Historical descriptions of Scott River and its streambanks reveal immense changes have occurred. Starting in the 1820s, fur trappers removed thousands of beaver from "Beaver Valley", particularly in the East Fork. A map of "Scott's Valley" from 1852 (Figure 1) identifies "beaver dams" in the Big Slough/Kidder Creek area of the valley, but no where else.
Gold miners arrived in Scott Bar in 1850 and soon spread up to sites around Scott Valley. Placer mining in the late 1800s, particularly in the South Fork and Oro Fino Creek, washed large portions of streambanks downstream. Mining ditches and flumes were built in every stream from the South Fork to Scott Bar. Huge mining dredges excavated gold from ancient river deposits in the floodplains and left extensive cobble-sized tailings piles in the upper Scott near Callahan, as well as McAdams Creek off of Moffett Creek. Sediment plumes from these dredges extended far downstream and impeded fish surveys by the state in June 1934. Many of these original mining ditches were eventually converted for irrigation purposes.
In 1934, a federal fishery biologist stated the problems of the Scott, for steelhead, were (in order of importance): 1) loss of fish through unscreened and inadequately screened irrigation ditches; 2) dams which ban access to spawning grounds; 3) temporary dams which interfere with downstream movement of young fish. In the upper river above Callahan, he reported that both spawning grounds and food had been destroyed by silt from mining (Taft, 1934). While west side streams were noted to have a "natural tendency to dry up in their lower courses where the water sinks into the gravel of the valley", the drying was "accentuated by the numerous diversions."
Much of Scott Valley's native vegetaton was gradually cleared for farming of crops and raising of livestock. Before the advent of powerful tractors, farmers disliked tall pine trees casting shadows over fields and keeping the soil frozen longer in the spring. A panoramic photo of the Scott at Horn Lane (County Museum) reveals a swath of riparian woodland and swales of marshy plants in about 1908. In the 1920s, large cottonwood along the Scott's banks were removed for firewood, fuel for steam tractors, and because of disease, according to oldtimers. In June 1934, the Scott River between Fort Jones and Shackleford Ck. was described in a state stream survey as having dense willows along the shore and good to excellent pools and shelter (CDFG, 1934).
A prolonged drought hit the region from 1923-1931, with the Scott River going completely dry in 1924 (Jim Denny, personal communication). Floods followed in the 1930s, and following one in the winter of 1937-38, Siskiyou County requested the U.S. Army Corps of Engineers to "clear the rivers throughout Scott Valley of debris from flooding". This work began in August 1938 (Etna Western Sentinel, 8/10/38). With their tractor blades and saws, they also removed the remaining riparian vegetation through the middle of the valley (Orel Lewis, pers. comm.). The Corps also built levees along the mid-Scott River (many of which are still in existence.) Aerial photos of the river from 1944 reveal little or no vegetation along Figure 1.the Scott River's banks.
In the first decades of the 20th century, the lower portion of the Scott Valley near the mouth of Oro Fino Creek was known as marshy ground popular for waterfowl hunting (Orel Lewis, personal communication). However, the wet soils impeded farming and "drainage control" assistance was sought from the government. While not yet documented, several sources relate that a "bedrock sill" in the lower Scott above Meamber Bridge was blasted down about 10 feet in the late 1930-early 1940s to improve drainage and lower the water table (Orel Lewis & Don Brazil, pers. comm.). If this major alteration did occur, the permanent effect on the ground water storage and riparian vegetation would be quite significant.
Following a series of damaging floods from 1940 to 1974, the Scott's channel through the valley was further changed. Earthen flood control levees were built along lower Etna, Kidder and Moffett Creeks. Designed by the U.S. Soil Conservation Service (now called the Natural Resource Conservation Service), permanent bank stabilization structures, were also tested, with large rock proving to be the most flood-proof. As a result, rock rip rap has been placed along much of the Scott and its tributaries to prevent loss of farmland (see Table 2).
FISH HABITAT FINDINGS
Habitat conditions for the spawning, rearing, and holding needs of salmon and steelhead vary widely within the watershed. Some streams or sections of streams affected by little or no development have habitat that is in good condition, such as some of the tributaries located in the canyon. At the other extreme are sites where both quality and quantity of the stream habitat are poor. Habitat conditions in the Scott River and some of its tributaries are not well documented. Questions needing answers are: Is rearing or spawning habitat limiting in the canyon? or is it a problem only in the valley and how important is it in the valley? If there were a self-sustaining fish population, is there enough habitat already? Where specifically are the limitations, what are the limitations, and how do they vary temporally?
