A flood plain is an area of flat land alongside a river. This area gets covered in water when the river floods. Flood plains are naturally very fertile due to the river sediment which is deposited there. In York City this area would be along the Codorus Creek.
The construction, enlargement, or expansion of any structure, or commencement of any activity listed as a special hazard shall be prohibited in a flood plain, unless a special permit has been issued for the proposed construction or activity.
Floodplains are places where water can disperse during floods, which reduces pressure on manmade protection structures like levees and dams and reduces risk for nearby communities. Lower Flood Insurance and Disaster Recovery Costs.
All construction that is allowed in floodplain areas must have the lowest floor elevation at or above the 100-year floodplain elevation. If you have a multi-family or commercial project, you may build in the 100-year floodplain only if your lot complies with all floodplain standards.