King County built a million-gallon underground storage tank across the street from Seattle’s Lowman Beach Park to reduce combined sewer overflows (CSOs). The tank stores excess stormwater and wastewater that would otherwise overflow into Puget Sound when the Murray Pump Station exceeds maximum capacity.

The short walls on the site are formed from rammed earth and the landscaping is meant to let the water pass through the site back to the water table. One issue with such an open site is the potential for graffiti but King County calls professional graffiti removal crews to come in and pressure wash structures that get tagged with spray paint.

The project contains:

• A pipe connecting the diversion structure to the storage tank to convey peak flows during a wet weather event
• An approximately 6,000 square foot underground storage tank across from Lowman Beach Park
• Retaining wall to protect the existing hillside along the northeast, east, and south edges of the storage tank site
• One story equipment facility including mechanical and electrical facilities, located above the storage tank
• Landscape restoration in Lowman Beach Park and above ground at the storage tank site
• A green roof with viewing areas
• Public walkway through the site with rain garden
• 3,500 square foot public use space north of facility

See King County's page about the project here.

Community celebration & facility tours
Saturday, June 10
10 a.m. to 12 p.m.

Murray Wet Weather Facility
The County will host a community event on Saturday, June 10 to celebrate the completion of the project and to thank you for your continued patience during construction.

Please stop by to:

 Take a tour of the facility (tours inside the facility building are limited to those ages nine and up)
 Learn about how the facility and underground storage tank protect water quality and public health
 Share your feedback about the project and construction process

Guided tours will begin at 10 a.m., 11a.m. and 11:30 a.m. Reserve your spot for a tour here: murraywetweatherfacilitytours.eventbrite.com