Musser Creek and Teanaway Road Flooding

The U.S. Forest Service, in partnership with Kittitas County, proposes to improve approximately 13 miles of the Teanaway and North Fork Teanaway roads.  Western Federal Lands Highway Division (WFLHD) evaluated design options for the road improvement project, including drainage system improvements.  Kittitas County retained WSE to review potential hydraulic concerns related to the proposed road improvement project near where Musser Creek crosses Teanaway Road.  This area is frequently flooded during large flood events and Kittitas County is concerned that the proposed project will exacerbate flooding of nearby homes.

Role / Services:  WSE estimated how hydraulic conditions downstream from the road might change if the WFLHD recommended culvert and road improvements were installed.  WSE reviewed the available data, developed a LiDAR topographic base map, completed hydrologic and hydraulic assessments, and recommended mitigation options.

Outcome:  WSE found that downstream flooding would not be significantly affected by upsizing the culverts.  WSE also shared findings with the County detailing areas currently susceptible to flooding.  WSE’s work was completed in June 2012 – the road improvement project is currently on hold pending additional USFS funding.