Flood Inundation Map Available
--01570500 SUSQUEHANNA RIVER AT
--Lat 40`15'17", long
76`53'11", Dauphin County, Hydrologic Unit 02050305, on east
bank of City Island, 60 ft downstream from Market Street bridge in
Harrisburg, 3,670 ft upstream from sanitary dam, and 1.7 mi upstream
from Paxton Creek.
--24,100 square miles.
PERIOD OF RECORD.
--October 1890 to current year.
--Water-stage recorder. Concrete control since
Aug. 29, 1916. Datum of gage is 290.01 ft above National Geodetic
Vertical Datum of 1929. Prior to Oct. 1, 1928, non-recording gage at
Walnut Street Bridge 600 ft upstream, and Oct. 1, 1928, to Aug. 31,
1975, water-stage recorder at site 3,170 ft downstream, all gages at
--Station established and maintained by
the U.S. Geological Survey. Funding for the operation of this station
is provided by Exelon Generation, the Pennsylvania Department of
Environmental Protection and the U. S. Geological Survey through the
National Streamflow Information Program and the Cooperative Water
--Water temperature data collection at the
City Island site was discontinued on March 25, 2015.
WATER QUALITY DATA FROM THE WALNUT STREET
PIER LOCATION IS NOT TRANSMITTED VIA SATELLITE TELEMETRY AND THEREFORE
WILL ONLY BE UPDATED ABOUT EVERY 6 WEEKS.
Water-quality parameters at this station can vary
substantially at different locations in the river. Therefore,
water-quality data displayed here characterizes conditions only at the
location where water-quality equipment is deployed.
GAGE HEIGHTS OF IMPORTANCE
|The 30-minute precipitation data for this station are
temporary and will only be displayed for 120 days. Time series
of 1-hour or cumulative daily values will NOT be available for
retrieval following the 120-day display period. Although the
instrumentation is calibrated at least once a year, the temporary
classification means that documented routine inspections and other
quality assurance measures are not performed that would make the
data acceptable for archival, retrieval, or future use in general
scientific or interpretive studies.
Supplied by USGS
: Maximum recordable gage height
(stage sensor operational limit) - 45.2 ft; Data transmitter
operational limit - 46.2 ft;
Supplied by NWS
: Action stage 11 ft, recreational use
of City Island begins to be curtailed; river interests should monitor
conditions; Flood stage-17 ft, basements of residences and businesses
on both banks flood; the parking lot of City Island begins to take on
water; Moderate flood stage-20 ft, a number of homes in West Fairview,
Dauphin and Harrisburg flood; Major flood stage-23 ft, evacuations are
necessary in the Shipoke area of Harrisburg; the water level reaches
the corner of Keller and Front Streets.