Floods of 2011 in New York

Hurricane Irene

Figure 1 shows the declared counties for Hurricane Irene (FEMA)

Five to ten inches of rain from Hurricane Irene produced widespread moderate to major flooding throughout eastern New York August 28-30.  Highest rainfall totals occurred in the Catskill Mountains of southeastern New York where over 18-inches of rain was reported at Maplecrest, NY.  Record water-surface elevations and streamflows were recorded at 60 USGS streamgages and 2 lake/reservoirs.  Provisional recurrence intervals of peak flows exceeded the 100-yr flood (1 percent annual chance flood) at 25 USGS streamgages.  Provisional recurrence intervals of peak flows exceeded the 500-yr flood (0.2 percent annual chance flood) at 9 streamgages in the Schoharie Creek and Ausable River basins.

The President signed Major Disaster Declaration FEMA-DR-4020 on August 31, 2011 for the following counties in New York: 

Individual Assistance (Assistance to individuals and households):

Albany County, Bronx County, Clinton County, Columbia County, Delaware County, Dutchess County, Essex County, Greene County, Herkimer County, Kings County, Montgomery County, Nassau County, Orange County, Otsego County, Putnam County, Queens County, Rensselaer County, Richmond County, Rockland County, Saratoga County, Schenectady County, Schoharie County, Suffolk County, Sullivan County, Ulster County, Warren County, Washington County, and Westchester County. 

Public Assistance (Assistance to State and local governments and certain private nonprofit organizations for emergency work and the repair or replacement of disaster-damaged facilities):

Albany County, Bronx County, Clinton County, Columbia County, Delaware County, Dutchess County, Essex County, Franklin County, Greene County, Hamilton County, Herkimer County, Kings County, Montgomery County, Nassau County, New York County, Orange County, Otsego County, Putnam County, Queens County, Rensselaer County, Richmond County, Rockland County, Saratoga County, Schenectady County, Schoharie County, Suffolk County, Sullivan County, Ulster County, Warren County, Washington County, and Westchester County. 

http://www.fema.gov/pdf/news/pda/4020.pdf

The U.S. Geological Survey (USGS), in support of Federal Emergency Management Agency (FEMA) Region II, proposes a project to document the scope and magnitude of flooding in New York as a result of Hurricane Irene.  This study will document the effects of Irene in New York from New York City, the eastern end of Long Island, the Hudson Valley, and the Lake Champlain basin.  Throughout these regions, record stream- flows and damage occurred. This report will describe the meteorological and hydrological impacts in these areas. 

Some of the most severe damage occurred in Greene and Schoharie counties.  Along the length of the Schoharie Creek, flows were estimated to equal or exceed the 0.2 per cent annual chance flood.  The USGS collected high-water marks along the length of the Schoharie Creek under a separate IAA to provide many of the records detailed in this report.  Additional high-water marks were obtained by FEMA in the areas around eastern Long Island and in the Catskill Mountains within portions of Ulster and Delaware counties.  In addition, the New York State Canal Corporation obtained high-water marks at locks and dams along the Mohawk River where debris blockage at several locks and dams resulted in severe impacts to localized areas.  All these high-water marks are to be included in this report and tabulated by basin.  

Tropical Storm Lee 

Five to eleven inches of rain from the remnants of Tropical Storm Lee produced widespread moderate to major flooding throughout central New York September 7-10.  Highest rainfall totals were recorded in south-central New York adjacent to parts of Pennsylvania where totals neared 13 inches with most of it falling on September 8.  Record water-surface elevations and streamflows were recorded at about ten USGS streamgages in the Susquehanna River basin.  Provisional recurrence intervals of peak flows exceeded the 100-yr flood (1 percent annual chance flood) at 10 USGS streamgages.  Flooding significantly exceeded the previous flood of record (2006) along the Susquehanna River downstream from Conklin, NY, which resulted in several overtopped levees in the Broome County area and damage to hundreds of homes. 

