division would have facilitated, posed a serious potential threat to the oak and riparian woodlands and the adjacent Pismo Lake Ecological Reserve. Accordingly, the Regional Commission approved the land division with the condition that the applicant offer to Grover City, or if the city refused, the DFG, a 2-ha. (5-ac.) portion of the parcel containing all of the oak and riparian woodland, for the purpose of protecting the woodlands and adjoining reserve in perpetuity. The land was ultimately accepted by the city, with the further requirement that it be managed as an integral part of the Pismo Lake Ecological Reserve and subject to the regulatory provisions governing all state ecological reserves.

Aqueduct Farms , Inc .—In a project related to the above development, the applicant proposed dividing 12.6 ha. (31 ac.) of land on the north side of the Pismo Lake Ecological Reserve into three parcels (4.5 ha. [11 ac.], 5.3 ha. [13 ac.], and 2.0 ha. [5 ac.]) to accommodate general commercial and recreational developments.^[9] Portions of the original parcel had been disturbed by filling and grading. The remainder consisted of gently rolling swales and ravines dipping down toward the reserve. These portions of the property were vegetated with a combination of coastal sage scrub species and a variety of herbs and other introduced grasses; the area adjacent to the reserve was dominated by arroyo willow. The Regional Commission allowed the creation of the building sites on the already disturbed areas and a small portion of the site with the shallowest gradient (less than 20%), but required the applicant to offer to the DFG the remaining 6.1 ha. (15 ac.) to be incorporated into the Pismo Lake Ecological Reserve.

[8] South Central Coast Regional Commission. 1978. Application and permit 133-08: Charles Bagwell. On file with the South Central Coast District Office, Santa Barbara, Calif.

[9] South Central Coast Regional Commission. 1979. Application and permit 205-15: Aqueduct Farms, Inc. On file with the South Central Coast District Office, Santa Barbara, Calif.

California Department of Parks and Recreation/San Luis Obispo County Flood Control District .—The applicants proposed clearing 2,748 cu. m. (3,600 cu. yd.) of sediment from 396 m. (1,300 ft.) of Los Osos Creek, which discharges into the southern end of the Morro Bay estuary. The purpose of the channel clearing was to increase the floodflow capacity of the channel and protect an adjacent local road from flooding.^[10] The project as proposed would have entailed the use of a drag-line bucket from the adjacent frontage road. This technique would require removal of the mature riparian canopy, consisting of arroyo willow, on the west bank and trimming back of willows on the east bank so that the drag-line bucket could be drawn along the channel.

While recognizing the need to alleviate the periodic flooding of the adjacent road, the Regional Commission sought to reduce the impacts of the channel clearing by requiring the applicants to submit an alternative plan which did not require the removal of any mature willows and minimized any necessary trimming. One possible alternative method of clearing out sediment and instream vegetation would utilize a "clamshell" dredge, which can be operated more selectively and only requires minimal trimming of the riparian canopy. Because removal of any vegetation, whether instream or riparian, would result in increased sedimentation of the Morro Bay estuary, the Regional Commission also recommended that future applications for stream modifications of Los Osos Creek be accompanied by an erosion control plan which identified the sources of sediments in Los Osos Creek and provided mitigation measures designed to eliminate excess stream sedimentation.

Local Coastal Plans

Within San Luis Obispo County, LCPs are being prepared by Morro Bay, Pismo Beach, Grover City, and the County for their respective jurisdictions. These plans are in various stages of completion and have undergone review by either the Regional Commission or the State Commission or their staffs. To date, however, only Grover City has received certification of both its land-use plan and implementing zoning ordinances. Nevertheless, a brief review of the proposed plan policies regarding the protection of riparian vegetation indicates the range of interpretation of the policies of the Act developed by local jurisdictions.

MorroBay .—The principal riparian resources within the jurisdiction of the city of Morro Bay are found along Morro, Little Morro, and Chorro creeks (Morro Bay 1981). In response to Coastal Commission staff review of the draft LCP Land Use Plan, the city staff proposed policies to provide protection of these resources. Several of these policies are summarized below.

Policy 11.14 establishes buffer strips along all streams. The minimum buffer must be 100 ft. in rural areas and 50 ft. in urban areas. These requirements can be adjusted on a case-by-case basis, taking into consideration conditions in the stream corridor, including: 1) soil types and stability; 2) how surface water filters into the ground; 3) slope of the land on either side of the stream; and 4) location of the 100-year floodplain. Riparian vegetation within the buffer is to be protected, and where vegetation has been previously removed the buffer should allow for its re-establishment.

