Retention vs Detention

The City Council in Aiken, South Carolina is considering construction of a new retention or detention pond on a roughly 5.5-acre plot of land that takes drainage from two roads and to head off flooding of an area of the city. The city must decide upon either a dry detention pond that would focus on infiltration back into groundwater or a retention pond that would utilize a liner or partial liner and keep a steady level of water in the pond (approx. 3 feet) with a design capacity of 6 to 8 foot depth. The latter approach would enable development of the pond’s surrounding area for trails and park land.