The President signed Major Disaster Declaration FEMA-DR-4031 on September 13, 2011 for the following counties in New York: 

Individual Assistance (Assistance to individuals and households):

Broome County, Chemung County, Chenango County, Delaware County, Fulton County, Herkimer County, Oneida County, Orange County, Otsego County, Schenectady County, Schoharie County, Tioga County, and Ulster County.

 Public Assistance (Assistance to State and local governments and certain private nonprofit organizations for emergency work and the repair or replacement of disaster-damaged facilities):

Broome County, Chemung County, Chenango County, Delaware County, Herkimer County, Montgomery County, Oneida County, Orange County, Otsego County, Schenectady County, Schoharie County, Tioga County, Tompkins County, and Ulster County.

http://www.fema.gov/pdf/news/pda/4031.pdf

The U.S. Geological Survey (USGS), in support of Federal Emergency Management Agency (FEMA) Region II, also proposes to document the scope and magnitude of flooding in New York as a result of the remnants of Tropical Storm Lee in this study. 

Objectives

• Assess the meteorological conditions associated with the flooding from Hurricane Irene and the remnants of Tropical Storm Lee from National Weather Service (NWS) and other data. 
• Document the hydrologic conditions that caused major flooding resulting from Hurricane Irene and the remnants of Tropical Storm Lee. 
• Tabulate and plot gage-height and streamflow data collected during the floods at selected USGS streamgages. 
• Compare high-water mark elevations collected along Schoharie Creek during the USGS/FEMA IAA for the flood of August 28, 2011 to flood profiles in FEMA flood insurance studies and to high-water profiles collected by the USGS for the April 1987 and January 1996 floods. 
• Estimate the magnitude and recurrence interval of the flooding in the disaster declaration area by evaluating peak streamflow records at USGS streamgages in the study area. 
• Deliver the above information in a report for Federal and New York State agencies to use for recovery operations and hazard mitigation planning.

 Approach

The USGS will conduct, in support of the State of New York and FEMA Region II, a hydrologic study of streams in New York. This study will provide post-event flood risk management information and consist of the following tasks:

• Document meteorological conditions and flood impacts. USGS will assess the meteorological conditions associated with the flood using NWS data and other available rainfall data in the area. 
• Tabulate and plot gage-height and streamflow data collected during the flood at selected USGS streamgages in affected area. 
• Tabulate high-water marks collected and surveyed along Schoharie Creek during USGS/FEMA Interagency Agreement for: Schoharie Creek; Hunter, NY to Ft. Hunter, NY (80 river miles). 

The field form used by the New York Water Science Center to collect high-water marks will be included in the report as a reference to ensure consistent data collection by various agencies for future floods.  General procedures to locate, identify, and evaluate various types of high-water marks will also be discussed. 

 Event frequency determination. Flood frequencies will be determined by the USGS at gaged and ungaged locations. Flood frequencies at streamgages in the study area will be updated utilizing peak flows that occurred during the August 28-September 10, 2011 floods. The peak flows and their respective recurrence intervals will be compared with those presented in FEMA flood insurance studies. 

• Water-surface profiles. Using high-water elevation data, water-surface profiles along Schoharie Creek will be produced and compared to the 10-year, 50-year, 100-year, and 500-year flood profile elevations published in relevant FEMA flood insurance studies and to high-water profiles collected by the USGS for the April 1987 and January 1996 floods. 
• Report. Compile all data and summarize the results in a USGS Scientific Investigations Report (SIR).

 Publications

Lumia, Richard, Firda, G.D., and Smith, T.L., 2014, Floods of 2011 in New York: U.S. Geological Survey Scientific Investigations Report 2014–5058, 236 p., http://dx.doi.org/10.3133/sir20145058. http://pubs.usgs.gov/sir/2014/5058/

Project Location by County

NYWSCStatewide