Policy 11.15 prohibits all structures within stream corridors. There are exceptions to this prohibition, including public trails, flood control projects (only where no other method of protection of existing development is feasible), and improvements of fish and wildlife habitat. All development permitted in the stream corridor must incorporate mitigation measures for any impacts on the stream corridor.

Policy 11.16 prohibits any dredging, filling, or grading within the stream corridor, except as a part of the construction activities specified above. If riparian vegetation must be removed, revegetation is required except where undesirable for flood control purposes.

Pismo Beach.—Pismo Creek (fig. 3) and Meadow Creek (including the Pismo Lake Ecological Reserve) support the most important riparian systems in the city (Pismo Beach 1980). The city proposed a set of policies to protect these resources.

After carefully reviewing these policies, the State Commission found that they did not meet the requirements of the Act and denied certification of the Pismo Beach Land Use Plan. The State Commission staff recommended specific and stringent standards for development adjacent to stream and riparian systems. These recommendations included: 1) designation of all wetland and riparian areas as environmentally sensitive habitat; 2) buffer zones for all environmentally sensitive habitat areas, including specific recommendations of buffer size in various areas, mitigation measures where buffer sizes do not meet minimum criteria, and permitted activities within the buffer zone; 3) impact assessment for any development adjacent to the buffer area; 4) prohibition of land division within the environmentally sensitive areas; and 5) specific activities which may be permitted within the stream, and conditions to and limitations on those activities.

GroverCity .—The riparian vegetation along the south bank of Meadow Creek and the Pismo Lake Ecological Reserve constitute the major riparian resources within Grover City

[10] South Central Coast Regional Commission. 1981. Application and permit 424-01: California Department of Parks and Recreation and San Luis Obispo County Flood Control District. On file with the South Central Coast District Office, Santa Barbara, Calif.

Figure 3.
Lagoon and lower reaches of Pismo
Creek, San Luis Obispo County.

(Grover City 1981). After considering policies proposed by the City to protect these resources, the State Commission certified Grover City's Land Use Plan with several site-specific policies that addressed: 1) erosion control; 2) development near and/or disturbance or removal of shagbark manzanita and coast live oak; and 3) the buffer area for Meadow Creek.

San Luis Obispo County .—San Luis Obispo County has jurisdiction over most of the riparian resources within the county (San Luis Obispo (County 1981). This includes over 258 km. (160 mi.) of streams, primarily situated on rural or undeveloped lands in the northern portion of the county, north of Morro Bay. Consequently, the county's policies have a major influence on the future protection of riparian resources. The county has approved its Land Use Plan and submitted it to the State Commission staff for review. The principal policies proposed by the county provide for streamside buffer zones (size requirements, types and intensities of use, and mitigation measures to protect the stream), permitted types of and required procedures for streambed alteration, and protection of riparian vegetation.

The State Commission had not reviewed the San Luis Obispo County LCP at the time of writing [September 1981]; however, the riparian policies proposed by the county do differ in several important respects from those approved by the State Commission for Santa Barbara County (see discussion below).

Santa Barbara County

Setting and Issues

The Santa Barbara coastline is approximately 182 km. (113 mi.) long and is characterized by moderate to steep coastal ranges. The Mussel Rock and Vandenberg Dune areas, as well as the Carpinteria Valley, are exceptions to this general pattern (Dibblee 1950, 1966). As a result of the proximity of steep mountain ranges, the county's coastal area contains a high percentage of steep gradient streams and creeks. There are 72 streams with a total length of 134 km. (83 mi.) in the county's Coastal Zone. Of these watercourses, 25 are perennial and 47 are intermittent or ephemeral. There is only one stream with a perennial flow in the Coastal Zone east of the unincorporated community of Goleta, the most urbanized portion of the Santa Barbara County Coastal Zone. The balance of the perennial streams are located up-coast in the rural portion of the county.

Coastal streams of particular note in the county, from north to south, include the Santa Maria and Santa Ynez rivers, and San Antonio, Jalama, Tecolote, Toro Canyon, Santa Monica, Franklin, Carpinteria, and Gaviota creeks. In addition, there are several short coastal streams with perennial or intermittent flows on the Hollister and Bixby ranches in northern Santa Barbara County. Important coastal wetlands with bordering riparian vegetation include the mouths of the Santa Maria and Santa Ynez rivers (fig. 4), and Goleta and Carpinteria sloughs (see also fig. 5). There are also a number of vernal pools in the Goleta area whose location and floral composition has been cataloged by the University of California at Santa Barbara.

