This purpose of this project was to analyze the patterns and locations of erosion and river channel migration in portions of the Sauk and Skagit Rivers, and to work cooperatively with the Mt. Baker-Snoqualmie National Forest of the United States Forest Service (USFS) to develop mechanisms to address property loss as a result of river channel migration in the Sauk and Skagit Rivers and their tributaries. This project was part of a larger planning effort that is being implemented in phases by multiple agencies in Snohomish and Skagit Counties.
SRSC compiled historic channel locations for the purpose of quantifying channel migration rates and assessing property loss over time. Historic aerial photographs of the Sauk and Skagit Rivers were identified and acquired from various sources including the USFS, Skagit County, Snohomish County, and the United States Army Corps of Engineers. The aerial photographs were scanned at a high resolution (800 dpi) and georeferenced to 1998 digital orthophotographs (DNR). Several land cover types were digitized including: wetted main channel, wetted side channel, main channel gravel bars, side channel gravel bars, main channel vegetated gravel bars, side channel vegetated gravel bars, and forested islands.
Project Status/Timeline
Seven historic photo year sets were acquired and mapped for the upper portion of the Sauk River extending from Clear Creek to the mouth of the Suiattle River (Aug 2006 – Jan 2007). Six year sets were acquired and mapped for the lower portion of the Sauk River extending from the mouth of the Suiattle River to the mouth of the Sauk River where it enters into the Skagit River (June 2007 – Oct 2007). The Skagit River portion, from the mouth of the Sauk River to the mouth of the Cascade River, as well as the property loss assessment, was completed in 2008.
Primary Project Contact
Kate Ramsden – GIS & Data Specialist
Funding Sources
Snohomish County
United States Forest Service
Project Partners
United States Forest Service