The Sausal Creek Watershed encompasses 2,656 acres in Oakland, California. The headwaters of Sausal Creek arise in the Oakland hills, and the creek flows through the city, discharging into the tidal canal that separates the island of Alameda from Oakland, which in turn flows into San Francisco Bay. For approximately half its length Sausal Creek forms a lush, seemingly natural riparian corridor, unique in this highly urbanized area. For the remainder of its length the creek is mostly culverted or channelized. Although approximately 20 percent of the watershed remains as open space, the watershed is an urban one, ranging from low-density residential development in the hills to a dense mix of commercial and residential uses in the lower reaches. The Sausal Creek Watershed is home to approximately 27,000 inhabitants of diverse backgrounds and cultures—African Americans, Asian Americans, European Americans, Latinos, Pacific Islanders, and Native Americans.
The watershed is also home to a diverse assemblage of plants and animals. Recent surveys have catalogued over 250 plant species and nearly 137 bird species inhabiting the riparian corridor and uplands. However, this ecosystem has been altered over time, and its present condition bears little resemblance to that of the past. Terrestrial and aquatic systems that were once integrated are now dissociated and fragmented by human activities such as logging, urbanization, and fire suppression. Consequences of these human activities include the alteration of the geomorphic processes that shape Sausal Creek, changes in plant communities and the process of plant succession,
and an overall loss of biodiversity.
Not only has the watershed's urbanization resulted in habitat loss, but its native diversity has been replaced in many areas by exotic species—Algerian and cape ivy displace native gooseberry and wild rose in the riparian corridor; eucalyptus and Monterey pine now grow where productive grasslands once clothed the hillsides; European starlings and rock doves occupy habitat once belonging to meadowlarks and burrowing owls. Nonetheless, many native species still make use of the creek and its banks. Black phoebes and Wilson's warblers, for example, frequent the corridor. Dogwood and scarlet monkey flower can occasionally be found growing along its banks.
Backswimmers still live in its pools, and damselflies hover above its waters.