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Understanding Local Flood Stage Maps

During the late 1970s through the early 1980s, the Susquehanna River Basin Commission (SRBC) prepared flood stage forecast maps - using a technique the Commission developed - for all or portions of 90 basin communities. SRBC is now preparing maps for additional communities, and updating the existing flood stage forecast maps as necessary.

What is a Flood Stage Forecast Map?

Flood stage forecast maps reflect a range of stream stages that are tied to forecast points such as at Harrisburg and Williamsport. The maps provide details of flood plain areas and flood profiles with water level contours to show and wxplain what areas in a community will be inundated as flood waters reach certain flood stages. It is important that community officials and residents understand what will happen to their community when the basin's waterways are above flood stage, especially since our basin is so flood prone.

SRBC developed the maps using the flood profiles generated for the federal flood insurance program and relate to stream gages operated and maintained by the U.S. Geological Survey. The National Weather Service uses the data from the stream gages to produce a forecast stage at each of these forecast points. Each map identifies the location of the stream gage used in preparing the map.

The maps convert forecasted flood stages, issued by the National Weather Service, into areas of inundation for communities within the map study area. The maps show what the forecast stage levels will look like on the ground.

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Who uses Flood Stage Forecast Maps?

Emergency personnel; to identify areas that will be inundated first; municipal officials to develop flood evacuation plans; and individuals to easily determine how the forecasted flood will affect them.

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What are the benefits of Flood Stage Forecast Maps?

The proper use of a flood stage forecast map can help:

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How are Flood Stage Forecast Maps Used?

Flood stage delineations are placed usually at 5-foot intervals, indicated by contour lines on the map. The intervals are determined based on the topography of the flood plain. When a reliable source, such as the National Weather Service, predicts the expected flood stage for a specific event, the map can be used to determine what areas will be affected.

The maps depict the streets in the flood plain for easy interpretation when determining evacuation plans. The intervals on the map are generally adequate for interpretation.

Each map shows the community area in large scale and contains a set of instructions and graphics, as follows:

  1. Locate your property on the map.
  2. Determine the flood stage which will affect you. Consider not only water on your property, but also water preventing your evacuation.
  3. Listen for forecasts on the radio and television of stages at the stream gage used on the map.
  4. If the forecasted stage could affect you, begin emergency actions. If not, listen for revised forecasts until waters recede.
Flood Stages

EXAMPLE: If you live in House A, river stages greater than 24 feet [indicated as 24 on the map] would affect your property directly. If your evacuation route goes through a low-lying area, emergency action may be required at a lower stage than the stage affecting your property.

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Susquehanna River Basin Flood Facts

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Training Available

SRBC is offering training on local flood stage forecast maps to any local government, community, business, or citizen group interested. There is no registration fee for this training.

For further information, please contact SRBC at the following address:

Susquehanna River Basin Commission, 1721 N. Front St., Harrisburg, PA 17102

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Available Flood Stage Forecast Maps

Maps for areas marked with an * are available from the U.S. Army Corps of Engineers.


