College of Marin at Indian Valley Ignacio Creek Stabilization Project

College of Marin at Indian Valley Ignacio Creek Stabilization Project

The College of Marin Indian Valley Campus is proposing to modify the stream bed and banks of Ignacio Creek in order to stabilize various stream reaches from erosion, protect pedestrian bridges, improve storm water outfall culverts, and enhance instream habitat. Implementation of the project will include the following: 1) Installation of a 30-foot long rock rip-rap structure on the right bank of Bridge 3 to protect the piers. 2) Installation of rock rip-rap at Bridge 4 will be installed around the upstream pier on the right bank (looking downstream). The V-section created by gullying on the left bank will be filled with rock rip-rap. 3) Installation of a 30-foot long rock rip-rap structure at Bridge 5 will be installed on the right bank (looking downstream) to protect the piers. 4) Installation of a 3-foot long rock rip-rap structure at Bridge 6 will be installed on the right bank (looking downstream) to protect the piers. The gully at the upstream end will be filled with rock. The concrete covered bank on the opposite side will be cut back approximately 3 feet. 5) Installation of four rock weir grade control structures at Bridges 7 & 8 will be constructed in the tributary to control incising of the channel, one upstream and one downstream of each bridge. 6) Bank stabilization at the "Corporation Yard," involving backfill with soil excavated on-site. The toe of the bank will be protected with rock rip-rap. The fill area above the rock will be planted with native riparian species. 7) Bank stabilization adjacent to the "Child Care Center" involving stabilization by brush layering with rock toe protection. The bank above the brush layering will be laid back and planted with native riparian species. The slide material on the opposite bank will be excavated and used as fill for the brush layering. The opposite bank will be laid back and planted with native riparian species. 8) Bank stabilization at the knickpoint involving vegetated rock rip-rap to be installed at the knickpoint to create a large grade control structure. Also, several storm water pipe extensions will be extended down into the Ignacio Creek and the tributary. Rock rip-rap will be placed by the end of the pipe to prevent erosion. The California Department of Fish and Game is executing a Lake and Streambed Alteration Agreement Number 1600-2008-0049-3 pursuant to Section 1602 of the Fish and Game Code to the project Applicant, V-Anne Chernock, College of Marin.

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