As in other coastal counties, agricultural and urban developments, including energy facilities, are encroaching upon and destroying riparian systems. Several streams, such as Franklin and Santa Monica creeks in eastern Santa Barbara County, have been lined with concrete, resulting in the elimination of all riparian vegetation. Additionally, removal of native chaparral vegetation in the upper watersheds of Carpinteria and Goleta sloughs has resulted in an increased rate of sedimentation within these wetlands and their tributaries. Some Regional Commission and State Commission experiences dealing with threats to riparian resources in Santa Barbara County are presented below.

Permits

Union Oil of California .—The applicant proposed to drill 125 oil wells from multiple well sites and to install appurtenant facilities, including pipelines, storage tanks, and roads on land encompassing existing agricultural fields and portions of the Guadalupe Dunes and Santa Maria River mouth in San Luis Obispo and Santa Barbara counties.^[11] The drilling sites would have affected both riparian vegetation and pocket wetlands adjacent to the Santa Maria River. The Regional Commission determined that the development had the potential for causing a serious oil spill, as well as converting an existing degraded

[11] South Central Coast Regional Commission. 1981. Application and permit 314-09: Union Oil of California. On file with the South Central Coast District Office, Santa Barbara, Calif.

Figure 4.
Lower reaches and upper lagoon of the Santa Maria River,
border between San Luis Obispo and Santa Barbara counties.

wetland with associated riparian vegetation to an industrial use.

To avoid or mitigate these impacts, the Regional Commission required the applicant, prior to issuance of the permit, to offer for dedication a habitat protection easement over 32 ha. (80 ac.) of riparian vegetation and freshwater marsh. The agency (public or private) accepting the dedication was required to submit a habitat protection plan acceptable to the Regional Commission. In addition to this dedication, Union Oil was required to:

1) relocate wells outside the Santa Maria River riparian zone;

2) submit plans for the storage facilities, which were required to be set back from the creek to minimize biological impacts, the setback requirements to be determined in consultation with DFG;

3) develop, in consultation with DFG, plans for a proposed creek crossing which minimize biological impacts to the creek and surrounding area;

4) minimize the impact of the development on riparian vegetation by removing as little as possible during construction, submitting and carrying out a revegetation plan to restore the vegetation to its previous native state, and monitoring the area (using a qualified biologist) to assess the progress of the revegetation effort.

A feature of particular note in the Regional Commission's decision was the habitat easement which was designed to run the life of the oildrilling operations. The limited easement condition was applied because mitigation conditions could only be imposed as long as potential or actual impacts associated with the permitted development were present. Since oil developments are by their nature dependent upon a finite resource and it was expected that the operation would terminate at some future date, the easement itself was designed to be limited to the life of the development. The easement could not, however, be removed until the oil-production operation had ceased, and the owner of the underlying land had petitioned the Regional Commission or its successor and the third party holding the easement for reconveyance of the areas covered by the easement, based upon the following stipulations: 1) all oil and gas facilities permitted under the permit were removed; and 2) all landforms were returned to grades existing at the time of the original issuance of the permit. In the interim, the landowner and applicant would be bound by a legal responsibility endorsed by a third party who had a vested interest in protecting the sensitive habitats.

Figure 5.
Soloman Creek, Santa Barbara County.

Edgewood Estates .—The applicant proposed to divide 65 ha. (161 ac.) into nine lots for the purpose of developing eight detached single-family residences.^[12] The original parcel consisted of rolling hills traversed by a small coastal stream. The stream was bordered by 10 ha. (25 ac.) of riparian oak woodland consisting of sycamore, coast live oak, and several introduced exotics.

The Regional Commission determined that future development of the sites could affect the riparian woodland and therefore required that a minimum building setback be established and a deed restriction be recorded for the 10 ha. portion of the parcel containing the riparian woodland. In addition, before the permit was issued the developer was required to submit a map, prepared by a qualified biologist, with boundaries of and location of a buffer around the riparian woodland and monarch butterfly habitat, and to prohibit all development within sensitive areas and the buffer. Once deeds to the lots were recorded, the development restriction was to run with the land and could only be excepted by way of a permit from the Regional Commission or its successor.

[12] South Central Coast Regional Commission 1981. Application and permit 315-12: Edgewood Estates. On file with the South Central coast District Office, Santa Barbara, Calif.

In attempting to protect riparian vegetation in Santa Barbara County, the Regional Commission has employed two legal instruments not normally used to provide habitat protection: easement dedications and deed restrictions. Deed restrictions and easements can be applied to individual properties and be designed to run with the land (i.e, a change in ownership does not cancel any restrictions). If executed properly, these restrictions may provide more lasting protection of environmentally sensitive areas than traditional zoning designations which may be changed in accordance with shifting political conditions.

