Martinez Dam


Martinez Dam

Climatology: Martinez has a climate typical of the coastal areas of southern and central California. Mean annual precipitation is about 18.00 inches, more than 95 percent of which fall during the cool season, from October to April. Summers are nearly rainless. Thunderstorms occur about two times per year based on records from San Francisco and Oakland.

There is no preferred season for-thunderstorm occurrence. In the cool season, thunder is sometimes associated with convective activity imbedded in general rainstorms. In summer occasional intrusions of cold unstable air aloft or moist tropical air at low levels over California create conditions favorable for thunderstorm development. the chances of one of these intense summer storms affecting a specific area in any given year, however, are very small.

Martinez Reservoir is impounded in a small, north facing valley at the eastern edge of the City of Martinez. The site is situated on the northeast margin of the East Bay hills which are, in the immediate reservoir vicinity, rounded low hills rising to elevations of 200 feet or less. To the west and south, the topographic relief increases to 600 feet or more along prominent ridges and hills underlain by folded Tertiary and Cretaceous strata which strike generally NW-SE. Approximately 2 miles north of the reservoir, the Sacramento River flows westward from Suisun Bay through the Carquinez straight. East of the site, the hills decrease in size and are, for the most part, buried beneath alluvial deposits which extend along the southern margin of Suisun Bay.

At the reservoir site, the hills are underlain by moderately hard Tertiary sandstone and minor shale, commonly mantled by thin alluvial cover. The bedrock strata dip moderately to the southwest of the reservoir. Minor, discontinuous faults locally cut the bedrock, but so not significantly disrupt the overall northwest tending synclinal structure. Throughout the site vicinity, alluvium, stream channel deposits, and artificial fill apron the hills and underlie the lower ground.

There are no recreational facilities available at this time

RegionFacilities in Mid-Pacific | Mid-Pacific Home Page
CountyContra Costa
Dam Type
WatercourseOffstream storage
Original Construction1946-1947
Modified Construction
National ID NumberCA10168
Hydrologic Unit Code

Structural Height62.0 ft
Hydraulic Height (Normal Operating Depth at Dam)42.0 ft
Top Parapet (Elevation)
Spillway Crest Elevation66.0 ft
Crest Elevation72.0 ft
Crest Length1200.0 ft
Crest Width
Base Width
Volume of Dam Construction Materials
Streambed at Dam Axis24.0 ft
Top of Exclusive Flood Control Pool (Elevation)
Top of Joint Use Pool (Elevation)
Top of Active Conservation Pool (Elevation)66.0 ft
Top of Inactive Conservation Pool (Elevation)35.0 ft
Top of Dead Storage Pool (Elevation)35.0 ft

Hydraulics & Hydrology
Total Water Storage at Elevation
Maximum Water Surface Elevation
Normal Water Surface Elevation66.0 ft
Spillway Type
Auxiliary SpillwayNo
Spillway Capacity at Elevation53 cfs at 67.9 ft
Auxiliary Spillway Capacity at Elevation
Uncontrolled Spillway Capacity at Elevation
Outlet Works Capacity at Elevation
Diversion Capacity at Elevation
Drainage Area40.0 sq mi
Hydrometeorological Report (HMR)HMR 49
Probable Maximum Flood (PMF) Report

Contact Information
TitleArea Office Manager
OrganizationSouth-Central California Area Office
Address1243 "N" Street
CityFresno, CA 93721-1813
Phone (Office)559-487-5116
OrganizationContra Costa Water District
AddressPO Box H20
CityConcord, CA 94524
Phone (Fax)925-688-8000
Phone (Office)925-688-8122

Last updated: Jun 04, 2009