Hurricane Sandy was a major storm event for the tidal areas of Delaware. As a part of the mission of the Delaware Geological Survey, we have compiled preliminary Delaware tide and stream-level data for Hurricane Sandy and compared them with previous flooding records. The following tables are the result of the compilation. Please note that these data are preliminary and are subject to change as the data are verified. We have also included some rainfall data to show the rainfall distribution throughout the state related to the storm. These data were provided by the Delaware State Climatologists Office (http://climate.udel.edu/) and were collected as part of the Delaware Environmental Operating System (DEOS, http://www.deos.udel.edu/). The following map shows the location of the stream and tide gages and the DEOS stations used in this report.
Rainfall data provided by DEOS.
The following table is a summary of the preliminary tidal high water levels produced by Hurricane Sandy. The record high levels prior to Hurricane Sandy, the date of these levels, and the event (storm or hurricane) are shown for comparison. Nine record levels were reached for the tide gages on the Nanticoke River, in the Inland Bays and along the tidal portion of the Delaware River and its tributaries north of the Chesapeake and Delaware Canal. We have also included two NOAA tide gage graphs (at the bottom of this page) from Breakwater Harbor and Reedy Point that show the rise and fall of the tides during the storm. The difference between the predicted tides and the actual tides is the tidal surge that was the result of the storm.
|Hurricane Sandy||Prior Record High|
|Station||Gage Height (ft)||Date||Timez||Gage Height (ft)||Date||Event||Tidal
|Delaware River at Marcus Hook||9.94||10/30/12||3:30||9.76||4/17/11||low pressure system||MLLW||NOAA|
|Christina River at Newport||***8.06||10/30/12||2:18||8.07||9/17/99||Floyd||NGVD 1929||USGS|
|Christina River at Wilmington||8.26||10/30/12||2:36||7.71||4/16/11||low pressure system||NGVD 1929||USGS|
|Delaware River at New Castle||failed during storm||*7.68||5/12/08||Mothers Day Storm||NAVD 1988||USGS|
|Delaware River- Delaware City||9.74||10/30/12||1:54||9.38||4/16/11||low pressure system||MLLW||NOAA|
|Reedy Pt.- Mouth of C&D Canal||9.10||10/30/12||1:42||9.23||4/16/11||low pressure system||MLLW||NOAA|
|Murderkill River at Frederica||4.84||10/29/12||13:18||5.15||5/12/08||Mothers Day Storm||NGVD 1929||USGS|
|Murderkill River at Bowers||4.79||10/29/12||10:36||8.23y||3/3/94||Northeaster||NAVD 1988||USGS|
|Ship John Shoal||9.42||10/30/12||0:12||9.29||4/16/11||low pressure system||MLLW||NOAA|
|Brandywine Shoal Light||failed during storm||8.66||8/27/11||Irene||MLLW||NOAA|
|Breakwater Harbor at Lewes||8.70||10/29/12||9:36||9.22||3/6/62||March '62 Storm||MLLW||NOAA|
|Indian River Inlet||**6.51||10/29/12||9:54||**5.86||2/5/98||Northeaster||NGVD 1929||USGS|
|Indian River at Rosedale||6.23||10/29/12||10:48||6.99||2/5/98||Northeaster||NGVD 1929||USGS|
|Rehoboth Bay at Dewey Beach||5.34||10/29/12||22:30||4.45||10/31/99||Halloween Northeaster||NGVD 1929||USGS|
|Jefferson Creek at South Bethany||5.44||10/30/12||0:42||3.52||9/19/03||Isabel||NGVD 1929||USGS|
|Little Assawoman Bay||4.82||10/30/12||0:00||3.13||10/25/05||Wilma||NGVD 1929||USGS|
|Nanticoke River at Sharptown||5.59||10/30/12||4:36||4.11||3/3/94||Northeaster||NGVD 1929||USGS|
|*||gage malfunction, reading may be spurious|
|**||data erratic, high winds and waves|
|***||no data collected between 2:18 and 4:18 EDT during peak tide|
|y||previous tide gage, record for the present gage is 7.8 ft for the Mothers Day storm 5/12/08|
|9.94||red and bold indicates new record high|
|z||Eastern Daylight Time|
Although significant rainfall occurred throughout Delaware and in southeastern Pennsylvania, no new record stream levels were recorded. Flood stage was reached on five of the streams in northern Delaware. The levels shown in the following table are typical for a heavy rainfall event. We have also included three USGS hydrographs (at the bottom of this page) from the Brandywine at Wilmington, Red Clay Creek near Stanton, and White Clay Creek near Newark streamgages that show the rising water levels in the streams during the storm. It is possible or even likely that in areas in the Coastal Plain of Delaware where rainfall was the heaviest that small streams and ditches may have had significant flooding but no stream gages are located in these areas to record the event.
|USGS Station||Hurricane Sandy
Gage Height (ft)
|Flood Stage (ft)||Record
Gage Height (ft)
|Brandywine Crk at Wilm||16.66||16.50||*18.71||Hurricane Irene 2011|
|Shellpot Creek||5.78||8.00||13.76||Thunderstorm 1989|
|Red Clay Creek at Woodale||>7.45**||7.50||17.62||TS Henri 2003|
|Red Clay Creek near Stanton||17.00||16.00||25.52||TS Henri 2003|
|White Clay Creek at Newark||9.84||11.50||17.13||Hurricane Floyd 1999|
|White Clay Creek near Newark||15.12||13.50||*17.57||Hurricane Floyd 1999|
|Christina River at Cooch's Bridge||12.35||10.50||13.73||Hurricane Floyd 1999|
|St. Jones River at Dover||7.70||-||11.72||Hurricane Irene 2011|
|Nanticoke River at Bridgeville||8.25||-||10.31||1979|
|*||Record gage height at curent gage location|
|**||Highest recorded value before going out of service during the storm|
About the gages, stream and tide data
The Delaware Geological Survey (DGS) is actively involved in the monitoring of natural hazards such as stream and tidal flooding that are the result of large storms. The DGS identifies and investigates natural hazards to help understand the earth systems that present the hazards and determine strategies to prepare for or mitigate the risks. We are active in advising both county and state emergency management agencies on natural hazards. The DGS serves on the Delaware Emergency Management Agency’s (DEMA) Emergency Response Task Force for flooding, northeasters, and hurricanes and had staff located at the Delaware Emergency Operations Center during Hurricane Sandy.
An important component of monitoring storm events is having a real-time stream and tide gage network. These gages allow for monitoring of flooding during a storm as it happens to provide information to emergency managers and responders regarding areas of flooding and areas that may be flooded given the trends of rising stream or tide levels. The US Geological Survey, in cooperation with the Delaware Geological Survey, through a Federal-State partnership program operates and maintains stream and tide gages throughout Delaware.
Funding for operation and maintenance of this partnership program is provided by the Delaware Geological Survey, US Geological Survey, Delaware Department of Natural Resources and Environmental Control, Delaware Emergency Management Agency, City of Wilmington, City of Newark, and United Water Delaware.
The National Oceanic and Atmospheric Administration (NOAA) maintains tide gages in the Delaware Bay and River for purposes of navigation safety, environmental stewardship, and environmental assessment and prediction. These gages are an invaluable resource for real-time tidal conditions in the Delaware Bay and River.