Habitat easement dedications can provide a particularly effective alternative means of protecting large tracts of lands containing habitat values, when the land is too expensive to be purchased outright. Despite the protection afforded by easement dedications, their effectiveness can be limited as a result of the following drawbacks:

1) execution of effective offer-to-dedicate documents requires a great deal of costly legal staff time;

2) the effectiveness of habitat easements depends in part on the cooperation of the underlying landowner and/or leaseholder, and the enforcement capability of the accepting party or regulatory agency;

3) courts may set aside habitat dedications and deed restrictions if it can be shown that there was a "taking" of land without providing the owner or leaseholder an adequate or reasonable use of the land at the time the legal restrictions were imposed; and

4) implementation of the habitat easement restrictions depends upon a public or private agency accepting the dedication and the responsibility for managing dedicated areas.

Deed restrictions have proven to be an effective means of protecting habitat values on smaller parcels located in more urbanized areas. Deed restrictions to developments within a riparian area offer the advantage over land-use designation, which is subject to change, of longterm protection which runs with the title of the land; their principal limitation is that their enforcement is dependent upon the availability of staff time and the initiative of the regulatory agency enforcing the restrictions.

Despite these shortcomings, the Regional Commission has found that few other methods, short of outright public ownership, protect large or medium-sized environmentally sensitive areas, such as riparian systems, as effectively over the long-term as easement dedications and deed restrictions.

Local Coastal Plans

Within Santa Barbara County, LCPs are being or have been prepared by the cities of Santa Barbara and Carpinteria and by the county for their respective jurisdictions. At the time of this writing, only Carpinteria had had its complete LCP certified. The following presents a summary of the riparian protection policies which have been proposed and/or certified by the Regional Commission and the State Commission.

Santa Barbara .—The principal riparian resources within the jurisdiction of the city of Santa Barbara are found along Arroyo Burro, Mission, and Sycamore creeks (Santa Barbara 1981). The State Commission certified the city's Land Use Plan (excepting the airport segment) with policies which are to supplement the policies of the city's existing General Plan Conservation Element. Several of the policies are summarized below.

Policy 6.8 states that the riparian resources, biological productivity, and water quality of the city's Coastal Zone creeks "shall be maintained, preserved, enhanced, and where feasible, restored." The use of reclaimed waste water to enhance creek flow is suggested. The city is to attempt to fund projects: to purchase the Coastal Zone section of Arroyo Burro Creek, to be retained in its natural state upon acquisition; to restore, enhance, and maintain Coastal Zone sections of the city's creeks; and to restore, enhance, and maintain the Andree Clark Bird Refuge.

Policy 6.9 requires the city to support programs, plans, and policies of governmental agencies to further best management practices in the city's watersheds and urban areas. Policy 6.10 establishes the requirements for setback buffers for native vegetation between the bank top and any proposed development. Policy 6.11 outlines procedures for and limitations on channelizations, dams, and other substantial alterations to watercourses.

In addition to the creeks within the contiguous portion of the city of Santa Barbara, Tecolote and Los Caneros creeks, which discharge into the Goleta Slough, are under the jurisdiction of the city. These creeks and the slough will be treated in a separate airport segment of the city's LCP. There are a number of policies proposed in the draft airport segment which relate to the portion of Goleta Slough and its tributary streams which are within the Coastal Zone. Notable among these policies are:

1) Policy C-2, which requires cooperation between the city and the Goleta Valley Mosquito Abatement District to limit mosquito abatement practices to the minimum, in an effort to protect wildlife, including the endangered Light-footed Clapper Rail and Belding's Savannah Sparrow;

2) Policy C-3, which forbids grazing and all other agricultural practices within the slough; and

3) Policy C-6, which requires the maintenance of tidal action to support optimum populations of marine organisms.

There are also a number of policies and proposed actions relating to future development of the airport and its effect upon the slough and its stream tributaries.

The proposed land-use policies for the airport segment of the city's LCP have not been reviewed by the State Commission at the time of this writing; however, a staff-level review of these policies has identified a number of elements which conflict with the requirements of the Act's protection policies. Specifically, the policies do not limit the removal of riparian vegetation from the tributaries to Goleta Slough; ongoing flood control operations which have resulted in the periodic clearing of channels for the purpose of maintaining floodflow capacities would be allowed to continue. Also, the possible realignment of creek channels to accommodate expansion or modification of the existing airport facilities would be permitted, in conflict with Act requirements.