Several reports have stated that rearing and spawning conditions for anadromous fish stocks in the Scott River system are affected by: excessive sediment, lack of water, high stream temperatures, and lack of instream cover (CDWR, 1965; CDFG, 1974; CH2MHill, 1985; West et al, 1991; KRBTF, 1991). These conditions are described below:
Sedimentation: A significant local fisheries problem is excessive sand-sized (<6.3 mm) sediment derived from highly erodible decomposed granitic (DG) soils located on the western slopes above Scott Valley (CH2M Hill, 1985). Excessive sediment causes problems for fish because it smothers eggs and aquatic invertebrates in spawning gravels, eliminates bottom cover, and reduces the size and number of pools. Scott Valley exemplifies a low gradient river system, dropping 264 feet in 29 miles, and is a natural area for sediment to deposit (Lewis, 1992).
One recent study identified accelerated DG erosion sources in the Scott to be roads (63% of total), upslope streambanks (23%), and logging skid trails (13%); certain sub-basins also produced more DG sediment than others (Sommarstrom et al, 1990). In one targeted sub-basin, solutions to cumulative granitic sediment problems are being developed and implemented by the French Creek Watershed Advisory Group, which is focusing on road management, fire and fuel management (for erosion prevention), and monitoring. Short-term monitoring results are showing significant reduction in sediment levels in fish rearing pools (Power, 1994). More information on the sedimentation issue can be found in the above referenced studies.
Lack of Streamflow: In prolonged droughts, large portions of the main stem Scott are completely dry (i.e., 1924, 1977, 1991, 1994). Low flows, occuring June to November in most years, are a common condition in the main stem Scott and some major tributaries. While some streams naturally dry up, these low flows are believed to significantly impact salmon and steelhead production. Reports have identified the dewatering of streams in the Scott system to be a problem (CDFG, 1974; West et al, 1990). Dewatering strands many thousands of juvenile salmon and steelhead each year, based on CDFG fish rescue records. Redds are also sometimes dewatered in the autumn when water levels rise and then subside as a result of rainfall patterns in conjunction with diversions (DesLaurier, 1993). The CRMP Water Action Plan is seeking to facilitate increased streamflows and reconnecting stream reaches, with an initial emphasis on fall flows.
Streamflow usually goes subsurface in the lower reaches of Etna, Patterson, Kidder (including Big Slough), Moffett, and Shackleford Creeks each summer through early fall. Most eastside drainages and gulches are considered ephemeral streams, only flowing temporarily during high rainfall periods. If these flows coincide with salmon and steelhead runs, spawning could occur but rearing would likely occur elsewhere.
Unscreened Diversions: Each year many salmon and steelhead juveniles and some adults enter unscreened agricultural diversions and are lost. While a focused fish screen program began for the Scott in 1938 (Figure 2), the effort to screen all ditches is not yet complete. Since the Scott River Adjudication in 1980, river pumps have been replaced with wells and only a very few remaining pumps are still entraining fish. A recent preliminary inventory of diversion ditches possibly affecting anadromous fish reveals an estimated 125 unscreened ditches (Sommarstrom, 1994). While field checking of these diversions is still needed, most will likely need screening. California law requires CDFG to screen and maintain diversions installed before 1972 which are less than 250 cubic feet per second (Fish & Game Code Sections 6020 et.seq.). All diversions in Scott Valley are smaller than this size and almost all were developed before 1972. To date, CDFG has screened 30 diversions throughout the Scott Valley's streams (R. Dotson, CDFG, pers. comm.). Under current budgetary and staffing constraints, CDFG's Yreka Screen Shop is only capable of building two new fish screens each year. In addition, daily and yearly maintenance practices are difficult to sustain by the Department, especially as more screens are added.
Fish screening efforts are currently being expedited through supplemental state grants to Etna High School for student-built screens (1-2 per year), private grants for local-built screens (1-2 /year), and new federal cost-share funds (ASCS, now CFSA) to landowners. Old screens may also need replacing, and alternative technologies to prevent fish losses need to be pursued (Odenweller, 1994). In addition, current screening practices need to be evaluated to determine if they are adequately protecting the fishery resources at screened diversion sites (i.e., are significant numbers of juvenile/adult fish being lost when screens are removed in the fall/winter.)
Fish passage structures: Fish ladders have been placed at permanent stream structures. In 1990, a ladder was built over the City of Etna's diversion dam on Etna Creek. Similar structures were also placed in the Scott over Young's Dam on the Scott River and over a Figure 2. Historic Accounts of Fish Screen Needs in Scott River Editorial, Western Sentinel Etna, Calif. March 9, 1938 "California Needs Fish Screens!" California Conservationist October 1939barrier in Thompkins Creek. Their effectiveness needs to be evaluated and any necessary improvements made.
