Boulder County outlines major flood mitigation plans for South Boulder Creek and Gregory Canyon

The Water Resources Advisory Board meeting held on June 18, 2025, in Boulder City, Colorado, focused on several significant storm and flood utility projects aimed at improving the region's flood management capabilities.

The meeting began with a detailed discussion on the South Boulder Creek Phase Flood Mitigation Project. This project, which has been in development for an extended period, includes the construction of an earthen dam and a concrete flood wall along US 36. The projected cost for this initiative is approximately $66 million, with plans to finalize bid documents and permits in the coming weeks.

Next, the board addressed the Gregory Canyon Creek Project. This project aims to enhance flood management in a densely developed area, running from the confluence of Boulder Creek to Pennsylvania Avenue. The design is focused on accommodating a 25-year storm event, a significant upgrade from the current capability, which is only sufficient for a 5-year storm. The discussions highlighted the challenges of retrofitting older urban areas to meet modern floodplain regulations while considering the impacts of climate change.

The final project discussed was the Upper Goose Creek initiative, which combines flood and stormwater management strategies. This project aims to address localized flooding issues experienced during storms, particularly in North Boulder Park. Construction is anticipated to begin in 2028, with a focus on increasing capacity to manage stormwater flows without adversely affecting downstream areas.

The meeting concluded with a mention of a $500,000 funding allocation for projects in 2026, emphasizing the ongoing need for financial support to maintain and improve the region's flood management infrastructure. The discussions underscored the importance of proactive measures and community preparedness in the face of increasing flood risks.