Carpinteria .—The principal riparian resources within the jurisdiction of Carpinteria are located along Santa Monica, Franklin, and Carpinteria creeks (fig. 6) (Carpinteria 1980). Policies for protecting riparian and stream systems have been certified by the State Commission as part of the city's LCP Land Use Plan. Several of these policies are summarized below.

Figure 6.
Franklin Creek, Santa Barbara County.

Policy 9.15 establishes the standards for and methods of determining the size of streamside buffer strips. Policy 9.16 prohibits structures within the stream corridor and lists exceptions to the prohibition, including structures whose primary function is improvement of fish and/or wildlife habitat and flood control structures. Policy 9.19 forbids "cultivated agriculture and the installation of septic tanks" within the stream corridor. And Policy 9.20 limits stream channelization or other major alteration to those projects presently approved and/or funded.

With the exception of Carpinteria Creek, the other major creeks within the city's portion of the Coastal Zone have been channelized; the remaining undisturbed portion of Carpinteria Creek within the city's portion of the Coastal Zone is scheduled to be acquired by the California Department of Parks and Recreation.

Santa Barbara County .—As with San Luis Obispo County, Santa Barbara County has jurisdiction over most of the riparian resources within the county's Coastal Zone. The most important resources are found along 105 km. (65 mi.) of streams, primarily situated on rural or undeveloped land in the northern portion of the county, north of the unincorporated community of Goleta. The county's resource protection policies will therefore play a major role in the preservation of its riparian systems within the Coastal Zone. The Land Use Plan of the county's LCP has been certified by the State Commission. The policies affecting riparian systems are summarized below.

Policy 9.37 establishes the standards for minimum buffer strips for streams in rural and urban areas and the conditions whereby those minimum conditions can be altered. The buffer strip will be determined in consultation with DFG and the Regional Water Quality Control Board, to protect biological productivity and water quality of the stream. Riparian vegetation, regardless of its distance from the stream itself, is protected and included in the buffer, and provision for reestablishment of previously removed or disturbed vegetation is required.

Policy 9.42 limits developments within the stream corridor involving dredging, filling, and grading to those necessary for flood control, bridge construction, water supply projects, trail construction, and pipeline laying, when no alternate to the proposed development outside the stream corridor is feasible. Policy 9.44 forbids grazing, cultivated agriculture, pesticide application, and installation of septic tanks within the stream corridor.

Until the passage of AB 385 (Hannigan) in 1981, permitting authority was not transferred from the Regional Commission to the local jurisdiction until the certification of the entire LCP (land use element and implementing ordinances). Consequently, prior to its termination in July 1981, the Regional Commission had an opportunity to apply the county's land-use policies to specific developments. In both cases the Regional Commission utilized site-specific restrictions to implement the general resource protection policies summarized above. The county's Land Use Plan policies, however, do not specifically require

the use of such implementing techniques as habitat easements or deed restrictions to secure protection of riparian resources.

Ventura County

Setting and Issues

The coastline of Ventura County is approximately 66 km. (41 mi.) long. Within the Coastal Zone there are eight streams, with 21 km. (13 mi.) of riparian vegetation. The most important stands of riparian vegetation occur along the Ventura and Santa Clara rivers (fig. 7), Calleaguas Creek (fig. 8), and Big and Little Sycamore creeks draining the Santa Monica Mountains.

Riparian vegetation has been eliminated as a result of agricultural expansion on the floodplains of the Ventura and Santa Clara rivers, and urban encroachments, including residential developments, public works facilities, and recreational park developments. Flood control facilities, including levees, realigned channels, and concrete box channels, have also reduced the amount of riparian vegetation along watercourses.

Figure 7.
Lagoon and lower reaches of the Santa
Clara River, Ventura County.

As with San Luis Obispo County, the Regional Commission has had occasion to deal with some of the potential threats to riparian vegetation on a case-by-case basis through the permitting process. Some of these permit decisions are briefly discussed below.

Permits

Ventura County Flood Control District .—The Ventura County Flood Control District proposed widening the lower portion of Calleguas Creek (referred to as the Revlon Slough) which discharges into Mugu Lagoon (fig. 9); the Revlon Slough had been previously channelized between earthen levees.^[13] The proposed flood control project included excavating 178,000 cu. m. (233,000 cu. yd.) of sediment along a 1.2-km. (0.75-mi.) reach of the Revlon Slough, erecting a new levee on the east bank, and restructuring and enlarging the levee on the west bank to protect adjoining farm lands, the Point Mugu Naval Air Station, and the existing Highway 1 bridge above Mugu Lagoon.

