Magnolia Elevated Tank Rehabilitation and Improvements

View looking up at the Magnolia water tank. — Current view of the tank from the ground with project details noted: same paint color, enhanced crossbars for seismic support, and new, more secure fencing.

Project description

Preserving quality drinking water in your community.

Magnolia Tank is a 1,000,000-gallon water tank owned by Seattle Public Utilities (SPU) that serves customers in Magnolia. It is located in the Magnolia neighborhood in a block of open space between W Dravus St and W Prosper St, and 38th Ave W and 39th Ave W.

SPU will paint the tank’s interior and exterior (matching the existing color) to extend its service life and help preserve water quality. Seismic retrofit upgrades to the tank itself and fencing enhancements around the perimeter will help keep the tank, and the drinking water it holds, secure.

Location

Magnolia Tank is located in the Magnolia neighborhood in a block of open space between W Dravus St and W Prosper St, and 38th Ave W and 39th Ave W.

What's happening now?

In June 2026, the project accomplished the following:

Completed interior coating work.
Removed all scaffolding from the interior of the tank.
Completed trenching and pipe work to replace the existing inlet/outlet pipe and drain line.
Security cameras installed for 24/7 detection.

Tall scaffolding inside a large domed structure. — Installation of security cameras and their support equipment on the Magnolia Tank work site.

Abrasive blasting planned for the week of November 16

SPU and the contractor anticipate beginning exterior abrasive blasting the week of November 16, weather permitting and barring other delays. Blasting removes the old coating so crews can apply a new protective coating system to the tank.

What you may notice

Noticeable construction noise during blasting and cleanup.
The vacuum system used to collect spent blasting material can be very loud and may cause vibration that some neighbors feel inside their homes.
Vibration and shaking may occur at times while the vacuum is operating.
Depending on weather conditions, heaters inside the containment may need to run overnight. These heaters may be powered by generators and will use sound‑mitigation ducting to help reduce noise.
Active construction work will occur during standard daytime hours, though some equipment may operate overnight as needed to maintain conditions inside the containment.

Estimated blasting timeline

Blasting work of this kind usually takes 2 months to complete. Actual timing may shift based on weather and the condition of the existing coating, and some areas may take longer than others. SPU will continue to provide schedule updates as work progresses.

After this work is complete, we will progress onto the following work:

Coating the exterior of the tank should be complete in the spring of 2027.
Cell phone carrier construction could begin in the summer of 2027.

Community benefits

This project will extend the life of the tank and employ seismic retrofit technology for improved resilience against seismic activity. This work will reduce the need for future costly infrastructure improvements while preserving drinking water service and quality.

Schedule

Construction: Mid-2025 - 2028

Construction impacts

Residents can expect the following impacts during construction:

Typical weekday working hours are from 7 AM to 5 PM with work possible on weekends.
Construction traffic, noise, dust, and vibrations during working hours. Since the site is located on a higher elevation, sound may travel from the worksite.
Temporary street parking restrictions immediately adjacent to the tank.
Partial and full road closures with signage for traffic control.
Site will be fenced off for construction and equipment staging.
Tank will be temporarily wrapped in plastic for weather proofing during construction.
Temporary masts for wireless equipment.