The 660-square-mile Alameda Creek Watershed is the largest watershed in the Bay Area, draining roughly the southern two-thirds of the East Bay. It extends as far south as Mount Hamilton, north to Mount Diablo, east to the Altamont Hills in Livermore, and west to San Francisco Bay. There are two major tributaries to Alameda Creek, with many smaller creeks feeding in to them: Arroyo de la Laguna in the north and the south fork of Alameda Creek. The watershed is crossed by two major water delivery systems for the Bay Area, the Hetch Hetchy Aquaduct and the State Water Project, and includes three man-made reservoirs: Lake Del Valle, San Antonio Reservoir and Calaveras Reservoir. Flows in the upper reaches of the Alameda Creek watershed are controlled by water releases from the Calaveras Reservoir, which is managed by the City and County of San Francisco. The Calaveras Reservoir captures natural runoff and stores imported water from the Hetch Hetchy reservoir. The local runoff in the Upper Alameda Creek Watershed is managed by Zone 7 Water Agency, while supplies for public and wildlife use come from the State Water Project. The Alameda Creek Watershed can be broken into two sections, lower and upper. The information in this watershed page focuses on the 198 square mile northern section of the Upper Alameda Creek Watershed. This section is split between Contra Costa and Alameda Counties, drains areas of San Ramon, Pleasanton, Dublin, Livermore and Sunol. The following subwatersheds are included in this northern section of the Upper Alameda Creek Watershed:
The northern section of the Upper Alameda Creek Watershed is characterized by large swaths of open space in its northern and eastern portions, transitioning to more suburban and urban areas of San Ramon, Dublin, Pleasanton, and Livermore along the western and southern edges. In the undeveloped portions of the watershed, waterways remain largely free flowing as they make their way through open range. In the transition zone between urban and rural areas, creeks flow through small ranchettes, where houses sit on multiple acres, and often along the creek edge. Upon reaching the urban edge, many of the creeks enter engineered channels, which help control flows as they pass through busy cities on their way to the Arroyo de la Laguna, eventually joining Alameda Creek in the Sunol Valley. Although this portion of the Upper Alameda Creek Watershed does not contain major dams like the portion to the south, it does contain some man-made features such as the engineered channels and the Chain of Lakes, a series of former quarry lakes located in the middle of the Livermore-Amador Valley.
Flora and Fauna
The northern section of the Upper Alameda Creek Watershed is home to a multitude of native plant and animal species. Characterized by a wide range of vegetation communities – grasslands, sage / scrub lands, oak woodlands, and riparian forest – the undeveloped areas of this section of the watershed contain a variety of native plants, including some special status species like the fragrant fritillary, maple-leaved checkerbloom and most-beautiful jewelflower. Small pockets of unique vegetation types such as alkali wetlands, fresh water marshes and alkali meadows are scattered throughout the area as well, concentrated in the Arroyo Las Positas Subwatershed.These vegetation communities also provide habitat for many native birds, amphibians, reptiles, bats and other mammals. The waterways and waterbodies within the northern section of Upper Alameda Creek Watershed provide especially important habitat, as the edges of ponds and the riparian areas along creeks are home to special status species such as the California red-legged frog, California tiger salamander, western pond turtle, and tri-colored blackbirds. Historically, the creeks in the northern section of the Upper Alameda Creek Watershed hosted over a dozen native fish species. Although anadramous species are no longer able to access the upper reaches of the watershed due to downstream barriers, other native fish – like riffle sculpin, hardhead and rainbow trout – still utilize these creeks.
The largest issue in this portion of the Upper Alameda Creek Watershed is the rapid growth of the urban and suburban areas of Dublin, Pleasanton and Livermore. Developed areas often contain large amounts of impervious surfaces, which reduce groundwater recharge and may increase contaminants and litter in surface water (such as creeks). Creeks flowing through urban areas are often channelized to control flows and alter stream location. Channelization, which often includes straightening a creek’s natural path, can reduce the amount of native riparian habitat along creek banks and create an environment that is inhospitable for native plants and animals.As with the rest of the Alameda Creek Watershed, dams create barriers for upstream fish migration to the northern section of the Upper Alameda Creek Watershed. This portion of the watershed is not currently accessible to steelhead, although this species was historically present and have been observed downstream from barriers.
The following information pertains to the northern section of the Upper Alameda Creek Watershed, which includes the following subwatersheds: Arroyo de La Laguna; Alamo Canal; Arroyo Mocho Canal; Arroyo Las Positas; and Chain of Lakes. To download a printable PDF map, click on the subwatershed name.
