Project Overview

Wonderland Creek begins at Wonderland Lake in north Boulder and has a tributary watershed area of approximately two square miles. The creek flows southeast through the city to its confluence with Goose Creek near Pearl St. The creek flows primarily through residential development.

Wonderland Creek Channel Improvements

The City of Boulder is partnering with the Mile High Flood District (MHFD) to conduct channel improvements to Wonderland Creek between 19th St. and Sumac Pond. The purpose of this project is to reestablish a low flow channel and to construct improvements needed to separate the Githens irrigation lateral from the Wonderland flows near Sumac Pond.

MHFD has procurred Drexel, Barrell & Co. to conduct pre-project surveying. To accommodate this survey, some community members may receive a request from Drexel, Barrell to access survey locations via private property. All work will be performed within existing city easements.

Once survey has been completed, MHFD will begin the preliminary design phase for this project. Construction is anticipated to occur in the winter 2021/2022.

Winding Trail to Foothills Parkway

Wonderland Creek project construction began in January 2016 and was completed in April 2019. The project extends from Foothills Parkway in the south to Winding Trail Drive in the north. The purpose of this approximately $30M project (cost includes design and construction) is to provide channel improvements for this segment of the creek to contain the flows associated with the 1% annual chance flood (aka 100-year floodplain). By creating these improvements, the city will be reducing the flood risk to numerous structures and dwelling units that are currently located within the 1% annual chance special flood hazard area floodplain. In addition, we will be building three new underpasses (1. at the BNSF Railroad 2. Kalmia Ave. 3. 28th St.) to provide safe passage for pedestrians and cyclists as we extend the multi-use path system from Foothills Parkway to 30th St. In order to create these new features, approximately 450 trees have been removed along the project reach. 1,884 new trees and shrubs were replanted.

Current Remapping Process

The city has completed the Letter of Map Revision (LOMR) comments and have submitted the LOMR maps to FEMA. Notifications to affected parcel owners were sent out in Sept. 2020. The city cannot anticipate how long the LOMR will take for FEMA review (on average, remapping can take approximately 9-18 months to complete) Once the city receives notification from FEMA on the approval of the revised mapping, the city will send out letter notifications to all properties in the Special Flood Hazard Area to inform community members of the new effective date of the revised Flood Insurance Rate Map.

Check out the video presented at the 2019 Colorado Association of Stormwater and Floodplain Manager's annual conference

Wonderland Creek at 19th St.

The City of Boulder's Transportation Department is currently in the design phase for improvements to 19th Street. Modifications to the Wonderland Creek culvert at 19th Street will be incorporated into this transportation project to assist with future flood mitigation efforts along Wonderland Creek.

Wonderland Creek Mapping and Mitigation Information