CASE STUDY: GRANT STREET PUMP STATION FLOOD MITIGATION IN A WEST ALLIS, WISCONSIN NEIGHBORHOOD

The Milwaukee Metropolitan Sewerage District (District) has permissive authority to provide protection from over bank flooding from watercourses within its jurisdictional boundaries. Flood mitigation within urban centers presents challenges due to the limited available land and costs associated with work in a developed area. To be successful, alternatives identification and evaluation must address technical issues (hydrologic and hydraulic modeling and economic considerations in a densely developed area) and the need to involve the stakeholders throughout the evaluation process. This paper presents the process for alternatives identification, stakeholder involvement, evaluation, and remedy selection and a description of the selected alternative for mitigation of localized flooding in the city of West Allis, Wisconsin. The situation in the West Allis project area is typical of many urban settings in the upper Midwest, resulting from the previous practice of allowing development without adequate stormwater control requirements and the general flat terrain typical of the Milwaukee, Chicago, and Rockford areas. The constraints of the urban setting, and the need to consider environmentally sound remedies that will not degrade the existing watercourse, required an innovative approach to meeting the project objective. In addition, the project team was able to provide relief for localized stormwater problems as part of the project.