Arroyo de la Laguna is a 29-square-mile subwatershed of the Alameda Creek Watershed that drains flatlands and hills of the southern Amador Valley (covers areas of Pleasanton and Sunol), and transmits flow from six other subwatersheds including Alamo Canal, Arroyo Mocho, Arroyo Mocho Canal, Arroyo Las Positas, and Arroyo del Valle. Historically, much of the eastern part of the Amador Valley consisted of a lake known as Tulare Lake. With development of the valley starting in the 19th century, drainage alterations in this watershed reduced the lake to a creek now called the Arroyo de la Laguna. The 7.5 mile Arroyo de la Laguna creek originates at the confluences of South San Ramon Creek and Arroyo Mocho then flows south to Sunol Valley where it joins, and is the major tributary to, Alameda Creek. The Arroyo has steep banks with an oak-sycamore canopy cover at the top of banks and riparian forest/scrub in and along the margins of the active channel. Red willow (Salix laevigata), arroyo willow (Salix lasiolepis) and Fremont cottonwood (Populus fremontii) are the most common dominant canopy species in this habitat. Over time, additional development and changes in this section of the watershed have caused instability in the lower five miles of the Arroyo de la Laguna. The Arroyo has also been highly altered throughout the years, with activities ranging from heavy vegetation removal to development along its banks in some sections. These activities in the watershed have caused cumulative effects, resulting in extremely high flows, streambank erosion and channel widening of the Arroyo and increased sedimentation of Alameda Creek. Restoration efforts have been made to address these issues. The following creeks are also found in this subwatershed: Sinbad Creek; Pleasanton Canal; Kottinger Creek; Mission Creek; Sycamore Creek; Happy Valley Creek; Sheep Camp Creek; and Vallecitos Creek.
Alamo Canal is a 44-square-mile subwatershed of the Alameda Creek Watershed that drains northern Amador Valley (sections of San Ramon, Dublin and Pleasanton) and a portion of the hills south of Mount Diablo (spans portions of both Contra Costa and Alameda Counties). The northern two-thirds of this watershed falls within Contra Costa County, but drains south into Alameda Creek. Alamo Creek drains the foothills of Mt Diablo flowing parallel to Tassajara Creek, but through the west side of Dublin near San Ramon. Alamo Creek becomes Alamo Canal at its confluence with San Ramon Creek. The Alamo Canal ends at its junction with Arroyo Mocho, where both flow into Arroyo de la Laguna, which eventually flows into Alameda Creek. The following creeks are also found in this subwatershed: West Branch Alamo Creek, South San Ramon Creek, Coyote Creek, Norris Creek, Oak Creek, Big Canyon Creek, Martin Canyon Creek, Dublin Creek, Gold Creek, and Tehan Canyon.
Arroyo Mocho Canal is a 39 square mile subwatershed of the Alameda Creek Watershed. The Arroyo Mocho headwaters originate in the far northeastern corner of Santa Clara County and flows northwesterly into eastern Alameda County. The creek flows naturally through rural woodland and grassland habitats along Mines Road on its way to the Livermore Valley. The Arroyo Mocho canal subwatershed begins in west Livermore and carries the flow of Arroyo Mocho northwest through the Chain of Lakes subwatershed, to join with Arroyo Las Positas. From this junction it flows west through Pleasanton, collecting water from Tassajara Creek and Chabot Canal. Eventually it flows through an engineered channel until joining Arroyo de la Laguna northwest of Rose Canal. Arroyo Mocho means “cutoff creek” because historically it had no outlet but dissipated into the ground after spreading out into many smaller streams. As early as 1852 it was also called Mocho Creek, then expanded in the late 1800’s to create a wider canal for farming.
Arroyo Las Positas is an 81-square-mile subwatershed of the Alameda Creek Watershed that drains the Altamont pass, and areas just north and east of Livermore. Arroyo Las Positas is a 7.4-mile-long westward-flowing watercourse that originates from Arroyo Seco north of Livermore and empties into Arroyo Mocho in Dublin. Is the driest subwatershed in the Alameda Creek Watershed with mostly intermittent creeks and sparse riparian cover. The Arroyo las Positas conveyed the first historic State Water Project flows in May 1962 when water from the South Bay Aqueduct was released into Altamont Creek and flowed down to Arroyo Las Positas for local groundwater recharge. In 2003 Zone 7 Water Agency constructed two fish ladders as part of a project to widen, realign and restore the confluence of Arroyo Mocho and Arroyo Las Positas in Livermore. The ladders will allow steelhead trout the potential to access spawning and rearing habitat in the Arroyo Mocho gorge when barriers in lower Alameda Creek are removed. Other creeks in this subwatershed include: Altamont Creek; Arroyo Seco; Cayetano Creek; Collier Canyon Creek; Cottonwood Creek; and Frick Lake.
