Project Overview

The South Boulder Creek Flood Mitigation project is part of the City of Boulder's efforts to minimize the damaging effects of a major flood. Along with the University of Colorado-Boulder, Open Space and Mountain Parks, the Mile High Flood District and Colorado Department of Transportation (CDOT), the city staff has worked to identify the best flood mitigation option.

South Boulder Creek Fact Sheet 101

Background and Purpose

There are an estimated 600 structures and 3,500 people in the South Boulder Creek floodplain within city limits. Flood mitigation studies have looked at several locations along the creek and through extensive public feedback and analysis, found the best location for flood detention was near US-36 on property owned by the University of Colorado-Boulder.

The purpose of flood mitigation, or lessening the damaging effects of a flood, is to provide protection for community members and major utilities and transportation infrastructure including US-36 and Foothills Parkway, while being the least impactful to open space. Since City Council approved the plan in 2015, city staff has been working collaboratively with CU-Boulder and the Colorado Department of Transportation (CDOT) in developing flood mitigation options for the area that will impact 2,300 community members, 260 structures and 1,100 dwelling units.

Over the last 80 years, South Boulder Creek has flooded significantly six times, with overtopping of US-36 happening in 1969 and 2013. As a result, the city has been working to mitigate future flood impacts over the last decade. Learn about major milestones in the South Boulder Creek Flood Mitigation project. Review past milestones here.

Latest Updates

Staff will present the updated design to the Open Space Board of Trustees in late fall of 2023.

Staff presented the environmental mitigation alternatives to the Open Space Board of Trustees on Jan. 11, 2023

Staff completed the preliminary design documents and provided an update to City Council on April 19, 2022.

The design team has completed a baseline groundwater model to represent the existing groundwater conditions in the area. The Baseline Groundwater Report was discussed at the Open Space Board of Trustees meeting on December 1, 2021.

Lynker Technologies completed a report on the state of climate science to inform the flood mitigation design process. View the report.


University of Colorado - Boulder:  CU South Annexation project webpage.

Mile High Flood District: Learn more here: MHFD.