The project also entailed the removal of a dense stand of riparian vegetation, including salt bush (Atriplex lentiformis ), which had been established in the Revlon Slough. Furthermore, the proposed periodic maintenance of the channel by the flood control agency would have prevented the re-establishment and maturation of the riparian vegetation after the initial disturbance from construction. While granting the

Figure 8.
Calleaguas Creek/Revlon Slough, Ventura County.

Figure 9.
Mugu Lagoon, Ventura County.

[13] South Central Coast Regional Commission. 1980. Application and permit 212–26: Ventura County Flood Control District. On file with the South Central Coast District Office, Santa Barbara, Calif.

permit to construct the proposed flood control facilities, the Regional Commission imposed conditions on the project which would alleviate the impacts on riparian vegetation stemming directly from the construction of the facilities and subsequent ongoing maintenance activities.

During construction, the Ventura County Flood Control District was required to maintain a pond, the width of the channel and outside the temporary construction dike, for wildlife feeding. When construction was completed, tidal action was to be returned to the the lower portion of the Revlon Slough. The flood control agency was required to revegetate the outer bank of the western levee using salt bush. The Regional Commission also limited the conditions under which maintenance activities could be undertaken, to reduce the adverse impacts of the maintenance procedures on the vegetation. Maintenance activities were prohibited from 15 July to 15 September to protect the Least Tern feeding in the area. The removal of any riparian vegetation from the channel was forbidden once the initial construction was completed; the use of herbicides to control the growth of vegetation in the channel was also prohibited.

Southern PacificRailroad .—The Southern Pacific Railroad had previously diverted the flow of the lower Ventura River below the Main Street bridge to allow the repair of a portion of a railroad bridge and abutment which had been damaged by floodflows.^[14] The Regional Commission granted an emergency permit for the rediversion of the base flow back into the natural low-flow channel, which was lined with riparian vegetation. The Regional Commission imposed several conditions to minimize disruption of the riparian vegetation and associated aquatic resources. 1) The work performed was to be limited to breaching the temporary gravel dike to the degree necessary to redivert the entire flow of the Ventura River back to its original (pre-project) channel on the west river bank. 2) The work was to be supervised by DFG. There was also a time limitation placed on the work.

Local Coastal Plans

Within Ventura County, LCPs are being prepared by the cities of San Buenaventura, Oxnard, and Port Hueneme and by the county for their respective jurisdictions. At the time of this writing, only the Port Hueneme LCP and the Harbor segment of the San Buenaventura LCP have been certified; the other LCPs are in various stages of completion and review. The approaches to protecting riparian systems taken by two of these jurisdictions are summarized below:

San Buenaventura .—The principal riparian resources within San Buenaventura are located along the west bank of the lower Ventura River (fig. 10) (San Buenaventura 1981). The State Commission certified the city's Land Use Plan with the several provisions regarding development adjacent to the Ventura River.

1) Environmentally sensitive areas are identified and located, and the requirements for buffer strips around these areas are established.

2) Uses allowed within the buffer areas are listed. No structures are permitted in these areas. Access to the beach from recreational developments on a specific property is limited, and fences and signs are required to restrict access to the buffer and sensitive areas.

3) A Ventura River floodway is defined, and uses permitted within the floodway, including passive recreation, education, and scientific research, are established.

4) A floodway fringe is established, and conditions under which development will be allowed in this area are listed. Developments may not degrade the environmentally sensitive areas or adversely affect flood control facilities.

Figure 10.
Lagoon and lower reaches of the
Ventura River, Ventura County.

5) "In order to protect the anadromous fish run in . . . and the biological productivity of the Ventura River lagoons and sensitive habitats, the City shall consider the effects of . . . its actions . . . in order to assure the maintenance of adequate flows within the river to maintain instream flows as well as stream productivity within the Coastal Zone. Developments shall not adversely impact the water supply, groundwater levels, or water quality of the river within the Coastal Zone."

Oxnard .—The east bank of the Santa Clara River and Magrath Lake contain the most significant riparian resources within Oxnard's portion of the Coastal Zone (Oxnard 1981). The mouth of the Santa Clara River and portions of Magrath

[14] South Central Coast Regional Commission. 1978. Application and permit 168–22: Southern Pacific Railroad Company. On file with the South Central Coast District Office, Santa Barbara, Calif.

Lake have been incorporated into Magrath Beach State Park. Both of these areas have been designated natural preserves within the State Park System. The general policies summarized below regarding development adjacent to environmentally sensitive areas have been certified by the State Commission as part of Oxnard's LCP Land Use Plan:

1) New development adjacent to sensitive or resource protection areas must be sited and designed to mitigate any adverse impacts to the wetlands. Resource protection areas are protected by a buffer strip 30 m. (100 ft.) wide, although the buffer can be reduced in width if an applicant can demonstrate that a larger buffer is unnecessary.

