Overland Flow Routes and Drainage
Reducing Flooding from Urbanization
The Village of Tinley Park’s Public Works Department maintains more than 240 miles of storm sewers, as well as the numerous detention basins that support them. The detention ponds are linked together to convey stormwater to each of the six streams flowing through the Village. To reduce flooding that would otherwise result as part of the urbanization process, as well as to assure efficient use of stormwater storage areas and simplify and assure better maintenance of the system, the Village enforces a central detention ordinance.
How the System Works
The Village’s stormwater drainage system is composed of two systems: a major system and a minor system. The two systems work together to prevent flooding of homes and roadways.
The major system is the overland flow route, which consists of surface drainage swales, paved roadways and detention basins. Each subdivision is designed to convey runoff from heavy rains to a detention basin, where the water can be detained and slowly released. The minor drainage system consists of storm sewers, catch basins and inlets. This system also conveys stormwater runoff to detention basins.
However, the minor system is not designed to convey the entire runoff from a 100-year storm. The minor system transports runoff from small rain events, as well as a portion of the runoff from the large storms, to the detention basin. When the minor system is not functional due to collapsed pipes or blockages in the pipe, or the amount of runoff exceeds the capacity of the storm sewer, the major system takes over.