SCH Number 2008072049

Project Info

Title

Sediment Removal from Culvert, Old Bear Valley Creek Channel and Silver Hills Creek Drainage Ditches

Description

Marin Department of Public Works (DPW) proposes to excavate approximately 880 linear feet (0.15 acre) of wetlands and water of the U.S., resulting in removal of 893 cubic yards of sediment. A small dozer would be placed in the Old Bear Valley Creek channel to remove sediment from the bottom of the channel. Operating from the top of bank or road, a gradall would dig out accumulated sediment from this creek channel and adjacent Silver Hills Creek drainage ditches. Temporary cofferdams would be used to de-water the creek channel, isolate the work area, and protect water quality and aquatic resources. Excavation of sediment will result in the temporary loss of brackish and fresh water marsh vegetation and removal of 12 riparian trees (willows and alders approximately 2-8 inches in diameter). These habitats support the following listed threatened and endangered species that potentially occur wihtin the project area: California black rail, California red-legged frog, coho salmon and steelhead trout. MCDPW will emphasize avoidance of impacts to biological resources and water quality through the use of specific and general measures and provide in-kind replacement of removed riparian trees over 6 inches in trunk diameter.

3 documents in project