Throughout the years, the Green #4 Consolidated Drain Drainage District has experienced frequent and longstanding flooding at several locations, including backyards, basements, parking lots, and the intersection of Holt and Aurelius Roads. These flooding events were occurring as often as once a year.
This flooding was happening for several reasons. Over the years, ongoing development within the drainage district included houses, driveways, roads, parking lots, and buildings. This development decreases the amount of water that can infiltrate into the ground and increases how much water enters the storm sewer system. Those developed areas are considered impervious and they now cover more than 40% of the drainage district.
The storm sewer system was constructed as development occurred. The storm sewer system was pieced together without increasing the main outlet pipe size and capacity. This means that more and more water is trying to use the same sized pipe.
Within the watershed, there is also a lack of storm water detention storage. Stormwater detention storage refers to intentional areas where rainwater runoff can stay for a limited amount of time before entering the groundwater or storm sewer system. When there is a large amount of rainwater runoff, it flows directly into the storm sewer system. When the storm sewer system becomes full, the excess water overflows into low-lying areas within the district, flooding them.