Municipality
County
Coverage
  Reach


Full or Partial

Pennsylvania


Allison Twp. Clinton
P
Jersey Shore-Lock Haven
Athens Boro. Bradford
F
Athens-Sayre-Susquehanna River and Chemung River
Athens Twp. Bradford
F
Athens-Sayre-Susquehanna River and Chemung River
Bald Eagle Twp. Clinton
P
Jersey Shore-Lock Haven
Bloomsburg Town Columbia
F
Town of Bloomsburg
Brady Twp. Lycoming
F
Turbot Twp. To Lycoming County
Buffalo Twp. Perry
P
Upper Paxton
Buffalo Twp. Union
P
Winfield to Lewisburg
Burnham Boro. Mifflin
F
Lewistown-Juniata/Kischocoquillas
Castania Twp. Clinton
P
Jersey Shore-Lock Haven
Chapman Twp. Clinton
*
*
Clinton Twp. Lycoming
P
Turbot Twp. To Lycoming County
Columbia Boro. Lancaster
F
Lower Susquehanna
Conyngham Twp. Luzerne
P
Shickshinny
Danville Boro. Montour
F
Danville
Delaware Twp. Northumberland
F
Turbot Twp. To Lycoming County
Derry Twp. Dauphin
F
Harrisburg-Swatara Cr. And Backwater
Derry Twp. Mifflin
F
Lewistown-Juniata/Kischocoquillas
Duboistown Boro. Lycoming
*
*
Duryea Boro. Luzerne
F
Wyoming Valley
East Buffalo Twp. Union
F
Winfield to Lewisburg
East Chillisquaque Twp. Northumberland
P
Winfield to Lewisburg
East Donegal Twp. Lancaster
P
Lower Susquehanna
East Hanover Twp. Dauphin
F
Harrisburg-Swatara Cr.
East Manchester Twp. York
P
York-Condorous Cr.
East Pennsboro Twp. Cumberland
F
Twp. Of East Pennsboro-River and Conodoquinet Cr.
Exeter Boro. Luzerne
F
Wyoming Valley
Fairfield Twp. Lycoming
*
*
Fairview Twp. York
F
Yellow Breeches
Flemington Boro. Clinton
F
Jersey Shore-Lock Haven
Forty Fort Boro. Luzerne
F
Wyoming Valley
Gamble Twp. Lycoming
*
*
Gregg Twp. Union
F
Turbot Twp. To Lycoming County
Harrisburg City Dauphin
*
*
Hellam Twp. York
P
Lower Susquehanna/Long Level Area-York County
Hepburn Twp. Lycoming
*
*
Hershey Village (Derry Twp.) Dauphin
F
Harrisburg-Swatara Cr.
Hughesville Boro. Lycoming
*
*
Hummelstown Boro. Dauphin
F
Harrisburg-Swatara Cr.
Jenkins Twp. Luzerne
F
Wyoming Valley
Jersey Shore Boro. Lycoming
*
*
Kelly Twp. Union
F
Winfield to Lewisburg/Turbot Twp. To Lycoming County
Kingston Boro. Luzerne
P
Wyoming Valley
Leidy Twp. Clinton
*
*
Lewis Twp. Lycoming
*
*
Lewisburg Boro. Union
F
Winfield to Lewisburg
Lewistown Boro. Mifflin
F
Lewistown-Juniata/Kischocoquillas
Lisburn Village (Lower Allen Twp.) Cumberland
F
Yellow Breeches
Liverpool Boro. Perry
F
Upper Paxton
Liverpool Twp. Perry
F
Upper Paxton
Lock Haven City Clinton
*
*
Londonderry Twp. Dauphin
F
Harrisburg-Swatara Cr. And Backwater
Long Level Area York
F
Long Level Area-York County
Lower Allen Twp. Cumberland
F
Yellow Breeches
Lower Augusta Twp. Northumberland
P
Sunbury to Selingsgrove
Lower Mahanoy Twp. Northumberland
P
Upper Paxton
Lower Swatara Twp. Dauphin
F
Harrisburg-Swatara Cr. And Backwater
Lower Windsor Twp. York
P
Long Level Area-York County
Loyalsock Twp. Lycoming
*
*
Lycoming Twp. Lycoming
*
*
Mahoning Twp. Montour
P
Danville
Manchester Twp. York
F
York-Condorous Cr.
Marietta Boro. Lancaster
F
Lower Susquehanna
Middletown Boro. Dauphin
F
Harrisburg-Swatara Cr. And Backwater
Mill Hall Boro. Clinton
F
Jersey Shore-Lock Haven
Millersburg Boro. Dauphin
F
Upper Paxton
Milton Boro. Lycoming
*
*
Milton Boro. Northumberland
*
*
Monoghan Twp. York
F
Yellow Breeches
Monroe Twp. Snyder
F
Sunbury to Selingsgrove
Montgomery Boro. Lycoming
*
*
Montoursville Boro. Lycoming
*
*
Muncy Boro. Lycoming
*
*
Muncy Creek Twp. Lycoming
*
*
New Cumberland Boro. Cumberland
F
Yellow Breeches
Newton Twp. Lackawanna
F
Wyoming Valley
North York Boro. York
F
York-Condorous Cr.
Noyes Twp. Clinton
*
*
Old Lycoming Twp. Lycoming
*
*
Penn Twp. Snyder
P
Sunbury to Selingsgrove
Piatt Twp. Lycoming
*
*
Pittston Boro. Luzerne
F
Wyoming Valley
Plains Twp. Luzerne
F
Wyoming Valley
Point Twp. Northumberland
P
Winfield to Lewisburg/Danville
Ransom Twp. Lackawanna
F
Wyoming Valley
Renovo Boro. Clinton
*
*
Riverside Boro. Northumberland
F
Danville
Royalton Boro. Dauphin
F
Harrisburg-Swatara Cr. And Backwater
Rush Twp. Northumberland
P
Danville
Sand Beach Village Dauphin
F
Harrisburg-Swatara Cr.
Sayre Boro. Bradford
F
Athens-Sayre-Susquehanna River and Chemung River
Selingsgrove Boro. Snyder
F
Sunbury to Selingsgrove
Shamokin Dam Boro. Snyder
F
Sunbury to Selingsgrove
Shickshinny Boro. Luzerne
F
Shickshinny
South Hanover Twp. Dauphin
F
Harrisburg-Swatara Cr.
South Renovo Boro. Clinton
*
*
South Waverly Boro. Bradford
F
Athens-Sayre-Susquehanna River and Chemung River
Spring Garden Twp. York
P
York-Condorous Cr.
Springettsbury Twp. York
F
York-Condorous Cr.
Sunbury City Northumberland
F
Sunbury to Selingsgrove
Swatara Twp. Dauphin
F
Harrisburg-Swatara Cr.
Swoyersville Boro. Luzerne
F
Wyoming Valley
Turbot Twp. Northumberland
F
Turbot Twp. To Lycoming County
Union Deposit Village Dauphin
F
Harrisburg-Swatara Cr.
Union Twp. Union
P
Winfield to Lewisburg
Upper Allen Twp. Cumberland
F
Yellow Breeches
Upper Augusta Twp. Northumberland
P
Sunbury to Selingsgrove
Upper Fairfield Twp. Lycoming
*
*
Upper Paxton Twp. Dauphin
F
Upper Paxton
Watsontown Boro. Northumberland
F
Turbot Twp. To Lycoming County
West Chillisquaque Twp. Northumberland
F
Winfield to Lewisburg/Turbot Twp. To Lycoming County
West Fairview Boro. Cumberland
F
Twp. Of East Pennsboro-River and Conodoquinet Cr.
West Hempfield Twp. Lancaster
F
Lower Susquehanna
West Manchester Twp. York
P
York-Condorous Cr.
West Pittston Boro. Luzerne
F
Wyoming Valley
West Wyoming Boro. Luzerne
F
Wyoming Valley
West York Boro. York
F
York-Condorous Cr.
White Deer Union
F
Turbot Twp. To Lycoming County
White Deer Twp. Union
F
Turbot Twp. To Lycoming County
Williamsport City Lycoming
*
*
Winfield Union
F
Winfield to Lewisburg
Wolf Twp. Lycoming
*
*
Wormleysburg Boro. Cumberland
P
Twp. Of East Pennsboro-River
Wrightsville Boro. York
F
Lower Susquehanna/Long Level Area-York County
Wyoming Boro. Luzerne
F
Wyoming Valley
York City York
F
York-Condorous Cr.




