The Goleta Slough Watershed
This program focuses on San Jose and Maria Ygnacio Creeks. Both of these creeks are major tributaries to the Goleta Slough.
The Goleta Slough is almost entirely surrounded by urban development, some of which extends into areas that were once wetlands. This includes the Santa Barbara Airport to the north, public utilities and light industrial uses to the east, a public beach between the ocean and the slough, the campus of UC Santa Barbara to the south and west, and residential and light industrial operations extending beyond the immediate vicinity on all but the southern ocean boundary.
The slough has a watershed of 47 square miles, distributed among six major drainages. Each of these drainages is affected to a varying degree by human land uses such as urbanization and agriculture. Atascadero Creek is the most urban, while Los Carneros Creek is the least urban. All drainages have at least some agriculture, however Glen Annie Creek has the most intensive agricultural use (citrus and avocado orchards). Agriculture and urban uses typically contribute significant amounts of pollutants to both creeks and the slough. The vast majority of flow in these streams comes from flash discharges during major storms. While perennial water flows in the mountains, it rarely reaches the foothills during the dry season, and most of the slough’s tributaries run dry relatively early. The major exceptions are Glen Annie and Atascadero creeks, where agricultural runoff and urban seepage and landscape watering (“urban nuisance” water) provide low flows throughout the year. Please see our Goleta Stream Team Report, 2002 - 2005, for more detailed information on each drainage.
A Brief History
It is estimated that Native American peoples began inhabiting the area some 9,000 years ago. Early European explorers used the embayment as an anchorage for large ships until the 1860s, when severe storms in the winter of 1861-62 filled the bay with sediment. Cattle ranching in the surrounding area began in 1846, followed by agricultural development on the uplands around the slough. Agricultural use of the slough began in the 1870s, and the following decades saw the construction of berms, dikes and roads that further extended this development. A whaling camp was established around 1870, asphalt mining commenced in the 1890s, development of small farms expanded to cover the entire mesa in the 1920s, and rapid urbanization began in the 1940s. In 1928, a landing strip was established in the northeastern portion of the slough; it was expanded in 1942-43 during construction of a Marine Corps Air Station, and is now the Santa Barbara Airport.
The slough now includes approximately 430 acres of wetland habitat – drastically reduced from its estimated 1,150 acre historical size. Extensive areas of the historic marsh that were below the high-tide line are now isolated from tidal influence by berms and dikes. Tidal flooding is currently limited to the south-central portion of the slough; while tidal flooding still extends up into several of the major tributaries, its amplitude has been greatly diminished. During the summer months, tidal flows become reduced and eventually eliminated by formation of a sand berm at the mouth of the slough. This beach berm is often mechanically breached to maintain water quality in the slough.
A 1996 document reported 279 bird species observed at Goleta Slough; of these, 121 were water-associated, including several species of special status, including California brown pelican, southern bald eagle, peregrine falcon, snowy plover, sandhill crane, common loon, American white pelican, double-crested cormorant, white-faced ibis, fulvous duck, harlequin duck, northern harrier, golden eagle, osprey, long-billed curlew, California gull, elegant tern, and black skimmer.