The City of Wenatchee has three seasonal watercourses that drain the canyons on the east slope of Mission Ridge into the City of Wenatchee’s urban area. These natural drainages are called No. 1 Canyon Drain, No. 2 Canyon Drain and Dry Gulch.  They allow rainwater and snowmelt to drain from the canyons to the Columbia River.   Even though these natural drainages flow through the City of Wenatchee they are separate from the City's urban stormwater system. 

Canyon Drain Projects

Flood Control Facility- 2014

In October 2014, the Chelan County Public Works Department completed construction on a 1.5 acre flood control facility within No. 1 Canyon.  The three basin facility was designed to provide increased retention time during high Canyon flows to allow for infiltration and holding of runoff.  As a result, a portion of the water within the No. 1 Canyon drainage is slowed down before it reaches the City of Wenatchee.  The County's newly implemented Flood Control Zone District is continuing to investigate other opportunities, similar to this facility, in both Canyons above the City.

The No. 1 Canyon Stormwater Facility in the fall of 2014

9th Street Basin Water Quality Retrofit

This project was designed and constructed to improve the water quality of the No. 2 Canyon Drain and the Columbia River through the installation of new stormwater pipes and treatment structures in the 9th Street Basin. The 9th Street Basin covers approximately 500 acres within the City of Wenatchee. Stormwater in this area discharges to the No. 2 Canyon Drain and to the Columbia River. Prior to the construction, stormwater discharged into the No. 2 Canyon Drain received no water quality treatment. 

This project brought the installation stormwater pipes, catch basins, and other best management practices (BMPs) to improve water quality of the waters that flow in the area and lead to the Columbia River.  Previously, the City stormwater system discharged by run off and sheet flow into the No. 2 Canyon Drain from Ringold Street and on to the Columbia River through an open ditch and piped sections which flow under ground through City streets and private properties. This project introduced basic treatment for the removal of total suspended solids (TSS) which reduces the pollutant volume reaching the Columbia River by routing stormwater from streets and parking lots away from the No. 2 Canyon drain and into the City's 9th Street Basin Stormwater system.  The total upper portion of the 9th Street basin totals 620 acres and runoff generally flows west to east toward the Columbia River. Land in this area includes the northern portion of the Wenatchee Valley College Campus at 1300 Fifth Street along Nelson Road. The sub-basin is bounded by 5th Street to the south and 9th Street to the north, totaling approximately 19 acres. A stormwater retention vault was installed on the Wenatchee Valley College Campus in the lower parking lot of the Wells House. Stormwater will travel from the vault then flow through pipes east to Morris Street, out to Ringld Street, then to 7th Street, turning north to connect to the existing stormwater pipes in 9th Street at the intersection of 9th Street & Princeton Avenue. 

 Canyon Drain Maintenance

The City of Wenatchee has obtained a Hydraulic Project Approval (HPA) to clean and maintain portions of the canyon drains that within the public right of way. This approval is required by the Washington State Department of Fish and Wildlife for any project near state waters, which includes the canyon drains.  This approval is required for all work and maintenance associated with the canyon drains, this includes work on private property. The HPA is indented to ensure that construction is done in a manner that protects fish and their aquatic habitats.

Common maintenance problems include:

• Overgrown vegetation
• Debris and yard waste dumped into the ditch
• Filling in or reducing the capacity of the water course
• Installing permanent structures that restrict or alter the flow (i.e. fences, sheds, decks, walls)
• Not removing debris and sediment deposited from previous flood events.

Resources for Property Owners

The Chelan County Flood Control Zone District partnered with Tetra Tech and Perteet Inc. to provide a comprehensive guidebook for landowners adjacent to the Number 2 Canyon Drain. To obtain a hard copy of the document, visit Wenatchee City Hall or call 509-888-3235.

No. 2 Canyon Landowners Handbook

Cascadia Conservation District

The City of Wenatchee has partnered with the Cascadia Conservation District as a resource for property owners wishing to maintain or modify the canyon drains on their property. Cascadia Conservation District has staff specializing in streamside maintenance, restoration, and capable of assistance navigating regulatory requirements.  For additional information:

               Visit the Cascadia Conservation District Website

               Call: (509)436-1601

               E-mail: info@cascadiacd.org

Property owners considering maintenance, modifications or repairs to the natural drainages on their property must to first call the Army Corps of Engineers and the Washington State Department of Fish and Wildlife.  Private properties must notify the following agencies prior to work on the canyon drains even during an emergency.

Regular Business Hours Contacts: (Monday - Friday, 8:00 am- 5:00 pm)

Department of Fish & Wildlife: Areas of Responsibilities Map: WDFW Assistance  (This map is updated regularly and has the most current WDFW contact information.)

Army Corps of Engineers:  Chelan County (This link will be updated with the most current contact information)

After Hours Emergency Contacts:

Department of Fish & Wildlife: (360) 902-2537

Army Corps of Engineers: (206) 200-9954

If you need sand bags, please call Chelan County Emergency Management at 667-6863.

The following is a map showing the routes that the canyon drainages take through town.

• Canyon Drainage Map 2012 (pdf)

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