Southern Steelhead Resources Evaluation Identifying Promising Locations for Steelhead Restoration in Watersheds South of the Golden Gate APPENDIX Gordon S. Becker Katherine M. Smetak David A. Asbury Center for Ecosystem Management and Restoration This appendix accompanies the Southern Steelhead Resources Evaluation1, in which rearing habitat related information was used to identify areas with high potential for steelhead production in watersheds south of the Golden Gate. The following narrative describes the basis for our estimates of stream miles of suitable rearing habitat in watersheds with reproducing O. mykiss populations. 1 Becker, G.S., K.M. Smetak, and D.A. Asbury. 2010. Southern Steelhead Resources Evaluation: Identifying Promising Locations for Steelhead Restoration in Watersheds South of the Golden Gate. Cartography by D.A. Asbury. Center for Ecosystem Management and Restoration. Oakland, CA. Table of Contents San Mateo County ............................................................................................................................................. 1 Santa Cruz County ........................................................................................................................................... 19 Monterey County ............................................................................................................................................. 53 San Luis Obispo County ................................................................................................................................. 81 Santa Barbara County ...................................................................................................................................... 99 Ventura County ............................................................................................................................................. 127 Los Angeles County ..................................................................................................................................... 137 Orange County .............................................................................................................................................. 147 San Diego County ......................................................................................................................................... 157 i San Mateo County San Pedro Creek San Pedro Creek During snorkel surveys conducted between May and September of 1989 in San Pedro Creek, high densities of O. mykiss were observed throughout the surveyed reaches. Fry numbers peaked during July surveys, in which 544 YOY, 347 age 1+, and 39 age 2+ O. mykiss were counted between the mouth and the Peralta Road Bridge and 541 YOY, 19 age 1+, and three age 2+ O. mykiss were counted in a reach extending 850 feet upstream from the Adobe Road Bridge (Sullivan 1990). According to a 1997 USDS study, San Pedro Creek “…supports the most viable steelhead trout population in San Mateo County… Juvenile age class diversity indicates year-round juvenile use... Though difficult to estimate, the adult spawning run may average between 150-300 adults in recent times” (USFWS 1997 p.7). In 2002, consultants collected 212 YOY and 17 age 1+ O. mykiss from a 6,634 foot reach of the lower mainstem and 225 YOY and 27 age 1+ O. mykiss from a 3,737 foot reach of the upper mainstem of San Pedro Creek (HES 2002). According to the report, “The mainstem provides the best conditions for rearing steelhead to smolt size and for supporting non-anadromous life histories, however, steelhead using the mainstem are more vulnerable to potential water quality degradation, siltation, sedimentation, and disturbance than those in the Middle Fork” (HES 2002, p. 1). Partial migration barriers were identified at the Linda Mar Bridge, Oddstad Bridge, and Adobe Road Bridge culverts during the 2002 survey (HES 2002). According to the San Pedro Creek Watershed Coalition website, plans to modify the barriers are being developed. A project to improve fish passage and reduce streambank erosion at the Capistrano Road crossing was completed in 2005. Middle Fork San Pedro Creek In 2002, consultants collected 203 YOY and five age 1+ O. mykiss from a 4,816 foot reach of the Middle Fork San Pedro above the South Fork confluence and eight YOY and one age 1+ O. mykiss from a 411 foot reach of the upper Middle Fork (HES 2002). The survey report states, “Steelhead spawning in the Middle Fork have the potential to saturate the available habitat with fry and produce a surplus that would eventually take up residence in downstream reaches” (HES 2002, p. 42). Denniston Creek Denniston Creek A 1953 DFG stream survey notes that Denniston Creek has approximately “3 miles of fishable water” (DFG 1953). Staff from DFG surveyed Denniston Creek from Highway 1 to approximately three miles upstream and observed “Numerous rainbow trout/steelhead” ranging from 4 to 6 inches in length in pool habitat “throughout the drainage” (DFG 1992). Two impassible barriers were noted, including a dam at approximately stream mile 1.2 and a culvert 0.5 miles upstream from the dam (DFG 1992). 