Rediscovering the Peninsula: The forgotten Islais Creek

A principle collector and conduit for the Islais Creek was the Glen Canyon (called Rock Gulch at first) that channeled much of the water to the southeast and toward the Bay. The well gouged out, relatively flat canyon that formed on its journey toward the Bay afforded a much sought after site for many of the transportation systems (such as the San Francisco and San Jose Railroad, the Ocean Shore Railroad and the No. 40 Trolley Line as well as other trolleys) and that was to develop to serve the people transportation along the Peninsula. The fresh water in the creek became an unfortunate victim in the struggle to improve the transportation systems in this area and, by the 1970s, the creek was put in culverts and covered up with dirt in the final episode of building the interstate from Highway 101 to Daly City.

Much of the flow of water was slowed due to the abundance of native grasses and iris on the land next to the creek. A dynamite factory was erected here next to the creek but it blew up in 1869. The Good Brothers Dairy grazed cattle next to the creek in the 1800s. It wasn’t long before developers had opened the Mission Zoo in 1898 complete with wild animals, tightrope walkers, balloon ascensions and a red barn that offered dancing. At the intersection of Diamond and Chenery streets, a streetcar trestle was erected and potential land buyers were offered transportation to view the Sunnyside Land Company development that Behrend Joost was offering to people from the inner city. Joost used the water from the Islais for his boilers that generated electricity on which his streetcars needed to run.

Concrete culverts were laid down to channel the creek through the canyon in the 1930s and a recreation center was built in 1937 under the Works Progress Administration. In the 1930s, O’Shaughnessy Boulevard was constructed. In 1928, the Islais Creek that flowed through the canyon that led to the marshes east of Highway 101 was being forced into storm drains and Alemany Boulevard was constructed. The Islais Bay was crossed by the Southern Pacific Railroad in the early 1900s and the marshes were assaulted by dirt haulers. The 1906 earthquake produced a lot of debris and it was hauled here by trucks and a train and used as landfill. The land became prime property for industrial development and the Islais Creek was funneled through culverts, to empty into the Bay at Third and Islais streets north of Hunters Point. Due to construction of streets, housing, parking lots and loss of vegetation for these things, the once mighty Islais Creek no longer exerts an important role in the lives of the communities of San Francisco.

Ironically, south of Woodside, the small hilly/wooded community of Portola Valley has decided to “daylight” 650 feet of the south/north Sausal Creek that has been culverted. Recent study of creeks in cities and towns show that we may have acted too quickly when many of our waterways have been covered over. The water has little to impede their flow and causes flooding that could be avoided without the culverts. Much-needed water tables have been lowered due to culverting and many animals that have been a benefit to the communities have left the area where a habitat for their survival is essential. It seems that we may have acted too fast in our race for progress and need to rethink the benefits that creeks like the Islais may have on our quality of life.

Rediscovering the Peninsula runs every weekend. It is compiled through our archives created by Jim Clifford and the late Darold Fredricks.