Instream structures: When instream habitat is deficient, one strategy is to provide habitat structure artificially instead of waiting for it to naturally recover. The Klamath National Forest has experimented with instream structures for almost a decade, particularly in the Salmon River. The most cost-effective structure was digger logs, which were placed to simulate natural large woody debris and increase rearing habitat for juvenile fish (Olson & West, 1990). How necessary or effective similar structures would be in the Scott is not known. Preferred coho rearing locations are shallow, quiet areas usually associated with backwater pools, dam pools, and beaver ponds but are also found in side channels, along the margins of other types of habitats, and in glides and boulder-cobble riffles (Reeves et al, 1989). Coho are also usually found associated with heavy cover, such as overhanging banks and canopy, or woody debris and these types of sites are presently quite limited in the Scott system (D. Maria, CDFG, pers. comm.).
To help compensate for poor quality spawning habitat in the main stem Scott, the Kelsey Creek Spawning and Rearing Channel was built in 1985 by the Klamath National Forest and CDFG. It is designed to provide "near ideal" spawning conditions for 70-80 pair of chinook spawners, which should produce a maximum of 400 adult fish. While chinook, coho and steelhead have created redds in the channel, it does not yet support a self-sustaining return of any of these stocks (USFS, 1992).
Habitat Evaluation: Habitat typing is the standard evaluation method presently used to identify physical habitat limitations (McCain et al, 1990). Such information is critical to properly site and prioritize rehabilitation and restoration projects. An inventory of stream habitat conditions in the Scott drainage needs to be completed since only habitat within the canyon section and lower Shackleford Creek has been systematically evaluated to date (West et al, 1990).
Habitat Projects: As of 1994, many types of fish habitat and watershed improvement projects have been completed in the watershed. Table 2 summarizes the types, location, funding, and number of known projects funded by the California Dept. of Fish and Game, U.S. Fish and Wildlife Service (through Klamath Fisheries Restoration Program/Task Force), or landowner cost-shared through the California Farm Service Agency (CFSA, formerly ASCS). Many other fish habitat and watershed projects have also been completed on public and private lands, which are not included in Table 2.
Table 2. Inventory of Stream & Watershed Projects in the Scott River Watershed, 1957-19941.
Type of Project Location Project Funds Number of Projects Fish Screens Tribs $305,916 26 Fish Rearing Orleans $32,624 3 Streambank Main stem Scott $1,687,892 172 Protection / Tribs $1,532,676 137 Fencing (some) Fencing / Planting Main stem $53,110 3 Riparian Planting Main stem $12,117 1 Studies Main & Tribs $143,526 5 Education All $4,900 2 Fish Ladders Tribs $10,950 2 Sediment Removal Main $17,100 2 Instream Main & Tribs $36,681 4 Structures Spawning Channel Kelsey Ck. $147,5002 1 Monitoring Main & Trib $72,9933 1 TOTAL $4,057,985 359
A. FISH HABITAT OBJECTIVE: Improve and maintain instream fish habitat conditions. Evaluate habitat needs and prescribe habitat projects that are practical, cost-effective, and proven beneficial. Landowner approval will always be secured before implementing these tasks on private land. Landowners will be involved in all planning, access and evaluation.
1. Initial efforts to identify factors limiting spawning, migration and rearing (e.g. timing and distribution) will focus on the mainstem from Jones Beach upriver, the South Fork, the East Fork and French Creek.
2. Identify and prioritize sites with the greatest potential for improvement where conditions are currently limiting fish production (based on Task 1 above).
3. Design and complete projects to improve spawning, migration and rearing through improvement of conditions that limit anadromous salmonid production (based on #1 above).
a. Consider instream projects as appropriate.
b. Write up project proposal for grant funding.
c. Implement funded projects.
d. Evaluate effectiveness of projects, and adjust as necessary.
4. Prevent the loss of anadromous fish by stream diversions through a fish screening program:
a. Update the inventory of stream diversions with potential impact
on salmon and steelhead for level and status of use.
b. Evaluate if significant numbers of juvenile/adult fish being lost when existing screens are removed in the fall/winter.
c. Screen diversions based on the following priorities: 1) streams with species petitioned for listing; 2) highest abundance of juvenile fish; 3) start at bottom and move to top of stream; 4) largest diversions, depending on location.
d. Ensure that screens are adequately maintained (daily and long-term). Secure on-going funding to provide maintenance staff for assignment to the Scott River.
e. Seek new funding sources to expedite construction and placement of screens. Encourage locally built screens, including high school students.
f. Work with landowners, water users, CDFG, NRCS (SCS), and others to make the program successful. Encourage ditch users to participate in screen maintenance.
5. Evaluate effectiveness of existing fish passage structures in the Scott drainage basin and pursue any necessary improvements.
6. Encourage use of the Kelsey Creek Spawning Channel, following agreement on objectives and evaluation methodology (including genetics). Recommended uses include:
a. Research. Opportunities should be explored with colleges and
universities to study local salmonid life history, genetics, and habitat.
b. Education. Observing fish so easily in this location provides an exceptional educational tool for both school-age children and adults.
c. Natural Rearing. If the channel is artificially or naturally used by spawners, rearing should be done naturally and not artificially.