CSU researchers develop tool to help cities make better stormwater management decisions

The CLASIC tool works with GIS to make it easy for users to explore stormwater management options for a selected area.
The CLASIC tool works with GIS to make it easy for users to explore stormwater management options for a selected area.

Researchers at Colorado State University’s One Water Solutions Institute have developed a tool that assesses stormwater control measures for a selected municipal area, giving decision-makers a holistic analysis of cost, performance and benefits in minutes.

A freely accessible and user-friendly web tool, the Community-enabled Lifecycle Analysis of Stormwater Infrastructure Costs tool, or CLASIC, allows users to explore different scenarios for managing stormwater and estimates the cost over a project’s lifetime. Stormwater professionals, community planners and local decision-makers can weigh the outcomes based on their community’s priorities.

“The CLASIC tool is designed to help inform decisions on extent and type of stormwater technologies to add into an area to achieve hydrologic and water quality targets,” said Sybil Sharvelle, a professor in the Department of Civil and Environmental Engineering who led CLASIC’s development with Professor Mazdak Arabi and Tyler Dell, former director of the Colorado Stormwater Center. “It also provides information about life-cycle costs and potential co-benefits associated with those particular stormwater technologies.”

WRF CLASIC IllustrationInvesting wisely

Green stormwater infrastructure practices offer many benefits, but because they require an initial higher investment, cities can have a hard time justifying the cost in their budgets. The Environmental Protection Agency funded development of this tool to give utilities a way to understand the overall costs of sustainable practices compared to their long-term benefits.

“A lot of cities see risk in not understanding what the maintenance costs are, but we were able to collect data on maintenance of these practices and estimate long-term cost,” Sharvelle said.

CLASIC uses geographic information systems (GIS) to characterize a selected area, so the user doesn’t need to input this data to complete their analysis. It also prevents the need for a community to hire a consultant or task their staff to do this kind of comprehensive analysis before making decisions on stormwater projects.

Nine case studies conducted for cities across the U.S. are documented on CSU’s eRAMS website, demonstrating the many ways CLASIC can aid stormwater project planning – from investigating a combination of gray and green infrastructure to projecting performance in future climate scenarios.

Going green

Urban runoff flowing into our waterways can degrade water quality and cause erosion, especially during peak flows from storms. Sustainable stormwater control measures can restore our systems to a more natural hydrology and infiltrate stormwater into groundwater, recharging local sources.

Sharvelle expects CLASIC will make it easier for cities to choose green infrastructure, once they see the enhanced performance and benefits that result from the higher upfront cost.

“I hope many cities across the United States use this tool and implement stormwater control measures like green infrastructure and low-impact development technologies, which have so many benefits,” Sharvelle said.

The Water Research Foundation managed the EPA-funded project that produced CLASIC, and Geosyntec Consultants, Water Environment Federation, Wichita State University Environmental Finance Center, Wright Water Engineers Inc., University of Maryland Environmental Finance Center and the University of Utah all contributed to the tool’s development, led by CSU.