12th Ave NW Basin Drainage Improvement Update

Seattle Public Utilities has issued a a Washington State Environmental Policy Act (SEPA) Checklist and Determination of Non-Significance (DNS) for the 12th Ave NW Basin Drainage Improvements Project. The SEPA Checklist and DNS can be found under “Project Documents” on SPU’s documents webpage at https://www.seattle.gov/utilities/neighborhood-projects/12th-ave-nw-basin.

Comments on the DNS must be submitted by Oct. 1, 2020 via email to:

Betty Meyer, SEPA Responsible Official
Seattle Public Utilities
betty.meyer@seattle.gov

Appeals of this DNS must be accompanied by an $85 filing fee and must be filed by 5 pm on Oct. 8, 2020. Please see the Office of the Hearing Examiner web site for Temporary Operating Rules During COVID-19: http://www.seattle.gov/hearing-examiner

Project updates

In April, we announced the proposed locations of new natural drainage systems. You can see a map of proposed improvements on our website.

Types of improvements

• Natural drainage systems – The natural drainage systems are sited in areas where they will provide the biggest drainage benefit while still being cost-efficient. Additionally, the selected locations avoid existing underground utilities and other significant structures.
• Trees – New trees may be planted inside the natural drainage systems or as stand-alone improvements. The tree locations avoid overhead utilities, maintain sightlines for pedestrians and drivers, and allow trees to be clustered for ease of maintenance and tree health.
• Grass planting strips – To make the natural drainage systems function properly, we will need to install additional underground support structures like pipes that will direct the captured stormwater flows to existing collection facilities. If we disturb the right of way to put in these support structures, we often restore it with new grass and trees when we’re finished (most of these areas are either grass, asphalt or gravel currently). The new grass isn’t part of an engineered drainage system in itself, but rather is a greener, more drainage-friendly way to restore disturbed right of way (grass and trees soak up rainwater better than asphalt).

If you live next to a proposed improvement and have questions or concerns, please reach out to the project team at SPU_BroadviewProjects@seattle.gov.

Looking ahead

• The project is moving toward 60% design.
• At this time, construction is anticipated to begin in fall 2021. We will update the community if there are any significant impacts to schedule.
• Additional outreach will be conducted closer to the start of construction, but we’re available to have one-on-one conversations (by phone, email or virtual meetings) with homeowners in the meantime. Please reach out to us if you have questions or concerns.

if you have a question about the project, please feel free to contact the project team by emailing SPU_BroadviewProjects@seattle.gov.