Storm Water

What is Stormwater?

Stormwater is water that originates during precipitation events and snow/ice melt.  Stormwater can soak into the soil (infiltrate), be held on the surface and evaporate, or runoff and end up in nearby streams, rivers or other water bodies (surface water).  In natural landscapes, the soils absorbs much of the stormwater and plants help hold stormwater close to where it falls.  In developed environments, unmanaged stormwater can create major issues related to the volume and timing of the water (flooding) as well as wash contaminants into surface water.

When we develop land by building houses, roads and parking lots, we increase the amount of impervious surface in an area.  Impervious surfaces do not allow the water to naturally infiltrate into the ground and are also often covered in residues from vehicle traffic and other human activities.  Rainwater and melt off instead wash over these surfaces, taking with them contaminents.  The increased run off can clog drain systems, erode natural watercourses and flushes materials and pollutants into nearby rivers and lakes.

Stormwater NPDES Program

Program Pollutants carried in stormwater runoff are quickly becoming a leading cause of water pollution in rivers and lakes. The Urban Growth Area of Wenatchee falls under the National Pollutant Discharge Elimination System (NPDES) Phase II requirements which specify a set of actions to meet these Clean Water Act mandates. Chelan County is required to get a stormwater quality permit from the Department of Ecology for this service area under the NPDES regulations. This NPDES Phase II planning area will have the same boundary as the new Chelan County stormwater utility area.

In February of 2007, the Washington State Department of Ecology issued the Eastern Washington Phase II Municipal Stormwater Permit to the City of Wenatchee, Chelan County, Douglas County and the City of East Wenatchee. This permit requires each jurisdiction to develop and implement a stormwater management program (SWMP) with the goal of reducing the amount of pollution in stormwater.

Chelan County's SWMP can be found at the following links:

In addition, the permit requires each jurisdiction to maintain records on stormwater activates and provide annual reports to the Department of Ecology.

The Department of Ecology did not require a 2014 Annual Report

To share resources and develop a consistent regional stormwater program, representatives from both cities and counties have been working together to meet the requirements of the permit. This group is called the Wenatchee Valley Stormwater Technical Advisory Committee (WVSTAC). Over the past eightyears the program has be developed and implemented.

Chelan County Surface and Stormwater Management Utility

Chelan County Public Works, in addition to the Department of Ecology and the Environmental Protection Agency (EPA), are responsible for surface water management in unincorporated Chelan County pursuant to the Federal Clean Water Act and conditions set forth within the Department of Ecology’s Eastern Washington Municipal Stormwater Permit.

In carrying out this responsibility, Chelan County Public Works plans, designs, and secures permits for new public drainage facilities, reviews private drainage system designs and maintains existing public storm drainage and surface water management facilities.

In January 2008, Chelan County adopted a surface stormwater utility boundary and program to fund and manage the stormwater needs within the unincorporated areas around the City of Wenatchee. The Chelan County 2012 Comprehensive Stormwater Plan, dated July 2012, is the compilation of this effort. It provides detailed information on the stormwater systems, drainages, water quality, and deficiencies. The plan identifies and prioritizes stormwater projects which would address these deficiencies within the utility area. Additionally, the plan identifies possible funding sources to implement and complete projects.

Chelan County Comprehensive Stormwater Plan