Crews broke ground this summer on a project to reconstruct an aging residential stormwater facility, known as Encore, near NE 152nd Street and NE 20th Avenue in the Whipple Creek Watershed.

Why is Clark County doing this project?

The Encore site was designated as a stormwater facility in the 1980s when development of the surrounding area began. Two existing ponds on the site currently receive stormwater from the surrounding neighborhoods. Analysis of existing conditions, however, shows that the site provides a negligible amount of stormwater control insufficient to meet the present-day requirements for new development. In fact, only the flows from very large storms are controlled by the existing ponds. Reconstructing or ‘retrofitting’ the ponds will provide better stormwater management for this area, helping to curb stream erosion and habitat degradation observed downstream of the site.

What is the scope of the project?

The project excavated a large pond and redesigned the control structures on the site to detain and slowly release runoff from storm events. Additional work will enhance on-site wetlands with native plants to provide for more effective treatment to remove pollutants.

What are the benefits?

The reconstructed ponds are expected to provide nearly 10 acre-feet of detention and reduce peak flows by greater than 50% for a wide range of storms, reducing downstream erosion and habitat degradation. Additionally, over 1,000 native trees and shrubs will be planted on the site for water quality and habitat improvements.

Project Manager: Scott Fakler, (360) 397-6118, ext. 4264 or Email scott.fakler@clark.wa.gov

Existing pipe discharging into the Encore facility

Excavation of the new pond where water will flow from the top of photo to the right

Staging for construction of the pond outlet that controls the rate of stormwater released.