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.

The project aims to enhance the safety of community members and safeguard areas in the city prone to severe flooding from the South Boulder Creek drainageway.

The primary objective is to mitigate the adverse effects of floods, providing protection for community members and crucial infrastructure such as US-36 and Foothills Parkway, while minimizing impact on open space.

Since its approval by City Council in 2015, the city has collaborated with CU-Boulder and the Colorado Department of Transportation to develop flood mitigation solutions for an area affecting 2,300 community members, 260 structures and 1,100 homes.

Updates

  • 2024

The February 2024 Draft Design Report (PDF) is now available. Please reach out to Brandon Coleman to request further materials or the attachments.

Feb. 6 - Planning Board Spillway Annexation. Watch the meeting, or view the agenda and listen to the meeting.

Feb. 15 - City Council Spillway Annexation First Reading

Feb. 22 – Joint City Council and Open Space Board of Trustees Public Hearing on Open Space Disposal

March 5 - Planning Board Public Hearing on Spillway Annexation

March 7 - City Council CU South Wetlands Ordinance First Reading

March 13 - OSBT Deliberations on Open Space Disposal

March 21 - City Council Deliberations on Open Space Disposal, Spillway Annexation Second Reading, CU South Wetlands Ordinance First Reading

  • 2023

Staff updated the Open Space Board of Trustees on the latest design on Oct. 11, 2023. View the agenda and listen to the meeting.

Timeline

  • 1938, 1969, & 2013 Floods
  • 2015 Mitigation plan approved
  • 2017 BVCP Updated
  • 2017-2020 Conceptual Design
  • 2019-2023 Preliminary Design
  • 2024 Final Design
  • 2025-2026 Construction starts

Next Steps

Open Space Disposal – The project requires use of OSMP property for flood mitigation. Use of this property will require approval by city council and the Open Space Board of Trustees through a disposal request.

Spillway Annexation - The project requires annexation of land along Highway 36 to bring the area into the city for flood mitigation work.

Goals

  • The main goal of this project is to mitigate the risk and damage to life and property caused by floods.
  • Reduce high hazard zones and floodplains
  • Create resilience for the future

Methods

  • Avoid, minimize and/or mitigate impacts to the existing ecosystem
  • Repair stream banks
  • Reduce bank sediment by implementing stabilization and natural channel design

Outcomes

Incorporating natural channel restoration into flood mitigation projects can lead to a more vibrant, sustainable and resilient community and environment.

  • Flood Mitigation: Restored natural channels can absorb excess water during heavy rainfall, reducing the risk of flooding in neighborhoods.
  • Property Protection: Stabilized stream banks help prevent erosion, and protect homes and infrastructures located near streams.
  • Improved Water Quality: Natural channel restoration filters out pollutants and sediments, leading to cleaner water.
  • Educational Programs: These projects can serve as educational tools, promoting awareness about watershed health.
  • Community Engagement: Natural channel restoration projects offer opportunities for community members to get involved through volunteer efforts, workshops, and collaborative planning.
  • Environment: This project will avoid, minimize and/or mitigate impacts to the existing ecosystem.
  • Wildlife Habitat: Restoring natural habitats can create homes for diverse wildlife species, enriching the local ecosystem and offering opportunities for wildlife observation.

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 to develop flood mitigation options for the area that will impact 2,300 community members, 260 structures and 1,100 homes.

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.

Project Videos

Rendering of proposed South Boulder Creek Flood Mitigation