Marsh Creek (California)

The creek bears the name of notable California pioneer John Marsh who built his home on the creek in 1838 after acquiring the Rancho Los Meganos Mexican land grant from Jose Noriega on the western edge of the town of Brentwood and just to the east of what is now Clayton, California. Marsh Creek was originally named Arroyo De Los Poblanos. ==Watershed==

The Marsh Creek watershed drains about of the eastern slopes of Mt. Diablo and the neighboring portions of the Black Hills. Its upper tributaries are intermittent and small perennial streams which flow northwesterly until the creek turns east at Marsh Creek Springs. The creek was dammed downstream from the Springs in the 1960s, forming Marsh Creek Reservoir. The dam is south of Brentwood and north of the intersection of Marsh Creek Road and Camino Diablo Road. Major tributaries are Briones, Dry, Deer and Sand Creeks. Briones Creek, which drains the undeveloped Briones Valley, flows into Marsh Creek at Marsh Creek Reservoir, which lies in Marsh Creek State Park (California). Dry, Deer, and Sand creeks all flow into Marsh Creek within the city limits of Brentwood. The creek is largely channelized in the lower watershed, and includes a drop structure near the city of Brentwood that appears to be a complete passage barrier. The lower stretch of the creek includes from the outfall of the Marsh Creek Reservoir into the western Delta at the Big Break Regional Shoreline area of the Sacramento–San Joaquin River Delta northeast of the city of Oakley. ==Conservation and ecology==

Human activities have led to the loss of over 80 percent of suitable spawning habitat for fall-run Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento and San Joaquin River watersheds. There are archeological records of Chinook salmon at CCO-18, a site dating to 1000-1500 C.E. in the John Marsh State Historic Park in the Marsh Creek watershed. Straightening of lower Marsh Creek for flood control steepened its gradient relative to its original meandering course, requiring construction of a waterfall drop structure in 1958 below Marsh Creek Dam (4 miles from the creek mouth). The drop structure and the Marsh Creek Reservoir dam (constructed in 1963) are complete barriers to anadromous fish migration. Below the dam and above the drop structure barrier, there is approximately suitable gravel quality, quantity, and vegetative cover to support Chinook salmon spawning. The presence of coastal rainbow trout (Oncorhynchus mykiss irideus) has not been established in fish surveys of Marsh Creek above the drop structure. In December 2010, American Rivers, the Natural Heritage Institute and the Contra Costa Water District (CCWD), constructed a $400,000 fish ladder that made passage of the drop structure possible for the first time in 52 years, enabling Chinook salmon and steelhead to potentially use the next of stream channel, up to the Marsh Creek Reservoir Dam, as well as the Sand Creek and Deer Creek tributaries. The Friends of Marsh Creek Watershed citizen salmon monitoring program had identified salmon congregating immediately below the drop structure barrier prior to construction of the fish ladder. On December 2, 2012, Chinook salmon were videotaped above the fish ladder between Balfour and Central Avenue. By December 2016, Chinook salmon numbering in the hundreds used the fish ladder and returned to Marsh Creek to spawn. Numerous perennial pools in the intermediate and upper zones of the Marsh Creek watershed have been rumored to support rainbow trout (Oncorhynchus mykiss), however this has not been confirmed by fish sampling studies. If rainbow trout were identified in the higher watershed it would raise the possibility that steelhead trout historically used Marsh Creek for spawning. Recent observations of perennial pools in the upper reach of Sand Creek in Black Diamond Mines Regional Preserve suggest that removal of the two existing migration barriers on Sand Creek might open up suitable habitat for steelhead trout. ==Marsh Creek Regional Trail==

Marsh Creek Regional Trail is a recreational trail along Marsh Creek. It connects Creekside Park, a city park in Brentwood, with Big Break Regional Shoreline in Oakley. The trail is designed for hiking and bicycling. Most of the trail is paved and designated as multi-use. It is managed by the East Bay Regional Park District (EBRPD) and is approximately long. There are plans for extending the trail from Brentwood to Morgan Territory Regional Preserve and Round Valley Regional Preserve, making the total length . ==See also==