Chain of Lakes is a 4.6 square mile subwatershed of Alameda Creek Watershed. It is a series of former quarry lakes, including Cope Lake and Shadow Cliffs Lake, located in the heart of the Livermore‐Amador Valley. The Chain of Lakes and was envisioned as a large facility to be used for water management purposes by Zone 7 Water Agency. The water from the lakes drains into the ground, slowly filling the aquifers of the Livermore-Amador Valley groundwater basin. Zone 7 has prepared a Preliminary Lake Use Evaluation for the Chain of Lakes that discusses the uses and future plans for the Chain of Lakes in great detail.
The following information pertains to the northern section of the Upper Alameda Creek Watershed.
Alamo Creek Park is a 5.3 acre neighborhood park located near Dougherty Road and Willow Creek Drive in Dublin. Alamo Creek makes a wide bend around this city park, providing opportunities for viewing this beautiful natural section of creek.
Brushy Peak is a 1,833-acre preserve in East Livermore that offers great opportunities for hiking, biking, running, wildlife viewing and dog walking on the park’s scenic trails. It’s a 1,702-foot landmark at the juncture of the San Francisco Bay Area, the California Delta, and the Central Valley. The peak has been recognized as sacred by generations of native Californians. Due to its geographical position, the area lies at the center of a network of historic trade routes that linked Bay Area Ohlones, Bay Miwoks, and Northern Valley Yokuts.
Forest Home Farms Historic Park is a restored and maintained historic working farm in the City of San Ramon. Classes and programs are offered for the public. It is located on Oak Creek, a small tributary to San Ramon Creek.
This trail follows Martin Canyon Creek for 0.89 miles and offers views of the Tri-Valley. From Silvergate Drive, walk upstream on the south bank along a newly restored reach of Martin Canyon Creek. The City of Dublin has established a graded trail, with views of the meandering creek and good shade from oak and bay trees.
Located on Gold Creek, which is a small tributary to Alamo Canal. The creek is the central feature of this shaded city park. In 1871, a man prospecting for coal found a gold nugget and this “find” inspired a brief but unprofitable gold rush which gave the creek its name.
A preserve in the city of Pleasanton bounded by Laurel Creek Drive, Foothill Road, and Moller Ranch Drive. From the upper trailhead parking lot, a steep, narrow trail descends into a beautiful little canyon shaded by bay trees. This tributary to Gold Creek is in a virtually undisturbed condition.
Formerly a gravel quarry, Shadow Cliffs was donated to the East Bay Park District by Kaiser Industries and opened as a park in 1971. The Park District has developed a 266-acre park including an 80-acre lake and with parking and picnic grounds. A haven for swimming and fishing can be found at Shadow Cliffs, only a mile from downtown Pleasanton on Stanley Boulevard. The park includes facilities for persons with disabilities. Besides the main lake, Shadow Cliffs has an arroyo with a chain of smaller lakes and ponds.
This 10-acre community park is located near San Ramon Road in Dublin. Koopman Canyon Creek meanders its way through the park and is a great place for exploring nature. Look for native riparian species and birds in this tree-shaded reach. Downstream from the last bridge, the tree canopy opens up and the creek flows through a sunny marshland before entering a canal. The canal then flows into a storm drain underneath San Ramon Road. The park also features a water play area and bronze art display.
This small park is a great spot for bird watching, with American Kestrels, White-tailed Kites, Western Scrub Jays, and other species. A quaint wooden bridge spans Tassajara Creek, with large oak and willow trees providing shade for the views up and downstream of this natural creek reach.
Restoration efforts are ongoing in the northern section of the Upper Alameda Creek Watershed. These efforts target a wide variety of issues including stream bank improvements, groundwater recharge, and native habitat restoration.
Streambank Restoration and Revegetation
Zone 7 Water Agency works in conjunction with other agencies and organizations including the Alameda County Flood Control and Water Conservation District, Alameda County Public Works, San Francisco Public Utilities Commission, the Alameda County Conservation Partnership, Living Arroyos, and cities within the Tri-Valley area to improve stability and native habitat along stream banks throughout the northern section of the Upper Alameda Creek Watershed. These projects range in scale and include a wide variety of structural, vegetative, and management activities. Some involve moving full-sized trees and boulders to better manage high water flows in major creeks like the Arroyo de la Laguna, while others involve work to improve slope stability along urban canals by planting native grasses. A number of projects have focused on planting native trees along the banks of streams throughout the watershed, which will help keep streams at the correct temperature and provide habitat and food for native animals.
