| Marsh Creek | |
| Arroyo De Los Poblanos[1] | |
| stream | |
| Country | United States |
|---|---|
| State | California |
| Region | Contra Costa County |
| Tributaries | |
| - left | Briones Creek, Dry Creek, Deer Creek, Sand Creek |
| - right | Sycamore Creek, Kellogg Creek |
| Source | Eastern Mount Diablo in Morgan Territory Regional Preserve |
| - location | 12 mi (19 km) SSE of Clayton, California |
| - elevation | 2,360 ft (719 m) |
| - coordinates | [2] |
| Mouth | |
| - location | Sacramento – San Joaquin River Delta at Oakley, California |
| - elevation | 0 ft (0 m) [2] |
| - coordinates | [2] |
Marsh Creek is a stream in Contra Costa County, California in Northern California which flows 30 miles (48 km) to the Sacramento – San Joaquin River Delta at Oakley, California, in Contra Costa County.[3]
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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.[1]
The Marsh Creek watershed drains about 100 square miles 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 major tributaries are Briones, Dry, Deer and Sand Creeeks. Briones Creek, which drains the undeveloped Briones Valley, flows into Marsh Creek at the Marsh Creek Reservoir, while Dry, Deer, and Sand creeks all flow into Marsh Creek within the city limits of [[Brentwood, California|Brentwood].[4] 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 11 miles (18 km) from the outfall of the Marsh Creek Reservoir into the western Delta at the Big Break area of the Sacramento-San Joaquin River Delta northeast of the city of Oakley.[5]
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. Straightening of lower Marsh Creek for flood control steepened its gradient relative to its original meandering course, requiring construction of a six foot waterfall drop structure 7 miles (11 km) 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.[6] Below the dam and above the drop structure barrier there is suitable gravel quality, quantity, and vegetative cover to support Chinook salmon spawning. The presence of Rainbow trout (Oncorhyncus mykiss) has not been established in fish surveys of Marsh Creek above the drop structure.[7] In December 2010, construction of a $400,000 fish ladder made passage of the drop structure possible for the first time in 52 years, enabling chinook salmon and steelhead to potentially utilize the next 7 miles (11 km) of stream channel, up to the Marsh Creek 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.[8][9]
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 (rainbow trout are the landlocked form of steelhead trout). 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.[4]
The intermediate and upper watershed zones are also home to four federally listed faunal species – the Alameda Whipsnake (Masticophis lateralis), California red-legged frog (Rana aurora draytonii), San Joaquin Kit Fox (Vulpes macrotis mutica), and Vernal pool fairy shrimp (Branchinecta lynchi).[4]
The tidal waters at the mouth of Marsh Creek and Big Break provide habitat for the federally threatened Sacramento splittail (Pogonichthys macrolepidotus) and Delta smelt (Hypomesus transpacificus). Big Break, where Marsh Creek enters the Delta, is one of only three locations where adult splittail still congregate in large numbers.[4]