Graphical representation of flood inundation for NWS flood categories are based on steady state hydraulic modeling of water surface elevations for incremented discharges. Map shows approximate inundation areas for given water surface elevations and should not be used for navigation or permitting or other legal purposes, but strictly as a planning reference tool.
The purpose of a flood forecast inundation map is to communicate flood risk based on best available information at the time of map development. This flood forecast inundation map has been compiled using the best information available and is believed to be accurate; however, its preparation required many assumptions. Actual conditions during a flood event may vary from those modeled in the map. The limits of flooding shown should only be used as a guideline for emergency planning and response actions. Actual areas inundated will depend on specific flooding conditions.
The risk of flooding behind flood risk management (FRM) structures (such as levees, floodwalls, closures, etc.) depends on many factors that cannot be entirely predicted in advance. These factors include whether the FRM structure overtops, length of time the structure overtops, and whether the overtopping leads to breach formation.
The mapping is based on the PASDA ground elevation data from 2006-2008.
Danville Flood Risk Management (FRM) System (red lines) – At the time these maps were developed (2017), the FRM system was shown as accredited by FEMA on their Flood Insurance Rate Maps, however, it may be freeboard deficient (not have the required height) and more analysis is required. At the request of Montour County, the FRM system is shown on these maps as reducing the flood risk to the area behind it until the system is overtopped. There is a risk that the FRM project may fail prior to being overtopped.
Danville Flood Risk Management Risk Area (yellow shaded area) – Shows areas with flood risk reduced by the Danville FRM system. If the FRM system fails due to any deficiencies, this is the area that would flood.
Mahoning Creek Flood Risk Management (FRM) System (red lines) – At the time these maps were developed (2017), the FRM system needed repair work. The PA Department of Environmental Protection was working towards designing and constructing improvements to the system. At the request of Montour County, the FRM system is shown on these maps as reducting the flood risk to the area behind it until the system is overtopped. There is a risk that the FRM project may fail prior to being overtopped.
Mahoning Creek Levee Risk Area (yellow shaded area) - Shows areas with flood risk reduced by the Mahoning Creek FRM system. If the levee system fails due to any deficiencies, this is the area that would flood.
The detailed project report can be found here
If you have questions related to any of the flood risk management projects in Montour County, call Ed Burkland, Montour County Emergency Management Agency, at (570) 271-3047.