Welcome to the Shoreline Pump Station 26 Improvements Project - Virtual Open House and Survey Website!

The purpose of this Virtual Open House is to provide a chance for residents to:

• Learn more about this project
• Share what’s important to you and provide comment

Please scroll down to learn more about the proposed design and history of this project. The Open House also includes an optional survey for you to provide comments and questions on the project.

The survey is open August 11th and will close on August 20th. Questions submitted with the survey will be addressed during the live online Presentation on August 25th.

Thank you for your participation!

Project Overview

The City of Shoreline is proposing to replace the existing Surface Water Pump Station 26. The project will replace the existing pump station, pumps, force main, and detention pond. The detention pond will be replaced with an underground facility that will open up additional park space.  

Pump Station 26 is one of eight stormwater pump stations currently operating in the City and has been in operation since 1970. Located on the west side of 10th Avenue NE, a few hundred feet south of NE 185th Street, it detains runoff from a 74 acre, mostly single-family residential area to prevent flooding and move water to downstream piping that eventually flows to McAleer Creek. Now 50 years old, the pump station is past its intended operational life and has several parts that are out of compliance with current safety and stormwater codes. It has been identified in multiple studies as a candidate for replacement.

A Stormwater Pump Station Condition and Capacity Assessment was completed in 2016. This report evaluated the City’s eight existing stormwater pump stations, identified various deficiencies, and recommended general improvements for each station. It found Pump Station 26 in need of a total rebuild due to its age, lack of ability to handle high-runoff events without flooding, and frequent pump maintenance issues.

The following figure shows the existing detention pond:

(Click the image to enlarge)

In early 2019, the City put out a Request for Qualifications (RFQ) to hire a design consultant to design consistent pump station improvements across all eight of the City’s existing surface water pump stations. After review of multiple firm proposals, BHC Consultants was selected.

In mid-2019, BHC Consultants began the first phase of their scope, which was to assemble a Stormwater Pump Station and SCADA Improvements Preliminary Design Report. This report verified and expanded on the findings of the 2016 Conditions Assessment, provided telemetry design recommendations for all stations, and provided preliminary design for the two pump stations requiring full replacement, including Pump Station 26. The recommended improvements for Pump Station 26 include a new pump station, discharge and inlet piping, force main, telemetry, and conducted preliminary design and cost estimating for multiple detention facility alternatives to optimize flood control, flow control, park space, and cost.

The following figure shows the contributing area to Pump Station 26 from a Preliminary Modeling report by Brown and Caldwell, 2021. All surface area within the red boundary line flows by gravity pipe flow towards the low point at Pump Station 26.

(Click the image to enlarge)

The following figure shows the preliminary site plan proposed during the 2020 Pre-Design Report:

(Click the image to enlarge)

Proposed Schedule

Construction of the proposed project improvements will require temporary pumping operation while the existing pump station is being replaced. Therefore, construction is planned during the summer months and will break ground around April of 2022. Design and permitting work is underway to assure the current schedule can be met. Construction is estimated to take 8 months and complete at the end of 2022. The following graphic shows a general outline of the project schedule.

(Click the image to enlarge)

Proposed Site Plan

The following site plan shows the proposed pipe plan (Figure A). During a rain event, surface water runoff from the surrounding area will collect in the public pipe and catch basin network under the roadways. That runoff will enter the site through the Hydrodynamic Separator (Figure D), which collects sediment, oil, and other garbage for easy maintenance. Runoff then collects in the detention facility which is comprised of a pipe gallery of approximately 580 linear feet (LF) of 8-foot diameter perforated corrugated metal pipe. The pipe gallery is surrounded by drain rock to allow infiltration into the underlying soil (Figure B).

The wet well (Figure C) is the concrete container that houses the pumps and floats that detect the water level and is connected to the pipe gallery. When the water level in the pipe gallery reaches a pre-set level, one of the two pumps will turn on, forcing water through the valve vault (Figure C), through the new 12-inch diameter discharge piping (force main), which connects to the existing force main in the northwest corner of the site near where the existing pump station sits. From there, the force main runs north to NE 185th Street, then west to discharge to a catch basin in 8th Avenue NE intersection. Water then flows downstream through the piped system and eventually discharges into McAleer Creek.

Figure A) The following site plan shows the proposed piping plan:

(Click the image to enlarge)

Figure B) The following section shows the underground detention pipes facing west:

(Click on image to enlarge)

Figure C) Example of a Wet Well and Valve Vault:

(Click image to enlarge)

Figure D) Example of a Hydrodynamic Separator:

(Click image to enlarge)

The following figure shows the proposed park and landscaping plan above the pipe facility. The design includes a permeable concrete sidewalk and rain garden located off of 10th Avenue NE:

(Click image to enlarge)

Take the Survey

We would appreciate your feedback on this project. Please use the following survey to provide your comments and questions. If you ask a question by August 20th, we will try to answer your question during the live Presentation on August 25th.

There is also an optional community outreach survey that gives the City feedback on future outreach efforts.

Thank you!

Please consider filling out some information about yourself to help us improve our future outreach efforts. 

Community Outreach Survey (Optional)

English
የማህበረሰብ ተደራሽነት የዳሰሳ ጥናት (ከተፈለገ)
社區外展服務調查（可選)
커뮤니티 소통 설문 조사(선택 사항)
Encuesta de divulgación comunitaria (opcional)
Survey sa Paglilingkod sa Komunidad (Opsiyonal)
ንዝያዳ ኮማዊ ግምገማ(ብምርጫ)
Khảo Sát Tiếp Cận Cộng Đồng (Không bắt buộc)