Venema Natural Drainage Project

Natural drainage system cells and plantings in the Broadview neighborhood.

Project Description

This project reconstructed 5 blocks of roadway in the Broadview neighborhood to include natural drainage systems and planting improvements. Venema Creek is a tributary of Piper's Creek and collects stormwater from over 80 acres in the Venema Basin. This system improves the existing flow, character, and pattern of infiltration of stormwater. This will restore the natural hydrological cycle, improve salmon habitat, and reduce the negative impacts of urbanization on Piper's Creek - and ultimately the Puget Sound.

The new natural drainage system is expected to reduce the average annual volume of stormwater runoff into Venema Creek. It will also significantly slow the flow of stormwater while improving the water quality.

Location

The project added natural drainage system cells along NW 122nd St and NW 120th St between 1st and 3rd avenues northwest.

Project Results

Natural drainage features on the project include a deep infiltration well alternative that will allow stormwater to be channeled into outwash soil after being filtered through the natural drainage system. These features help reduce the quantity and speed of the runoff. This helps Piper's Creek by reducing the occurrence of large, fast flows of water that can damage the creek channel and habitat.

Additional benefits of the project include:

• 1,600-feet of new, high-quality sidewalks
• Repaved road surface
• A roadway designed to calm traffic
• Driveway width within the public right of way meets City of Seattle standards
• New landscaping that will contribute to air and water quality

Timeline

Construction was completed in winter 2016.