SCH Number 2011082002

Project Info

Title

Geyserville Bank Stabilization, Riparian Revegetation, and Fish Habitat Enhancement Project

Description

The project site is located on the left (eastern) bank of the Russian River, some 300 ft. downstream of Geyserville Bridge in Sonoma County, CA. Historical aerial photographs show that the site has been relatively stable in recent decades until works to protect the Geyserville bridge redirected flow against this bank, while expanding the eastern edge of the massive gravel bar that now occupies most of the river in this location. Severe erosion to the project site has occurred over the last year. Site survey has revealed freshly-exposed vertical banks behind many fallen mature trees with a large section now completely lacking riparian vegetation. From inspection of a section of the exposed bank, it appears that the original sandy bank was at some point in the past, stabilized with debris, mostly concrete slabs mixed with construction debris. The aggressive erosion process is likely to continue, contributing many more tons of fine sediment (alluvial sand and levee topsoil) along with construction debris into the river, together with several more mature trees that are now close to the edge of the bank. The length affected by the erosion and the proposed work is 497 feet. If the erosion is allowed to continue for even one more winter there is indication that the existing healthy riparian will continue to erode another 500 feet downstream. 38' 42' 45.75"/122' 53' 38.03". The California Department of Fish and Game is executing a Lake and Streambed Alteration Agreement Number 1600-2011-0200-3 pursuant to Section 1602 of the Fish and Game Code to the project Applicant, BioEnginering Associates, Inc.

3 documents in project