Watershed
sion. Reducing sediment from these sources can improve salmon and steelhead spawning habitat.
The Action Plan explains how gully erosion can alter watershed hydrology, reduce summer baseflows and also create sediment pollution problems. The ERRP has applied for an additional SCC Prop 1 grant to plan and permit structures to control gullies and other erosional features in lower Tenmile Creek and Cahto Creek.
There is a geologic fault running down the middle of the Tenmile Creek watershed from north to south that divides the Coast Range from the Central Belt Mélange Terrain, which gives rise to grasslands in the eastern part of the watershed. These areas are particularly susceptible to gully erosion if roads are constructed and downspouts from road drainage are not properly armored.
Water supply in tributaries of Streeter and Big Rock creeks, both pilot project sub-basins of interest, was compared to the control stream Elder Creek using modeling. Flow impairment in Streeter and Big Rock creeks appears to be driven by increased evapotranspiration of the second-growth forest, as well as Douglas fir trees overtopping oaks. Since oaks use less water than fir, this unwanted succession also decreases baseflows.
The ERRP is obtaining a forest health grant to begin work on this problem in cooperation with the Tenmile Creek Watershed Council, which has plans to focus on forest health and to bring in resources for implementation.
The ERRP discovered that there was a need to assist with obtaining water security for a large organic farm at Black Oak Ranch and at Camp Winnarainbow, which hosts economically disadvantaged innercity youth to learn about art and nature each year.
The ERRP has included planning and permitting for needed water storage for the farm and camp in a recent SCC Prop 1 phase two application, and a subsequent grant will be sought for implementation. The ultimate goal is to make it so both enterprises can forbear from summer water use of Streeter Creek in exchange for infrastructure that provides for their water needs and future water security.
The Action Plan defines a priority water conservation area in the western part of the Tenmile Creek basin, where partnerships with landowners who want additional water storage to enable forbearance will be sought. The report discusses groundwater issues, including the connection between surface water and groundwater, and points out potential conflicts that could arise in the future.
The fish community of Tenmile Creek is described in detail, with colorful photos of fish taken during the two year pilot project. The portrait of Tenmile Creek health that emerges from the report indicates signs of resilience, but also ecological stress. Water temperatures can be acutely warm for salmon and steelhead, especially in dry years. Reaches of main Tenmile Creek and many of its tributaries also become disconnected in dry years, whereas they were all formerly perennial. Hardy, warm water-adapted, native suckers are becoming rare. As the main branches of Tenmile Creek dry up in summer, water quality in isolated pools deteriorates, and non-native species proliferate.
Sufficient flows in the summer of 2019 allowed high survival of juvenile steelhead and early reconnaissance in 2020 indicates a good level of spawning. Basinwide, Eel River Chinook salmon are trending downward, but they sometimes spawn in the thousands in Tenmile Creek in years of high abundance like 2010-2012 and 20162017. Coho salmon are rare, but achieving our goal to restore perennial cold water habitat may help them to recolonize.
The ERRP will be accepting comments on the Action Plan for 30 days up until Wednesday, July 22 There will be a public presentation before July 31, if not prohibited by restrictions related to the pandemic. An announcement will be made. You may also call 707-223-7200 to find out more.
Copies of the Action Plan are available on- line at www.eelriverrecovery.org. and will be made available in hard copy at the Laytonville County Water District office. Call 707 223-7200 to request a copy.