Development of Continuous Radar Rainfall for Sewer System Modeling (1999-2011) for Columbus Ohio

A rainfall library covering 13 years with 5-minute interval rainfall data was developed for the City of Columbus, Department of Utilities, Division of Sewerage and Drainage (DOSD) to support continuous modeling of CSO and SSO and other sewer system analysis, including analysis of spatial trends to characterize the pattern of precipitation produced by storms traveling across the service area. Modeling the collection system required realistic rainfall patterns with near continuous coverage from 1999-2011, a period during which flow monitoring data was also available (City of Columbus, 2012). To reduce sewer overflows and to develop long-term capacity planning, the powerful combination of representative rainfall with flow monitoring is helping Columbus prepare for their new direction in wet-weather system planning. Rainfall-derived inflow and infiltration (RD/II) determination and continuous hydrologic/hydraulic modeling will be aided by spatially variable rainfall data that helps identify capacity problems associated with wet-weather in the City of Columbus.