McKenna Blvd. Flood Mitigation Project
Latest Update
9/30/2021 Update:
This project is complete.
Project Overview
The City of Madison's West Badger Mill Creek - Elver Park Greenway is a channel that carries stormwater from as far north as the Beltline, through Greentree Pond, and under McKenna Boulevard to the pond in Elver Park. Many homes and businesses are located directly adjacent to this greenway, including homes located on cul-de-sacs along Park Edge Drive, multifamily homes in the vicinity of Schroeder Road, and residential and commercial area along Struck Street. Since 2016, Park Edge Drive residents have experienced several rain storms where water from the greenway flooded the neighborhood and entered their homes. This impact was most severe in August 2018. Additionally, McKenna Boulevard, which is a main thoroughfare through the neighborhood and houses police and fire stations for the west side of the City, has overtopped and become impassible several times. During flooding in August 2018, several properties along Struck Street also experienced inundation and a senior apartment and assisted living facility needed to be evacuated.
In response, City Engineering designed and constructed a public works improvement project to mitigate the recurring flooding in this neighborhood, on McKenna Boulevard, and along Struck Street.
Phase 1
Construction of Phase 1 was completed between July 2019 and May 2020 and included the following improvements
- Three existing pipes under McKenna Boulevard were removed and replaced with two 5’ tall by 10’ wide box culverts and two 5’ tall by 12’ wide box culverts, which greatly increased flow capacity under the road. This work included constructing new inlet and outlet wing walls.
- Existing concrete channel was removed and replaced with a new concrete channel 1.5 feet lower than its previous level.
- A retaining wall was constructed along the west edge of the greenway to provide significantly improved flow capacity in the channel that runs adjacent to Greentree Landfill.
- Existing metal pipes at the outlet of Greentree Pond were removed and replaced with two 4’ tall by 8’ wide box culverts. The pond outlet and channel were also realigned to point southwest, rather than west, to prevent flows from going directly towards the back side of homes on Falmouth Court.
On December 13, 2018 the City hosted a Public Informational Meeting held at Our Redeemer Church on McKenna Blvd. A copy of the presentation can be found here. Staff discussed the flooding that occurred in June and August of 2018, design standards, watershed modeling, and the proposed public works contract.
All aspects of the design can be found in the final plan set for the project, here: Final Plans
![The image shows the newly constructed box culverts under McKenna Boulevard. There are two 5-foot by 10-foot culverts and two 5-foot by 12-foot culverts.](/engineering/images/projects/McKennaCulverts.jpg)
Phase 2
Construction of Phase 2 was completed between June 2020 and August 2020 and included the following improvements:
- Existing metal pipes at the inlet of Greentree Pond were removed and replaced with four 42” concrete pipes. The new pipes have invert elevations 1.5’ lower than the old pipes.
- The natural channel between Greentree Pond and Schroeder Road was excavated to be 1.5 feet lower than the old channel.
- Three existing pipes under Schroeder Road were removed and replaced with two 4’ tall by 8’ wide box culverts, which have capacity to carry the 1% chance storm without overtopping onto Schroeder Road. These culverts were realigned to discharge south-southwest, away from the mixed use path, and the new culverts were set 1.5 feet lower than the old pipes.
- The Schroeder Road profile near Struck Street was reshaped to create a low point that better facilitates street drainage.
- Existing concrete channel was removed and replaced with a natural channel that is lower than the old channel and has a 2’ deep pool of standing water.
Phase 2 was analyzed together with Phase 1 as part of the design process to ensure that both phases work together to meet the flood mitigation goals for the entire stretch of greenway that extends south to Elver Park. All aspects of the design can be found in the final plan set for the project, here: Final Plans
![This image shows the newly reconstructed channel. There is a low flow concrete channel with a grassed area on one side and a retaining wall on the other.](/engineering/images/projects/McKennaChannel.jpg)
Project Limits
Street construction at Schroeder Road-Struck Street intersection and 300 feet to the west along Schroeder Rd. (complete); channel construction along greenway from Greentree Pond to 800 feet north of Schroeder Rd. (ongoing).
Project Schedule
Phase 1 Schedule
Permit application approval: May 2019.
Bid opening: June 2019
Contractor selection: June 2019
Construction began: July 2019
Phase 2 Schedule
Permit application approval: January 2020, May 2020.
Bid opening: April 2020
Contractor selection: April 2020.
Construction began: June 2020
Scheduled completion: August 2022
*During construction there was a full closure of Schroeder Road at the intersection with Struck Street for the duration of the project. Metro service on Struck Street and Schroeder Road, between Gammon Road and Rayovac Drive, was detoured along Watts Road and Rayovac Drive during construction. Bus stops at the corner of Struck St. (SB) & Watts Rd., Schroeder Rd. (EB) & Struck St., and Schroeder Rd. (EB) & Chapel Hill Rd. were temporarily closed during construction. All bus stops located Watts Road and Rayovac Drive remained open for the Metro service detour.
Public Involvement
There are a number of points of contact during this project where the public was encouraged to give feedback as part of public information meetings and public hearings. Dates and times are indicated below:
Public Information Meetings
Dec. 3, 2018 Public Information Meeting PowerPoint Presentation
City Meetings, Process
Board of Public Works: March 4, 2020
Common Council: March 17, 2020