The Wonderland Creek Letter of Map Revision (LOMR) has been approved by FEMA. The effective date for the new mapping is March 18, 2024.
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 Street and primarily through residential developments.
The City of Boulder is partnering with the Mile High Flood District (MHFD) to conduct improvements and reestablish a low-flow channel to Wonderland Creek between 19th Street and Sumac Pond.
The Wonderland Creek project was completed in 2019. The project extends from Foothills Parkway in the south to Winding Trail Drive in the north. The purpose of this approximately $30M project was to provide channel improvements to contain a 1% annual chance flood (100-year flood). By creating these improvements, the city has reduced the flood risk to numerous structures located within the 1% annual chance flood area prior to the project. In addition, three new underpasses were constructed (1. at the BNSF Railroad 2. Kalmia Ave. 3. 28th Street) to provide safe passage for pedestrians and cyclists as the multi-use path system was extended from Foothills Parkway to 30th Street.
The city has received approval of the LOMR maps from FEMA. The effective date for the new floodplain map will begin on March 18, 2024. The city will be sending out 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. The effective date is the time when structures formerly in the 100-year floodplain (i.e. their structure was 'removed' from the floodplain because of the mitigation efforts from the project) will no longer carry the federal mandate to have a flood insurance policy associated with the structure - however, flood insurance is always a good idea even if you're not in a formally regulated floodplain.
Check out the video presented at the 2019 Colorado Association of Stormwater and Floodplain Manager's annual conference
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.
The City of Boulder finalized the Fourmile Canyon Creek and Wonderland Creek Major Drainageway Plan in 2011.