Native Habitat Restoration
A variety of organizations and agencies engage regularly in large and small scale habitat restoration efforts throughout the northern section of the Upper Alameda Creek Watershed. Such efforts include creating wetland areasthroughout the watershed (which were historically drained and removed causing a large-scale loss of this habitat in past centuries), allowing for needed water to flow into the unique habitat found in the Springtown Preserve alkali sink, and enhancing upland habitat that is home to special status species. Local agencies throughout this portion of the watershed are engaged in the East Alameda County Conservation Strategy, a large-scale planning effort which will help develop a long-term plan for habitat protection and encourage the implementation of conservation stewardship projects by landowners throughout the area to help offset impacts from local land use, transportation or other infrastructure projects.
South Decoto Green Streets Project
Numerous agencies throughout Alameda County offer programs and educational materials targeted at reducing contaminants from urban centers, removing litter from creeks within this portion of the Upper Alameda Creek watershed, and preventing trash from entering streams and creeks. The Alameda Countywide Clean Water Program provides free information about ways the public can reduce contamination inputs to local creeks, public education campaigns about proper waste disposal, and shares volunteer clean up days for interested residents of Alameda County. A number of agencies operating in this portion of the watershed support the Adopt a Creek Spot Program, which allows participants to help improve water quality and aquatic habitat in neighborhood creeks through organized litter clean-up events. Alameda County also adopted an ordinance to limit the distribution of single-use plastic bags in groceries stores in 2013 and expanded the ordinance to retail and dining establishments in 2017. Plastic bags are one of the most common litter items found in our waterways and are a threat to the health of animals who use these creeks. Another effort to keep the creek clean are the construction of Green Streets, which capture, retain, and treat stormwater runoff from impervious services, such as roadways, parking lots, sidewalks, and rooftops.
As with many other watersheds in Alameda County, the Alameda Creek Watershed historically had healthy populations of anadramous fish – specifically, steelhead trout. Instream habitat quality throughout major portions of Alameda Creek has been limited by reduced instream habitat complexity and migration barriers. The northern watershed has been extensively altered by urban development and channel modifications. Nearly a dozen agencies and organizations work closely as the Alameda Creek Fisheries Restoration Workgroup to collaboratively address the local implications of the steelhead trout being placed on the federal Endangered Species List and pursue steelhead restoration. Numerous local agencies are also working directly with the National Marine Fisheries Service through a cooperative agreement on their preparation of a Recovery Plan to address steelhead recovery throughout the Bay Area, including a specific vision for steelhead restoration in the Alameda Creek Watershed. As part of Zone 7 Water Agency’s efforts to restore steelhead populations, fish ladders have been installed along both the Arroyo las Positas and Arroyo Mocho.
Over the next 25 years, Zone7 Water Agency will take ownership of a total of ten gravel mining quarries. Zone 7 plans to create a “chain of lakes” from these pits, that will eventually aid in stormwater storage, groundwater recharge, and surface water storage and conveyance. As the quarries are restored to make them more suitable for these primary uses, they will also provide secondary uses such as protected wildlife habitat and enhanced wildlife corridors.
There are a number of groups and organizations who provide opportunities for individuals to get involved in many ways in the northern section of the Upper Alameda Creek Watershed. The Tri Valley Creeks Adopt a Creek Spot Program is a partnership program that encourages the public to get involved to reduce litter and allows participants to help improve water quality and aquatic habitat in neighborhood creeks. The Alameda Creek Alliance works to restore native species and habitats and to protect undeveloped areas within the watershed. It hosts an informative and well-organized website with an abundance of information about these efforts. The Alameda Creek Watershed Forum (acwForum) coordinates multiple stakeholders to protect and enhance beneficial water-related uses and resources in the watershed. The acwForum hosts an annual conference and coordinates or sponsors specific projects, such as creek and watershed signage, “adopt a spot” areas, and a sediment forum. The San Francisco Estuary Institute’s Alameda Creek Historical Ecology Study provides in-depth analysis that informs current salt marsh and steelhead restoration efforts in the watershed. The East Bay Regional Park District and the Regional Parks Foundation provide many opportunities for volunteerism and education within the watershed. Living Arroyos is a multi-agency partnership to enhance and maintain the urban streams and streamside habitats of the Livermore-Amador Valley and conducts community workdays.