Grassy Creek Stormwater Master Plan Tackles Neighborhood Flooding

Grassy Creek runs through the heart of the City of Perrysburg, Ohio. The area south of the creek has sanitary sewers and some stormwater infrastructure. This neighborhood faces existing stormwater challenges, including frequent and prolonged flooding. 
 
The Grassy Creek Stormwater Master Plan project initiated with a data review and an initial public meeting to gather information from the residents regarding locations and frequency of flooding in the neighborhood. Flooding complaints in the neighborhood were frequently referring to backyards. To simulate backyard flooding a 2D SWMM model was developed and linked to the stormwater drainage infrastructure and Grassy Creek to understand drainage and flooding extents. Local stakeholder experience and feedback was critical to confirmation of the model predictions. 
 
Perrysburg prefers alternatives that minimize maintenance and encourage elimination of water from the sanitary sewer system. Alternatives evaluated included encouraging neighborhood stakeholders to take advantage of programs that remove sump pumps from the sanitary system, utilizing existing oversized infrastructure for underground storage of stormwater, and implementation of green infrastructure to promote infiltration but with plants such as turfgrass that can be mowed by the residents. Citizen concerns regarding creek flooding led to further alternatives to relieve stormwater pressures on the creek, redirecting flow to the nearby Maumee River. Ongoing contact and coordination with the residents were critical to the success of the project.
 
The suite of alternatives was modeled, and several levels of service were analyzed along with cost for the various alternatives. The final recommendation focuses on how the backyard and creek flooding can be reduced by fully utilizing existing infrastructure, installation of new infrastructure, encouraging participation in city programs, while keeping ongoing maintenance costs to a minimum.