thumbnail

Flood-inundation maps for the West Branch Delaware River, Delhi, New York, 2012

Scientific Investigations Map 3216

By:
,

Links

Abstract

Digital flood-inundation maps for a 5-mile reach of the West Branch Delaware River through the Village and part of the Town of Delhi, New York, were created by the U.S. Geological Survey (USGS) in cooperation with the Village of Delhi, the Delaware County Soil and Water Conservation District, and the Delaware County Planning Department. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/ and the Federal Flood Inundation Mapper Web site at http://wim.usgs.gov/FIMI/FloodInundationMapper.html, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) referenced to the USGS streamgage at West Branch Delaware River upstream from Delhi, N.Y. (station number 01421900). In this study, flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model that had been used to produce the flood insurance rate maps for the most recent flood insurance study for the Town and Village of Delhi. This hydraulic model was used to compute 10 water-surface profiles for flood stages at 1-foot (ft) intervals referenced to the streamgage datum and ranging from 7 ft or near bankfull to 16 ft, which exceeds the stages that correspond to both the estimated 0.2-percent annual-exceedance-probability flood (500-year recurrence interval flood) and the maximum recorded peak flow. The simulated water-surface profiles were then combined with a geographic information system (GIS) digital elevation model, which was derived from Light Detection and Ranging (LiDAR) data with a 1.2-ft (0.61-ft root mean squared error) vertical accuracy and 3.3-ft (1-meter) horizontal resolution, to delineate the area flooded at each water level. A map that was produced using this method to delineate the inundated area for the flood that occurred on August 28, 2011, agreed well with highwater marks that had been located in the field using a global positioning system. The availability of the 10 flood-inundation maps on the USGS Flood Inundation Mapping Science Web site, along with Internet information regarding current stage from the USGS streamgage, will provide emergency management personnel and residents with information that is critical for flood-response activities, such as evacuations and road closures, as well as for post-flood recovery efforts.

Geospatial Extents

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Flood-inundation maps for the West Branch Delaware River, Delhi, New York, 2012
Series title:
Scientific Investigations Map
Series number:
3216
Edition:
-
Year Published:
2012
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
New York Water Science Center
Description:
Pamphlet: vi, 9 p.; 10 Sheets; Sheet 1: 17 inches x 22 inches, Sheet 2: 17 inches x 22 inches, Sheet 3: 17 inches x 22 inches, Sheet 4: 17 inches x 22 inches, Sheet 5: 17 inches x 22 inches, Sheet 6: 17 inches x 22 inches, Sheet 7: 17 inches x 22 inches, Sheet 8: 17 inches x 22 inches, Sheet 9: 17 inches x 22 inches, Sheet 10: 17 inches x 22 inches; Downloads Directory
Country:
United States
State:
New York
County:
Delaware;Schoharie
City:
Delhi
Other Geospatial:
Catskill Mountain;Elk Creek;Falls Creek;Steele Brook
Datum:
North American Datum of 1983
Online Only (Y/N):
Y
Additional Online Files(Y/N):
Y