Baby coho need healthy streamside forests and cold, clean water.

In most years a significant portion of the salmon that spawn in the Lagunitas Watershed spawn in the San Geronimo Valley. Last winter over half coho redds that were discovered in the entire watershed were found in the valley which includes the smaller creeks that run through the villages of Woodacre, San Geronimo, Forest Knolls and Lagunitas. This information will help you understand the impacts to the system and ways to protect and enhance the health of your watershed. We hope you enjoy their magnificent return and will continue to learn about the delicate balance between we humans and our salmon neighbors in the San Geronimo Valley. Please contact us if you have any questions or concerns.

Coho spawners await more rain in San Geronimo Creek at Forest Knolls. Photo: Bernie Lenhoff

Impacts:

The San Geronimo Valley is the highest density residential development within the LCW. The picturesque creekside habitat in this valley has attracted and encouraged the development on or very near riparian habitat. Today more than 3300 residents live in the valley on over 1500 individual parcels. Nearly 180 of these landowners own property directly adjacent to creeks. According to the San Geronimo Valley Community Plan (Dec. 1997), development along stream banks has created and exacerbated a number of fundamental problems in the riparian habitat zone including:

* increased bank erosion
* significant decline in salmon and steelhead populations (due in part to water diversions on the creek and sedimentation)
* degradation of water quality due to septic system failures, and creek obstruction.
* structural encroachment of creek causing bank erosion and channelization
* water temperature increases through loss of riparian vegetation
* migration barriers in the form of debris (dumping practices), stream crossings and culverts

The San Geronimo Valley Community Plan states:

"...the salmon and steelhead population [in the San Geronimo Valley] has suffered a substantial decline primarily due to siltation of gravel beds and pollution. In addition, loss of riparian vegetation has resulted in warming of the water temperature which is detrimental to the young salmon. Shade cover provided by existing trees and shrubs should be maintained and native vegetation planted to reduce the impacts of direct sunlight on the creek."

What can you do??

1) Maintain trees and plants along creeks. They keep creeks cool and keep creek banks stable. Let fallen trees and branches stay on banks and in the creek - as long as they don't threaten property.

2) Don't grade hillsides or leave soil exposed during the winter - plant fast growing native ground covers or cover soil with proper sediment control materials. Sediment and mud from erosion chokes salmon eggs and baby fish, robbing them of precious oxygen.

3) Don't walk in the creek or near the banks particularly during spawning season (October thru April).

4) Don't pump water directly from the creek or nearby wells.

5) Maintain your vehicle and prevent leaking fluids and don't wash your vehicle near a creek.