Project Information

Bid Title

Ross Dam Low Level outlet Project

Issuing Agency

City of Seattle

Location

Washington

Published Date

Aug 31, 2025

Closing Date

Oct 10, 2025

Government Level

State & Local

Status

Closed

Ref. #

767061597

Original Source

Join to Access Full Details

Bid Inquiries

Join to Access Full Details

Bid Documents

Join to Access Full Details

Project Description

Project ID: 767061597

Title: Ross Dam Low Level outlet Project

Addenda: 0

Release Date: 8/29/2025

Due Date: 10/10/2025

Post Information

Posted At:Fri, Aug 29, 2025 12:00 PMSealed Bid Process:Yes (Bids Sealed / Pricing Sealed)Private Bid:No

Overview

Summary

The City of Seattle is seeking qualifications for Ross Dam Low Level outlet Project . Qualifications are due no later than 11:59 pm on Friday, October 10, 2025 . All questions are to be submitted through the e-procurement portal at https://procurement.opengov.com/portal/seattle no later than 11:59 pm on Friday, September 19, 2025 .

Background

The Ross low-level outlets (LLOs) are a critical dam safety component of Ross Dam. They enable released from the lower portion of the reservoir and are not currently fully accessible for maintenance and inspection. Under the Federal Energy Regulatory Commission’s (FERC) Dam Safety regulations, the LLOs must be inspected, tested, and maintained to ensure safe and reliable operation.

The LLOs convey water through two 72-inch-diameter steel penstocks also referred to as outlet conduits or bypass penstocks that are located in an approximately 350 feet long by 28 feet wide rock blasted tunnel. Portions of the tunnel and penstocks sit below the level of Diablo Lake which causes the tunnel to fill with water over time. The tunnel was designed to operate dry, but it is currently flooded. The water in the tunnel exceeds pollutant standards established under Washington administrative code (WAC) and cannot be discharged without treatment and approval from the Department of Ecology.

In approximately 2014, City Light obtained a National Pollutant Discharge Elimination System (NPDES) permit authorizing the discharge of treated water from the tunnel using electro-coagulation as the treatment method. In 2023, Water Tectonics was contracted to perform this work and the divers found that the material and conditions were vastly different than expected. During the project, divers discovered that the material and conditions in the tunnel differed significantly from expectations, as documented in Exhibit A: Water Tectonics Summary Report. The area contained woody debris which was removed, and the contaminated sediment was thicker and more solidified than anticipated. Exhibit B: Discharge Monitoring Reports September – November 2023. The work concluded when the weather window closed; the floors of the first three bays (Bays 7-9, approximately. 100 feet) were hydrovacuumed. The remaining tunnel bays were not completed, and Bays 7-9 will require reevaluation to confirm their condition.

The goal of this project is to return the Ross LLO tunnel to its designed state, by dewatering the tunnel and ensuring contaminants are not released into Diablo Lake

The project site along the downstream side of City Light’s Ross Dam on the Skagit River in Whatcom County, approximately 130 miles northeast of Seattle. The site is located in the North Cascades Recreational Area, part of the National Park System. This is a remote site and accessible only by boat.

Timeline

Solicitation Release:

August 29, 2025

Pre-Submittal Conference (Non-Mandatory):

September 16, 2025, 11:00am

Agenda

Meeting ID: 288 563 763 405 0
Passcode: Gw9GW3fZ
________________________________________
Dial in by phone
+1 206-686-8357,,351891901# United States, Seattle
Find a local number
Phone conference ID: 351 891 901#
Join on a video conferencing device
Tenant key: seattle@m.webex.com
Video ID: 112 809 083 2

Deadline for Questions:

September 19, 2025, 11:59pm

Response to Questions:

September 26, 2025, 11:59pm

Response Submission Deadline:

October 10, 2025, 11:59pm

Interviews if Conducted (estimated):

Week of October 27th, 2025.

Announcement of Successful Proposer(s):

November 18, 2025

Anticipated Negotiation Schedule:

November 18, 2025

Contract Execution:

December 5, 2025

Commodity Codes

• NAICS 237990Other Heavy and Civil Engineering Construction
• NAICS 238210Electrical Contractors and Other Wiring Installation Contractors

* Disclaimer: Government BidHub provides information on bids, RFPs (Requests for Proposals), and RFQs (Requests for Qualifications) solely for convenience and informational purposes. This site is not an official public notice board. For official details, responses, or inquiries, please contact the relevant government agency directly.