All areas adjacent to streams have a defined or implied floodplain. Within this floodplain, development is restricted and regulated.
In the 1970s, the Federal Insurance Administration (FIA) conducted detailed studies of many flood-prone waterways. These studies were significantly revised in 2007. If such a study was done, the floodplain is delineated on an official floodway map that indicates the stream channel, “500-year” and “100-year” floodplains. In the absence of such a study, the floodway is defined as the area including the stream channel and 50 feet landward from the top of the stream bank on both sides of the stream channel.
The National Flood Insurance Program (NFIP) is a federally based insurance program for property owners in flood prone areas. The NFIP is based on a mutual agreement between the federal government and the community. Federally subsidized flood insurance is available in those communities that agree to regulate development in their designated floodplains. The NFIP requirements provide the minimum basic guidelines for state and municipal regulations governing floodplain management and development. If the communities comply with the NFIP floodplain development criteria, federal flood insurance can be purchased for properties in the community.
Community adherence to these floodplain regulations is reviewed on an ongoing basis. If the community is found to still be adhering to the regulations, insurance rates stay the same. If the community is found to be in violation of the regulations, the insurance rates for all policy holders may go up or flood insurance may no longer be offered through the NFIP.
It is possible that you will need to demonstrate compliance to your community’s floodplain management ordinance before a building permit will be issued.
It is in the interest of all property owners within the floodplain to keep development and land usage within the scope of the floodplain regulations for their community. This helps keep insurance rates low and makes sure that the risk of flood damage is not increased by development of a property near yours.
These floodplain management regulations establish guidelines to make sure that development and land usage within the floodway and adjacent floodplain does not make flooding worse for everyone within the floodplain. The guidelines are used to prevent the creation of additional obstructions to flood waters and prohibit land fill that would divert excessive flood waters onto adjacent properties.
The floodway management regulations and Flood Insurance Rate Maps (FIRMs) were developed by the Federal Emergency Management Agency and copies are available either from them, PA DCED, or your municipal or county planning commission.