Floodplain Management

Floodplain Management and Flood Mitigation

In July 1997, record localized rainfall at the west side of Fort Collins resulted in severe flooding that swelled Spring Creek, killed five people and caused millions of dollars of damage. During that rainstorm, flood waters sheet-flowed onto CSU’s Main Campus, traveled through campus to the east flooding buildings and causing approximately $150 million in damage. After the recovery efforts, CSU renovated damaged buildings and constructed floodwalls, berms and below-grade storm systems to provide improved flood protection to the University. Since 1997 the University has invested over $5 million in flood mitigation measures and drainage improvements.

The University’s Main Campus Master Drainage Plan has been routinely updated since the ’97 flood, and depicts a 100-year floodplain that could develop during in a 100-year storm event. The 100-year floodplain map is shown below, a link to a .pdf version can be found here Adobe Reader Document (PDF) Flood model videos can be found here and here.

CSU maintains a goal of reducing flooding risk through structural and non-structural flood mitigation measures. Structural measures include flood-proofing structures in the inundation area, constructing detention ponds and diverting floodwaters without causing adverse impacts upstream or downstream. Non-structural measures include education, planning and design considerations. Design of projects within or touching the floodplain must undergo hydraulic modeling and review by Facilities Management so that there is not a “rise” in the water elevations shown, nor a change in the flow path that adversely impacts another campus feature.

If you are involved with a construction project of any type that is in or touches the floodplain, please contact your CSU Project Manager or the Campus Landscape Architect to make sure you are implementing the appropriate steps for flood risk mitigation.