  Maryland


Havre de Grace City Harford
F
Conowingo Dam to Havre de Grace
Perryville Town Cecil
F
Conowingo Dam to Havre de Grace
Port Deposit District Cecil
F
Conowingo Dam to Havre de Grace
Port Deposit Town Cecil
F
Conowingo Dam to Havre de Grace
New York


Addison Town Steuben
P
Addison
Addison Village Steuben
F
Addison
Barker Town Broome
*
*
Bath Village Steuben
*
*
Big Flats Town Chemung
F
Big Flats
Big Flats Town Chemung
*
*
Binghamton City Broome
F
Binghamton-Susquehanna River and Chenago River
Campbell Town Steuben
*
*
Chemung Town Chemung
P
Athens-Sayre-Chemung River
Chenango Town Chenango
*
*
Cohocton Town Steuben
*
*
Conklin Town Broome
*
*
Dickinson Town Broome
F
Binghamton-Chenango River
Elmira City Chemung
F
Newtown Cr.
Elmira City Chemung
*
*
Elmira Heights Village Chemung
F
Newtown Cr.
Elmira Town Chemung
F
Newtown Cr.
Endicott Village Broome
F
Binghamton-Susquehanna River
Erwin Town Steuben
*
*
Fenton Town Broome
*
*
Greene Town Chenango
*
*
Horseheads Town Chemung
F
Newtown Cr.
Horseheads Village Chemung
F
Newtown Cr.
Johnson City Village Broome
F
Binghamton-Susquehanna River
Kirkwood Town Broome
*
*
Owego Village Tioga
F
Owego
Port Dickinson Village Broome
F
Binghamton-Chenango River
Southport Town Chemung
*
*
Union Town Broome
F
Binghamton-Susquehanna River
Vestal Town Broome
F
Binghamton-Susquehanna River
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