Why is the City doing this Project?

The Walla Walla basin includes 2,586 acres of various land uses including fully developed residential, commercial, and industrial land uses. The majority of the basin was developed prior to requirements for stormwater treatment and incorporates most of the main arterials in the city including Fifth Street, 9th Street, Miller Street, Maple Street, North Wenatchee Avenue, the Apple Capital Loop Trail, and Chelan County PUD Walla Walla Park. Currently, stormwater in the Walla Walla basin flows to the Columbia River through a series of pipes, inlets, roadside ditches, and culverts and discharges to the river via the Walla Walla outfall. The outfall was constructed in 1970 and is located underwater within the Columbia River. The Columbia River is a Category 5, 303d-listed waterbody for pH, temperature, and dissolved oxygen, and is a freshwater waterbody designated for primary contact recreation and salmonid spawning, rearing, and migration. This project will improve water quality in the Columbia River through design of stormwater best management practices (BMPs) and possible relocation of the outfall in the Walla Walla basin in the City of Wenatchee. This project will help protect and restore water quality in Washington state by reducing stormwater impacts from existing infrastructure and development.

What will the Project include?

This project will study and design retrofits for water quality treatment of stormwater generated in the Walla Walla basin in the City of Wenatchee before it discharges to the Columbia River. This project will treat total suspended solids (TSS), oil (total petroleum hydrocarbons), and may reduce metals loading and flows to the Columbia River through increased infiltration or detention. This project is being partially funded by the Department of Ecology Stormwater Financial Assistance Program for Water Quality known as city project 2215, and Ecology WQC-2023-Wenatc-00076. The planning efforts will determine the best outcome for additional stormwater infrastructure, locations and best water quality treatment options. These efforts will also prepare the city for construction grant application for construction dollars to build the necessary infrastructure determined through these design efforts. 

For a more detailed map of the project please click here.  

More Project Details

September 2024- city to conduct soil testing to analysis infiltration rates and soil conditions. The results will help determine the best location and BMPs for water quality treatment.  Then we will advance the design to 60% and 90% plans. 

Timeline

Last Updated: August 2024
The City should have 90% design completed by Fall 2025, and then apply for construction funding Fall 2025.