2) No use may significantly disrupt the habitat values of the sensitive areas.

3) Any proposed development within 30 m. (100 ft.) of a sensitive or resource protection area must be accompanied by an assessment by a qualified biologist of the area's resources, any potential impact from the development, and proposed mitigation measures.

4) Evaluations and recommendations of use adjacent to these areas will be made in cooperation with DFG.

5) Restoration of damaged habitat areas may be a condition of permit approval.

Summary

The Commission permit decisions and LCP policies presented in this paper will serve as the principal guides to local governments along the South Central Coast in their efforts to preserve, and where feasible, restore their diminishing coastal riparian resources. It should be recognized, however, that in many cases other public agencies with regulatory powers, such as DFG, the US Army Corps of Engineers, the Regional Water Quality Control Boards, and the State Water Resources Control Board will also share the responsibility of protecting threatened riparian resources.

Conclusions

The South Central Coast Region contains significant riparian resources distributed along a large number of short coastal rivers and streams. Disturbance and destruction of riparian systems have been most extensive along the lower reaches of these coastal watercourses where residential, industrial, recreational, and agricultural development (and their related flood control facilities) have been most intensive. This is the result of the equable climate, fertile soils, and recreational opportunities found along the coast.

The strong resource protection policies of the Act have provided a legal basis for regulating development which adversely impacts riparian vegetation. During its five-year tenure under the Act, the South Central Coast Regional Commission has on numerous occasions exercised its authority to modify proposed projects in order to alleviate or eliminate their potential adverse impacts on selected riparian systems. In doing so, a wide variety of techniques have been employed. Some of the most effective have been site relocation, setbacks or buffers, special construction techniques, offers-to-dedicate, and deed restrictions.

A review of the Regional Commission's overall record in dealing with riparian resources indicates, however, that the policies of the Act have not always been applied with equal rigor. As a result, projects have been permitted which have either directly or indirectly damaged or eliminated coastal riparian vegetation. There are many reasons for the uneven application of the resource protection policies of the Act, but perhaps the most important have been the imposition of local political pressures (or the lack of active political support) and the changing composition of the Regional Commission membership over its five-year life.

Despite inconsistencies in the application of the resource protection policies of the Act relating to riparian vegetation, the permit history of the Regional Commission provides an important example and guide to local governments preparing LCPs based upon the policies of Chapter 3 of the Act. LCPs prepared to date reflect this permit history in many land-use policies. However, many LCP policies have built in, either as a matter of necessity or expediency, language which allows a wide latitude for interpretation. The presence of such terms (e.g., "wherever feasible," the non-mandatory "may") can be used to undermine initial declarations of intent.

Perhaps more importantly, the decisions of local jurisdictions will be influenced by the composition of individual boards of supervisors or city councils and local political exigencies. The element of a strong statewide perspective which was brought to the decision-making process by selecting Commissioners from a broad spectrum of local and general public interests will not be replicated at the local level. To a greater degree, the preservation of riparian vegetation will depend upon the effectiveness of local constituencies to influence the local political process. The future of riparian vegetation under this new, or more accurately, re-established regulatory arrangement remains uncertain.

Author's Update

Since the initial preparation of this paper (in September 1981), California has undergone a change of administrations which has had, and will continue to have, a profound effect on the state's coastal management program.

The newly elected Governor made the abolition of the Coastal Commission a highly visible plank in his campaign platform. While the direct elimination the the Commission has not been possible because of its initial authorization by the California Legislature, the Governor has exercised other constitutional prerogatives in expressing his fundamental opposition to the Commission and the resource protection policies embodied in the Coastal Act of 1976. Most important have been his control over the Commission's budget and the appointment of Commission members.

The Commission's 1983–84 budget, as approved by the legislature, has been reduced by the Governor from $7.8 million to $6.4 million. This new budget is $3 million less than the previous year's budget, a reduction of 32%. Of the $1.4 million cut from the budget by the Governor, over half (or $782,000) was federal matching Coastal Zone management funds—this money does not represent a savings to the state. The most direct impact of the reduced budget is a reduction in the number of staff positions, from 171 authorized in 1982–83, to 115 for fiscal year 1983–84. Many of these reductions will be made in critical areas such as the Commission's technical and legal services departments, which have in the past enabled the Commission to deal effectively in controversial situations.

