By Ryan Stenjem
City of Madison Engineering Division
Early in 2027 the City of Madison Storm Water Utility is planning to begin a significant construction project at Castle Creek on the southeast side of Warner Park. The Castle Creek Improvements Project is the result of recommendations from the Warner Lagoon Water Quality Plan and the Warner Park and Cherokee Marsh Watershed Study.
The design of the channel improvements has several objectives: flood mitigation, water quality protection, and habitat improvements. The project will result in a somewhat different visual appearance to this area in Warner Park; however, improvements to the overall functionality of the stormwater system are expected to benefit nearby residents, wildlife and Warner Lagoon.
The primary intent of the improvement project is to increase the amount of water that can flow through the channel to mitigate flooding on Trailsway and nearby streets. These conveyance improvements support future storm sewer improvements throughout the Brentwood neighborhood, which were identified as part of the Watershed Study. Without the channel improvements first, the sewer upgrades would make flash flooding at Trailsway worse.
Additionally, the project design is intended to improve water quality entering Warner Lagoon by increasing the amount of sediment that is captured before getting to the lagoon and allowing for better access to remove that sediment in the future.
Preliminary design concepts were presented with the Warner Park and Cherokee Marsh Watershed Study public information meeting in September 2025. The Engineering Division is working to refine the design based on additional data collection, including a wetland delineation, topographic survey, and tree condition surveys completed this spring. The proposed improvements include removing the existing concrete section of the channel between the new wooden bridge and the lagoon, as well as lowering and widening the channel.
The widened channel design will slow down flows for smaller storms to allow more sediment and debris to settle in the channel before it enters Warner Lagoon. While many trees will need to be removed to complete the project, the channel modifications have been designed to preserve as many mature, healthy, non-invasive trees as possible. Finally, the area will be restored after construction with native vegetation to provide habitat for native species.
The Engineering Division will gather public input on the project design this summer. Watch for staff at the Parks Alive events at Trailsway in Warner Park and a public information meeting in early August. Check the project website (link below) for updates, and watch for dates for a public information meeting the first week of August.
Note that the Parks Division is also planning to reconstruct the athletic play fields adjacent to Castle Creek in the southeast corner of Warner Park. This project will have separate public outreach and construction, but will be on a similar timeline to the Castle Creek Project.
Additional Web resources:
Castle Creek Improvements Project Website: cityofmadison.com/engineering/projects/castle-creek-improvements
Warner Park and Cherokee Marsh Watershed Study Website: cityofmadison.com/engineering/projects/warner-park-and-cherokee-marsh-watershed-study
Warner Lagoon Water Quality Plan: cityofmadison.com/engineering/projects/warner-lagoon-water-quality-plan
Warner Southeast Recreation Area Reconstruction project Website: cityofmadison.com/parks/projects/warner-park-southeast-recreation-area-development
Project Contact:
Ryan Stenjem
rstenjem@cityofmadison.com
608-266-4913
