Buffalo Street Stormwater Drainage Study
The City of Warsaw had been experiencing localized flooding in one of the City’s main parks, Central park. An existing 36-inch storm sewer in the City’s stormwater collection system, was originally designed to convey stormwater to the existing Osborn Street Lift Station from major portions of the City including the Central park area. There is also a small stormwater overflow pump station in Central park. The existing 36-inch storm sewer begins near the railroad tracks east of Detroit Street and continues west through Central Park, across Buffalo Street and then flows northwest adjacent to Center Lake to the Osborn Street Lift Station. Based on pump run times and water level observations, the City determined that there were blockages in the existing 36-inch storm sewer west of Central Park due to root intrusion (i.e. root balls) at pipe joints.
The City requested that American Structurepoint evaluate the existing conditions and develop alternatives to alleviate the flooding problem in the park by providing positive drainage for the capacity the storm sewer can deliver. Additionally, the City requested that Structurepoint evaluate what should be done with the existing 36-inch storm sewer where it crosses Buffalo Street. There is a significant proposed development along Buffalo Street currently in the planning stages that includes a gravity sanitary sewer that will flow north to a proposed sanitary lift station. The final recommendation was the replacement of the existing 1,000-gpm Central Park Lift Station with a 5,000-gpm lift station. The gravity relief line reduces the capacity available from areas upstream of the Park at higher Lake Levels, but is the most economical option for improving system performance by utilizing gravity conveyance in lieu of pumped conveyance. In addition, the recommendation including running all system flows through a BMP to reduce sediment to both the Lake and the 36-inch pipe which has several sags.