WW-2 and WW-3 Warson Woods Sanitary Relief (12302)

WW-2 and WW-3 Warson Woods Sanitary Relief (12302)

As part of a long-term effort to reduce basement backups and sewer overflows, MSD Project Clear is constructing a project to replace approximately 10,000 feet of undersized wastewater sewers in the cities of Warson Woods, Ladue, Kirkwood, Rock Hill and Glendale. In addition, approximately 140 feet of natural creek will be stabilized to reduce creek bank erosion and improve water flow.

About the Project

Public Meeting - January 4, 2024

Public Meeting - September 2, 2020

Project Map

What is the goal of this project?

MSD Project Clear is investing approximately $13 million to improve wastewater sewers and prevent creek bank erosion by installing concrete lining and rock stabilization in the cities of Warson Woods, Ladue, Kirkwood, Rock Hill and Glendale. The goal is to reduce basement backups and sewer overflows, which occur when the sewers become overloaded during intense rainfall. This project will reduce such occurrences by increasing the size and capacity of the existing sewer. In addition, the creek in this area is experiencing erosion and this project will stabilize the creek bank to improve water flow and protect some of the nearby private properties from creek erosion. It will also allow MSD to eliminate 3 sanitary sewer overflow points.

Project Facts

  • Construction is estimated to begin in January 2024.
  • MSD Project Clear will replace approximately 10,000 feet of wastewater pipe.
  • MSD Project Clear will stabilize approximately 140 feet of natural creek bank erosion using a mix of rock lining, biostabilization, and a retaining wall.
  • The pipe size will increase to between 8 and 30-inches in diameter, allowing a larger amount of wastewater to flow through the system.
  • MSD Project Clear will repair and intercept overbank erosion and extend the existing storm sewers through the new channel walls with storm inlets.

How will it be built?

Some of this project will be constructed by digging through the surface, a process known as “open-cut.” The contractor will dig a trench several feet into the ground, remove the old sewer pipe, and replace it with a newer, larger pipe. However, for the majority of this project, tunneling will be used to avoid major traffic implications.

What can residents expect?

This project will be constructed by digging through the surface of the ground in a process known as “open-cut” construction. The pictures above depict what a neighborhood will look like before, during and after a typical open-cut project. In some areas, the contractor will use tunneling to avoid major traffic implications.

With any type of construction, residents can expect to see and hear heavy equipment during the sewer excavation process.

Traffic and Access: As much of the construction will take place in the street, residents should expect temporary lane closures on Des Peres Avenue, Warson Woods Drive, Glen Elm Drive, Glenway Drive, Alexandra Avenue, Alexandra Drive, Belson Court, and Brownell Avenue. MSD Project Clear will maintain at least one lane of traffic at all times to allow property owners to enter and exit. Traffic control will be provided as needed.

Similarly, construction may lead to temporarily limited access to some properties along the construction route. Restrictions will be limited to active construction hours, and the contractor will notify property owners in advance of any access restrictions.

Restoration: After all new sewer pipes are installed, the contractor will restore the construction site according to all MSD and local requirements. This could include sodding any disturbed areas, replacing disturbed pavement, reinstalling fences, etc.

At least one MSD Inspector will be on-site part of the day for every day the contractor is working.

What is the timeline?

This is the current tentative project schedule. This is subject to change based on a variety of factors, including weather.

  • Estimated construction start: January 2024
  • Estimated construction duration: 22 months


Generally speaking, no. Some properties’ connections to the existing public sewer will need to be rebuilt to provide a new service connection to the new sewer. Those properties will experience a brief (typically a few hours) interruption in sewer service as the new connection is made. During this time, those property owners will need to refrain from high-water use activities. Advance notice of the interruption will be provided.

In accordance with MSD policy, the Contractor will restore all disturbed surfaces to previous or better conditions.

The Contractor will be committed to minimizing any instances of access issues to residential or commercial property. It is expected that there will be instances of temporary access issues to both commercial and residential properties. Once the Contractor is selected, they will provide notice to residents before their properties are affected by construction.

The District will be removing and replacing portions of the sewer and abandoning other portions in place depending on the accessibility to the current system. There will be other portions of the existing sewer system that will remain and be used in place.

Depending on where the crew is working the equipment will stay next to the open trench within the easement limits or in the street right of way. When the crew moves from one reach to the next, they might stage the equipment at a specific location before work starts on that next reach. During normal operation, the equipment will not be moved on a nightly basis.

Typically, construction of a gravity sewer starts at the downstream end. The downstream end in this project is the North end of the project near the manhole by Old Warson Rd. The Contractor will then proceed upstream, in this case moving South.

Yes. As a part of easement negotiations, MSD will provide the property owner an opportunity to specify what type of sod they would like replaced. In locations where easements already exist, MSD will attempt to identify the already existing sod in order to match it after construction. Wooded areas that are not maintained are typically not sodded.

Since this is an extensive project that will take time, there are no plans on closing the entirety of this stretch of Warson Woods Dr for the duration of the project. However, there are times that there will be temporary full closures on parts of Warson Woods Dr in order to construct the sewer. More specific information on locations and timings will be provided once the Contractor is selected and they develop a Traffic Control Plan. However, the Contractor is required to maintain full access for emergency vehicles at all times.

During the construction process, as the Contractor gets closer to properties, they will leave door hangers and/or send letters of notification to each property that will be affected at that time by construction. Typically, these notifications are provided 2 weeks prior to work being done.

This project deals only with improving the wastewater system. MSD does not currently have a funding source to legally address overland flooding.

MSD’s Operations Department will review each SSP as a part of the construction process. On a case by case basis, they will determine whether or not it would be effective to leave the SSP in on each specific property.

The Contractor is required to control erosion throughout the duration of the project. The specific means and methods will have to be approved by MSD and those details will be available once construction begins. Additionally, this project is large enough that it will require a Stormwater Pollution Prevention plan to be developed prior to construction.