Surface Water

Global Menu

Surface Water


Colony Creek, Colony Mountain Drive, Sediment Management and Flood Protection Evaluation Final Report
Prepared for Skagit County Department of Public Works Surface Water by northwest hydraulic consultants inc.

Skagit County Department of Public Works is seeking a reasonable solution to reduce flooding problems along a 3200-ft long reach of Colony Creek which borders Colony Road. Sediment has nearly filled the existing channel and two seven-foot diameter CMP culverts that carry the stream under Colony Mountain Drive. As a result, water frequently overtops Colony Road forcing the County to close it to traffic. The Washington State Department of Wildlife (WDFW), the agency responsible for issuing hydraulic permits to work in streams, would like the County to implement a long term plan to minimize the need to remove sediment from the stream and thereby reduce impacts to valuable salmonid habitat. The County retained Northwest Hydraulic Consultants to evaluate conditions at the site and identify a range of alternatives to reduce flooding and the need to remove sediments from the stream.