1 In 2006 DFG staff observed 20 O. mykiss fry above the Highway 1 Bridge crossing in Denniston Creek and four age 1+ O. mykiss in pools located between Highway 1 and the impassible dam at stream mile 1.2 (DFG 2006). A 2004 fish passage evaluation identified the Prospect Way crossing as a severe passage barrier and assigned it a high priority ranking for modification (Taylor 2004). A draft implementation plan for priority restoration projects in San Mateo County streams indicates that funding will be sought to improve fish passage at Prospect Way barrier (Fish Net 4C 2008). Frenchman’s Creek Frenchman’s Creek In 2006, DFG staff conducted fish sampling immediately upstream and downstream of a flashboard dam on Frenchman’s Creek near 840 Frenchman’s Road. Sampling yielded 30 O. mykiss ranging from 20 to 194 mm FL in the 141.4 foot reach upstream of the dam and 14 O. mykiss ranging from 40 to 134 mm FL in the 114.4 foot reach downstream of the dam (Atkinson 2006). A 2006 Coastal Conservancy recommendation regarding restoration work on Frenchman’s Creek indicated that two miles of high quality rearing habitat existed upstream of a total passage barrier created by an earthen bridge and perched culvert at stream mile 2.0 (CCC 2006a). Barrier removal and stream restoration was recently completed at the site, providing steelhead access up to the natural limit of anadromy at a waterfall located approximately four miles from the mouth. Locks Creek A DFG stream inventory from the 1960s characterizes the fishery resources of Locks Creek as “good,” providing “winter flow and some steelhead spawning” (DFG ca 1965). Pilarcitos Creek Pilarcitos Creek Consultants conducted habitat surveys downstream and upstream of Stone Dam in 2004. Stone Dam is located on San Francisco Public Utilities Commission (SFPUC) property and creates a total barrier to fish passage. During the 2004 survey rearing habitat in the reach extending from Stone Dam downstream 2.7 miles was observed to be “limited by substrate composition, pool abundance, and flow” (Entrix 2006, p. 4-3). A culvert at stream mile 10.7 was identified as a low-flow barrier. The survey report notes that during electrofishing surveys conducted in this reach in 1995 and 1996, O. mykiss density averaged 29 YOY and 14 age 1+ individuals per 100 feet of stream. Between the upper margin of Stone Dam Reservoir and Pilarcitos Dam, rearing habitat was noted to be “similar to or somewhat better in quality than that in the lower reach” (Entrix 2006, p. 3-2). A culvert at stream mile 7.1 was identified as a potential barrier at high flows. As part of the 2004 survey, fish sampling was conducted at three sites within the upper reach, yielding a total of 89 O. mykiss. Multiple age classes were observed. A 2008 management plan for the Pilarcitos Creek watershed characterizes steelhead habitat conditions in the Pilarcitos Creek mainstem and tributaries. Rearing habitat in Pilarcitos Creek is characterized as “poor” to “poor-fair” in the reach between the mouth and Corinda Los Trancos 2 Creek, “fair” in the reach between Corinda Los Trancos Creek and Highway 92, “fair-good from Highway 92 to Stone Dam, and “fair” from Stone Dam to Pilarcitos Lake (PWA 2008). According to the report, CalTrans plans to modify a partial barrier on Pilarcitos Creek at the Highway 92 crossing. The report notes that a feasibility study for the installation of fish passage facilities at Stone Dam was conducted in 2006 (PWA 2008). Arroyo Leon Creek Researchers conducted fish sampling on the reservoirs of two seasonal dams on Arroyo Leon Creek in 2001. A total of 477 O. mykiss were caught in the basins of the two reservoirs, the majority of which were YOY and age 1+ (Smith 2001). Upstream of the upper reservoir, 50 YOY, 14 age 1+, and one age 2+ O. mykiss were captured. According to the survey report, “less than 35 smolts are likely to be produced from approximately 0.1 mile of sampled stream” (p. 4). A 2008 management plan for the Pilarcitos Creek watershed notes that the seasonal reservoirs on Arroyo Leon Creek have not been operated since 2001 due to regulatory restrictions related to the negative impact the timing of closure at the reservoirs had on smolt passage. The report states, “… the two ponds on Arroyo Leon provided, and still potentially could provide, the only “good” or better rearing habitat for juvenile steelhead” (PWA 2008, p. 48). The report characterizes