Study Sites

Little Black Rock Spring

Little Black Rock Spring is located in Inyo County, California, approximately 14.5 km. (9 mi.) north of Independence and 1.6 km. (1 mi.) east of US 395. Prior to groundwater pumping, the spring flowed from the base of a fractured basaltic lava flow down a hill to a basin containing several ponds. Percolation from the ponds was minimal because the natural water table was high, approximately 1.0–2.4 m. (3–8 ft.) below ground level [Lee 1912]. The aquifer that supplied the spring was assumed to supply a nearby well, #351, water from which was used to estimate the chemical properties of the natural spring water at Little Black Rock Spring.

Groundwater pumping began in the early 1970s to supply water to the Little Black Rock Springs Fish Hatchery, because the volume of spring water was declining. Soon after pumping began, the spring ceased to flow. Water was then supplied to the spring area by Black Rock Ditch (fig. 1) which received water from two sources. The major source was Division Creek, a system of concretelined ditches and natural channels which receives water from Scotty Spring at the base of the Sierras. The second source was water diverted from Goodale Creek. Black Rock Ditch received water from the creek only when the damming action above the ditch intake caused an overflow; this seldom occurred.

Black Rock Ditch (site 1 for water chemistry) was a natural channel roughly 3–5 m. (10–15 ft.) wide and 0.6–0.9 m. (2–3 ft.) deep; it was

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

[2] Deborah J. Perkins is Master's Candidate, California State University, San Diego. Bruce N. Carlsen received his B.S. from the University of California, Santa Barbara. Mike Fredstrom will receive his B.S. from California State University, Fullerton. Richard H. Miller is Master's Candidate, University of Utah, Salt Lake City. Cindy M. Rofer is Master's Candidate, Humboldt State University, Arcata, Calif. Gregory T. Ruggerone is Master's Candidate, University of Washington, Seattle. Carolyn S. Zimmerman is attending Arizona State University, Tempe.

Figure 1.
Black Rock Ditch which supplies water
to the Little Black Rock Spring area.

lined with willows and other woody and herbaceous plants. Water flowed from the channel to the main pond (site 3) through a 12-in. diameter pipe. The main pond averaged 15 cm. in depth, contained at least three species of green algae, and was surrounded by three-square rush (Scirpusamericanus ) and the cat-tail Typhadomingensis . A loose rock dam below the intake maintained a water level high enough to allow flow into the pipe. From the pipe, water flowed through a small channel and into the pond system (fig. 2). On occasion the rock dam deteriorated to the point that water could not reach the intake pipe. This situation occurred during our study and resulted in a significant drop in water level in the ponds from evaporation and percolation. During our study, the water table was measured at 11.3–11.5 m. (37–38 ft.) in a nearby observation well.

Figure 2.
Main pond and marsh area at Little Black Rock Spring
with Anemopsis  californica  in the immediate foreground.

Fish Springs Lake

Fish Springs is located 8 km. (5 mi.) south of Big Pine (Inyo County) and 0.4 km (0.25 mi.) west of US 395. It is the site of a fish hatchery run by the California Department of Fish and Game (DFG). Fish Springs Lake, the study site, is located several hundred meters south of the hatchery. The lake once occupied a depression below the face of a vesicular basaltic lava flow. Caliche deposits at the site suggest that the water level may have been 0.6–0.9 m. (2–3 ft.) deep at one time (fig. 3). Pumping at the fish hatchery was increased in 1971 to replace the dropping volume of spring flow. Flow from Fish Springs ceased in 1971 (Williams 1978), which corresponded with the increase in pumping at the hatchery. It is likely that the lake and the spring received water from the aquifer associated with the fractured lava flow. This source is not established due to lack of data at the study site. The lake has been noted as having water some years and being dry in others. The amount of water in recent years may be attributed to the accumulation of runoff.

Figure 3.
Fish Springs Lake, a dry bed covered with
dead reeds. Note caliche deposits on rocks.

The Springfield

The Springfield is located 2.4 km. (1.5 mi.) east of Independence. The topography is essentially flat with the exception of broad, shallow

Figure 4.
Rabbit-brush (Chrysothamnus  nauseosus ),
the dominant plant at the Springfield.

depressions. The spring area had been invaded by the desert shrub rabbit-brush (fig. 4). The five wells adjacent to the site pumped water from several different levels of a complex layering of sand, clay, and gravel. The deepest well pumped from 143 m. (468 ft.). Another well had artesian flow until 1971, after which the depth was approximately 4.6–7.6 m. (15–25 ft.). Pumping began in the early 1900s, which made this area the study site with the longest pumping history. A brush fire passed through the area in 1971 and destroyed most trees and marsh vegetation.

Fish Slough

Fish Slough is located 8 km. (5 mi.) north of Bishop in the southernmost extension of the volcanic tablelands. The slough is a marsh and pond area that extends 6.4 km. (4 mi.) back toward Bishop and empties into the Owens River. There are three primary springs within the slough, the northernmost of which is site 1. This spring issues near the base of a steep slope of volcanic tuff inside a circular pool constructed of rocks and cement. Overflow continues south through a system of channels and ponds into which the other springs flow. Site 3 was a pond located 4 km. (2.4 mi.) south of site 1. The pond was surrounded by three-square rush, and the bottom covered with a thick mat of macrophytes. The slough is bounded on the east by a faulted block of Bishop Tuff. Spring flow at the slough might have been caused by the impoundment of water from the drainage basin at the fault adjacent to it. If this was the case, then agricultural drainage and precipitation in the basin were major sources of spring flow at the slough.

Collins Warm Springs

Collins Warm Springs is located 13 km. (8 mi.) north of Big Pine and 8.6 km. (5.5 mi.) east of US 395 at the base of the Inyo/White Mountains. It has been designated part of the Owens Valley Pupfish Sanctuary. Springs issue from several sources at the base of a weathered and fractured marble outcrop that was probably exposed by faulting. The main group of springs (site 1) flows into a man-made pond (site 2), which was dammed to support the pupfish population. The pond was 0.9 m. (3 ft.) deep, and the bottom was partially covered with Oscillatoria sp. Water flowed from the pond through a pipe down to an extensive marsh area. Except for the building of the dam, the area had been undisturbed for some time.