Coralville Flood Mitigation Study
- Local Governments
- Sustainability + Resilience
- Water + Wastewater Planning
- Water Resources
- Coralville, Iowa
The City of Coralville requested a major flood mitigation study for flood-prone areas during 2008, which included Biscuit Creek, Clear Creek, and the Iowa River. The report outlined a plan and supporting data to assist with funding applications for construction. The scope of the study was to develop alternatives and recommendations for a flood control plan with probable estimates of construction costs. The report provided the City with a plan and supporting data to assist with funding applications for construction.
The City was successful in obtaining over $50 million of I-JOBS and CDBG funding. The City hired HR Green for the design of specific flood control improvements based on the flood mitigation study. The timeline for the design was extremely tight, as the City wanted to get the I-JOBS and CDBG money into the local construction economy as quickly as possible.
Construction projects included the following improvements:
- Modifications to four existing stormwater pump stations to raise electrical instrumentation and controls, restore power, and replace and repair damaged equipment and screens
- Complete reconstruction of two existing pump stations
- Six new pumping stations with 50-cfs to 220-cfs pumping capacities, automated fiberglass sluice gates, and a diesel generator emergency power supply
- Storm sewer gate closures
- Reconstruction of the 1st Avenue Bridge over Clear Creek, incorporating removable floodwall closures at the bridge and in the Iowa River Landing area
- Earthen levees from Iowa River Landing to East 7th Street
- Utility relocations (electrical, sanitary, fiber optics, storm, water, gas, and cable)
- In-stream retention basins
HR Green also provided construction administration and observation, detailed project documentation, including quantity measurements, daily work reports, pay estimate reviews and contract modifications; leading construction progress meetings; and coordinating a final review of the projects with the contractor and City.