Rainfall has been trending toward shorter duration and higher intensity events, often resulting in flash flooding, even when the rainfall amount is relatively small. This has posed significant threats to community drainage systems for the north central area of Storm Lake. The North Central Stormwater Improvements project was designed to relieve substantial overland flooding from approximately 150 acres of developed watershed consisting of residential and school property.
Bolton & Menk developed a stormwater relief and treatment solution that was cost effective, environmentally sensitive, and adaptive to future flooding. Comprehensive hydraulic modeling of the existing drainage system was completed to generate a set of tools used to prioritize improvements.
A unique treatment train concept was designed that diverts stormwater runoff from the main drainage channel into linear bio-treatment basins in lieu of traditional pipe conveyance. This cost-effective concept reduces infrastructure costs, provides significant regional flood control, and reduces pollutant loading to Poor Farm Creek. A benefit is added green space within the community.
The City of Storm Lake was one of the first communities in the state to participate in the State of Iowa Homeland Security funding program (Flood Mitigation Funds) to meet water quality improvement requirements. The success of this first phase of the project led to receipt of 75 percent funding for a second phase.
American Council of Engineering Companies of Iowa – 2017 Engineering Achievement Award
1000 Friends of Iowa – 2016 Best Development Award: Stormwater-Civic