Easkoot Creek drains an area of approximately 1.59 square miles of mostly undeveloped and steeply forested watershed on the side of Mt. Tam. Early maps depicting the proposed subdivision development in the 1900s show the creek channel close to its present alignment until just downstream of the sharp turn at Arenal Avenue. The historic channel then branches off as the channel slope loses its grade and enters a willow thicket (on the current Park Service land). Early maps show an alternative alignment for Easkoot Creek breaching the sand dunes. With the development of Stinson Beach and the public park, Easkoot Creek has been maintained in its current alignment to Bolinas Lagoon.
There are three sources of flooding in Stinson Beach: overflow of Easkoot Creek, extremely high tides, and extremely high surf. Each of these alone can cause some flooding and when combined, can cause substantial flooding, property damage and public safety problems. The Arroyo and Calle area of Stinson beach are flooded annually during extreme high tide events.
Initially, when Flood Control Zone 5 was established one of the primary maintenance tasks performed was periodic dredging of the creek. Over time it has become evident that during medium to large storm events an active slide on Mt. Tam releases enough hillside material to fill in the creek, even if it has recently been dredged.
The essentially flat reach from Arenal to Bolinas Lagoon creates a slower moving creek and a natural area for sediment to settle and deposit. The excessive sediment build-up within this reach of Easkoot Creek has significantly reduced the level of flood protection through the Calle area of Stinson Beach. The private bridges along the residential streets known collectively as the “Calles” have limited to no clearance from the creek during storms, which may contribute to the flooding of neighboring homes and preclude access to and from Shoreline Highway. These bridges are a hydraulic constraint, but they are the primary access to homes and the primary access for emergency vehicles. The County and Flood Control Zone 5 has spent significant funds to perform limited dredging at the Calle bridges that is typically effective for only one to two seasons and requires dewatering the channel and relocating Steelhead trout to minimize impacts. As a condition of the sediment removal permit, the regulatory agencies have required that we investigate alternatives to the dewatering and the spot dredging approach since the creek has an established run of Steelhead. Staff are working with the National Park Service to explore the feasibility of constructing an interim sediment basin on Park Service property downstream of Arenal Avenue to capture sediment in one location instead of multiple locations downstream thus reducing impacts to Steelhead and other aquatic life.
Learn more about the history and habitat of Bolinas Lagoon.
The overall goals of the Stinson Beach Flood Protection and Watershed Program Special Tax are to raise funds to reduce riverine flooding risk for residents, visitors, and businesses; maintain natural creek functions; reduce sediment entering Bolinas Lagoon; and incorporate habitat enhancements fo
Jon Liang - Zone Engineer
Telephone No. (415) 473-6215
Zone 5 was created in 1961 to address creek and tidal flooding in Stinson Beach. It is overseen by a 5-member Advisory Board.
It is small, covering 2.28 square miles of entirely unincorporated lands in the community of Stinson Beach. There are 921 parcels in the Zone. The boundaries of the Zone and the Easkoot Creek Watershed closely align. The tributaries Fitzhenry, White Rock, and Black Rock Creeks join Easkoot Creek before it flows through Stinson Beach and out to the Pacific Ocean.
Zone does not have pump stations or levees; the Zone 5 work program is limited to an annual vegetation maintenance program along 0.25 miles of creek and periodic maintenance of a sediment basin. In the past, the Zone has periodically dredged Easkoot Creek, as an active slide on Mt. Tamalpais releases quantities of hillside material that fills the creek. Current Zone funding is no longer sufficient to do this work.