The Governor's appointments to the Commission have also had a noticeable effect on the operation of the agency. New members appointed to the Commission have gone on record as opposing the Commission's charge and have actively opposed its basic positions on resource protection. Significantly, the Governor has replaced the highly respected representative of the DFG, who sat as an exofficio member and provided the Commission with technical advice on resource issues, with an individual with no resource management experience.

The changing composition of the Commission has been reflected in its decisions on resource issues, including the protection of riparian vegetation. In a recent action, for example, the Commission approved a major LCP which contained policies allowing the construction of roads in riparian corridors, with a minimum setback from the watercourse of only 25 ft. The decision ran counter to the Commission's previously established standard which required a minimum setback from the landward extent of any riparian vegetation of 100 ft., with only passive uses allowed within the buffer area.

Aside from the formal control exercised over the Commission's operations, the Governor has exercised his ability to substantially affect the climate in which the Commission and its staff operate. This includes applying pressure on individual Commission members, encouraging political and legal challenges to the Commission's decisions, directly intervening at the staff level in the professional review process, and endorsing legislation which would undermine the basic policies of the Act.

Some of the effects of these activities have already become apparent. For example, senior staff members have begun to leave the agency in significant numbers, thus depriving the agency of vital expertise and experience. Junior staff members have quickly learned that tough positions on resource issues may not receive support from supervisors or may be modified by the agency's managers for political reasons, without regard to technical or policy considerations.

While the basic policies of the Act remain in force as of this writing [August 1983], the enormously complex and time-consuming bureaucratic apparatus necessary to implement and enforce those policies is being effectively dismantled, if not completely abolished, in order to better conform to the political preferences of the new administration.

Literature Cited

Bailey, H.P. 1966. The climate of southern California. 87 p. University of California Press, Berkeley.

Barbour, M.G. and J. Major (ed.). 1977. Terrestrial vegetation of California. 1,002 p. John Wiley and Sons, New York, N.Y.

California Coastal Zone Conservation Commission. 1975. California coastal plan. 443 p. California Coastal Zone Conservation Commission, San Francisco.

California Coastal Commission. 1980. Biennial report, 1979–80. 32 p. California Coastal Commission, San Francisco.

California Coastal Commission. 1981. Statewide interpretive guideline for wetlands and other wet environmentally sensitive habitat areas. 46 p. California Coastal Commission, San Francisco.

Carpinteria. 1980. Local coastal program, land use plan and zoning ordinances. 97 p. City of Carpinteria, Carpinteria, Calif.

Dibblee, T.W., Jr. 1950. Geology of southwestern Santa Barbara County. Bulletin 150, California Division of Mines and Geology, San Francisco. 87 p.

Grover City. 1981. Local coastal program, land use plan and zoning ordinances. 381 p. City of Grover City, Grover City, Calif.

Hoover, R.F. 1970. The vascular plants of San Luis Obispo County, California. 350 p. University of California Press, Berkeley.

Latting, J. (ed.). 1976. Plant communities of southern California. Special Publication No. 2, California Native Plant Society, Berkeley, Calif. 164 p.

Mason, H.L. 1969. A flora of the marshes of California. 878 p. University of California Press, Berkeley.

Morro Bay. 1981. Local coastal plan, land use plan. 188 p. City of Morro Bay, Morro Bay, Calif.

Munz, P.H. 1974. A flora of southern California. 1,086 p. University of California Press, Berkeley.

Norris, R.M., and R.W. Webb. 1976. Geology of California. 365 p. John Wiley and Sons, New York, N.Y.

Oakeshott, G.B. 1978. California's changing landscapes: A guide to the geology of the state. 379 p. McGraw-Hill Book Company, New York, N.Y.

Oxnard. 1981. Local coastal program, land use plan. 89 p. City of Oxnard, Oxnard, Calif.

Pismo Beach. 1980. Local coastal plan, land use plan. 265 p. City of Pismo Beach, Pismo Beach, Calif.

San Buenaventura. 1981. Local coastal program, land use plan. 228 p. City of San Buenaventura, San Buenaventura, Calif.

San Luis Obispo County. 1981. Local coastal program, land use plan. 384 p. County of San Luis Obispo, San Luis Obispo, Calif.

Sands, Anne (ed.) 1977. Riparian forests in California: their ecology and conservation. Institute of Ecology Pub. No. 15, University of California, Davis. 122 p.

Santa Barbara. 1981. Local coastal program, land use plan: component 9 airport. 63 p. City of Santa Barbara, Santa Barbara, Calif.

Smith, C.F. 1976. A flora of the Santa Barbara region, California. 331 p. Santa Barbara Museum of Natural History, Santa Barbara, Calif.