The Bay County Land Development Code regulates new developments within the county. Included in the provisions of the land development code are stormwater quality and quantity criteria. Stormwater quality refers to ensuring the quality of the stormwater runoff prior to the water exiting the development site. The land development code requires new developments to meet the criteria as established by the Florida Department of Environmental Protection and U.S Army Corp of Engineers. Specifically, the Bay County Land Development Code governs the quantity of stormwater generated by a development.
New developments are required to control their stormwater runoff through attenuation measures. Attenuation requirements include the stipulation that a development cannot release more stormwater than was released before the development occurred for the 25-year rainfall event. Attenuation is generally provided by retention/detention basins or other means of storage.
(As a side note: The 25-year rainfall event produces a quantity of precipitation that will fall over time based on a 100% probability that a rainfall event of this specific volume and duration will occur every 25 years. Because a 25-year rainfall event occurs this year does not mean there will not be another rainfall of this magnitude for another 25 years. There is a 4% probability that a 25-year event will occur in any given year and a 100% probability that at least one 25-year rainfall event will occur every 25 years.)