|
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.
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.
What
are the benefits of FLOOD STAGE FORECAST MAPS?
The
proper use of a flood stage forecast map can help:
- Save
Lives
- Reduce
Property Damage
- Facilitate
in Developing Evacuation Plans
- Provide
Local Interpretation of National Weather Service Flood Warnings
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.
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.
Susquehanna
River Basin Flood Facts:
- The
Susquehanna River Basin comprises less than 1% of the land area of the
continental United States, but experiences 6% of the national average
flood damages.
- Damages
from flood-related events total an average of $113 million per year
in 1993 dollars.
- About
30% of the basin's population (1.12 million people) live along major
rivers.
- About
1,160 of the 1,400 communities in the basin are in flood-prone areas.
- Pennsylvania,
which comprises 74% of the basin, has more streams and tributaries than
any other state in the continental United States.
- Local
flooding occurs every year and major devastating floods along
the main river hhappen on an average of once every 20 years.
- 1972
- the year of Hurricane Agnes - is the wettest year on record for the
basin. 1996 is the second wettest year on record for the basin, when
rain and snowfall caused several flooding events throughout the year.
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
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
|
| Cunningham 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
|
Return to Brochures
Main Page
|
