Willow Creek Watershed Study
The proposed flood mitigation measures are being developed for the watershed. Once they are complete, and have undergone internal review, the third Public Information Meeting will be scheduled.
Complete a survey to help City Engineering prioritize flooding improvement projects.
The City of Madison will be completing a watershed study in the Willow Creek watershed (as shown below). The watershed study will identify causes of existing flooding and then look at potential solutions to try to reduce flooding. The study will use computer models to assist with the evaluations. In April 2020, the City of Madison Engineering Division contracted with MSA Professional Services to complete the watershed study and report, including an existing and proposed conditions analysis.For more information please see the Flash Flooding Story Map. *Note: Please view the story map using Firefox or Google Chrome browsers. Story maps are not viewable with Internet Explorer.
The watershed drains to the north to Lake Mendota through Willow Creek, which runs through the University of Wisconsin - Madison campus.
The project is scheduled to kick-off in late April 2020. The estimated time to completion of the study and report is approximately 18 months.
There are a number of points of contact during this project where the public is encouraged to give feedback as part of public information meetings and public hearings. Dates and times are indicated below:
Public Information Meetings
- March 10, 2021 Public Information Meeting Recording
- March 10, 2021 Public Information Meeting PowerPoint Presentation
- Sept. 17, 2020 Public Information Meeting No. 1 PowerPoint Presentation
The City of Madison has 22 watersheds. Watersheds are an area of land that drain to the same location (the outlet).
There is a stormwater drainage system in all watersheds. This system is what conveys the stormwater to the outlet of the watershed. The City of Madison's stormwater drainage system includes approximately:
- 570 linear miles of stormwater pipes
- 42,800 stormwater inlets and access structures
- 250 stormwater ponds
- many miles of open greenways, channels and ditches
- many stormwater infiltration areas.
The City's system dates back to the 1880s. Very few, if any, standards were available in the 1880s. As the City developed, so did the guidance for design and construction. Today, we have comprehensive City, State, and Federal regulations to guide design and construction. The area of the City you live in used the regulations in place at the time it was developed. You can view the StoryMap to see what the regulations were for your neighborhood.
The extreme storm events in 2018 shed light on the deficiencies of the City’s stormwater drainage system. Many areas of the City experienced devastating flooding. This prompted the City to begin a comprehensive watershed study program in 2019. The intent of the program is to study each of the City’s watersheds one-by-one. The studies will help us to understand the causes of flooding. The studies will also provide recommended solutions to reduce the risk of flooding.
The watershed studies result in a list of proposed mitigation measures. Once constructed, the measures will reduce the risk of flooding to specific areas of the City. These mitigation measures are generally very costly. Due to limited stormwater management funding, all the mitigation measures cannot be implemented at one time.
The average Stormwater Utility Capital Budget each year is approximately $12 million. Within that, an average of about $2.4 million is used for flood mitigation. As of late 2021, recommended flood mitigation measures for the first five watershed studies were identified. The total cost from the first five studies is approximately $125 million. We expect the remaining 17 watershed studies will have similar flood mitigation project needs. Implementation of these flood mitigation measures will take many decades.
The Stormwater Utility funds the stormwater management for the City. This includes the construction, operation, and maintenance of the entire stormwater drainage system. The Stormwater Utility rates are set each year consistent with Wisconsin Statute. § 66.0821(4) and as described in Madison General Ordinance section 37.05 . These rates are under the purview of the public service commission. The rates are required to be deemed “reasonable” to comply with state statute. During the annual budgeting process, the City tries to balance the stormwater needs with the stormwater rate charged to its customers. These needs include:
- Implementation of flood mitigation measures
- Replacement, extension, and upgrades of existing the existing stormwater system
- Mandated water quality needs and requirements
When possible, the City attempts to get grant funding to partially fund the flood mitigation measures. Grant funding makes up a small part of the funding needed for stormwater management.
The City has created a draft prioritization process. This process creates a proposed order to construct the flood mitigation measures. This process accounts for many factors including:
- Impact on emergency services,
- Location of vulnerable populations,
- If the project also improves stormwater quality,
- Whether other projects are occurring nearby, and
- If outside funding is available.
- City of Madison Flood Website
- Flash Flooding Resilience Story Map *Note: Please view the story map using Firefox or Google Chrome browsers. Story maps are not viewable with Internet Explorer.
- Watershed Frequently Asked Questions
- 2020 Engineering Waterways Newsletter
- Watershed Studies 2019 Audio Presentation
- Flood Prevention Flyer and website
- LISTEN: Everyday Engineering Podcast Episode: Basement Drainage
- LISTEN: Everyday Engineering Podcast Episode: Historic Flooding
- LISTEN: Everyday Engineering Podcast Episode: What's going on with the Watershed?
If anyone has experienced flooding, and is willing to share with the City, please report it on the City's website. Even if a homeowner reported flooding to 2-1-1, FEMA, or a City official, the City needs standardized information to create stormwater models that show existing flooding conditions. The flood data helps the City prioritize different flood projects and future watershed studies. Please report any flooding you’ve experienced.