4th St NW Storm System Upgrade


((UPDATED 2/2/23))

A majority of Phase N-1 is currently advertised for construction bidding.  The bid opening is planned for 2/22/23.  Construction is anticipated to start in mid-Spring, 2023 and continue through the fall.  

***NOTICE***  This construction project will create significant traffic impact for residents and road users.  Expect delays and changes to the traffic flow through the duration of this project.  This project will impact mainly 4th St NW, between North of River Road and South to Stewart Ave.  Lane shifts, lane closures, traffic control, and temp road closures are all anticipated to allow for construction of this new storm main.  Please use caution while traveling through the work zone.  Parking along 4th St NW will also likely be closed throughout the duration of the project.  


This project will install a new large-diameter (36"-42") stormwater main, rerouting and connecting the downtown drainage basin to the existing outfall to the Puyallup River at 4th St. NW (North of River Rd).  The existing downtown drainage basin drains to 4th Ave SW and out to the 15th St. Outfall to the Puyallup River.  The existing conveyance is shallow and lacks capacity and water quality treatment features. 

This project addresses a few major issues:

     (1)  Flooding.  The current lack of capacity causes flooding in several locations throughout the 4th Ave SW tributaries of the downtown area, during moderate and large rain storm events. 

     (2)  Water Quality:  Much of the downtown area was developed prior to water quality standards.  Currently stormwater from large areas of the downtown area, are discharged into the storm system and then ultimately to the Puyallup River.  This project will facilitate redevelopment of the downtown area, by providing a "Direct Discharge" to the Puyallup River.  Developers will not have to provide for very costly and prohibitive flow control requirements, which will make redevelopment feasible, in more cases.  The redevelopment will trigger Water Quality requirements, which would address the current lack of water quality features.

     (3)  Downtown Economic Development:  As stated above, current flow control requirements are a barrier to downtown redevelopment.  Flow control facilities (i.e. ponds, vaults, etc.) are very costly in an urban environment.  This project will remove some of those barriers by providing capacity to a Direct Discharge to the Puyallup River.  Basins that directly discharge to a flow control exempt waterbody (Puyallup River in this case) are exempt from flow control standards.  This will make redevelopment more feasible.  

The overall project is broken down into 5 phases (Phase N-1 through Phase N-5)

  1. Ryan Rutkosky, P.E.

    Senior Civil Engineer

4th St NW Storm Map


The project is broken into 5 separate phases:

Phase N-1:  Construction will occur on the majority of this phase in 2023, which includes North of River Rd, and all the way South to near Stewart Rd.  The remainder of this phase is anticipated to be constructed in 2024.  

Phases N-2 & N-3:  Design will begin in mid-2023.  

Phases N-4 & N-5:  These phases are not scheduled yet, however the City will proceed with these as funding and availability allows.