Skip Links

USGS - science for a changing world

Scientific Investigations Report 2013–5187

Prepared in cooperation with the U.S. Department of Homeland Security Federal Emergency Management Agency

Annual Exceedance Probabilities of the Peak Discharges of 2011 at Streamgages in Vermont and Selected Streamgages in New Hampshire, Western Massachusetts, and Northeastern New York

By Scott A. Olson and Gardner C. Bent

Thumbnail of and link to report PDF (12.6 MB)Abstract

The U.S. Geological Survey, in cooperation with the Federal Emergency Management Agency, determined annual exceedance probabilities for peak discharges occurring during the 2011 water year (October 1 to September 30) at streamgages in Vermont and selected streamgages in New Hampshire, western Massachusetts, and northeastern New York. This report presents the 2011 water year peak discharges at 145 streamgages in the study area and provides the results of the analyses of the 50-, 20-, 10-, 4-, 2-, 1-, and 0.2-percent annual exceedance probability discharges at 135 of the 145 streamgages. The annual exceedance probabilities for the 2011 water year peak discharges also are presented.

Snowmelt and near record rainfall led to flooding across northern Vermont on April 27 and 28, 2011. At three streamgages with more than 10 years of record, the April rain event resulted in the peak discharge of record. At seven streamgages, the peak discharge resulting from this event had an annual exceedance probability less than or equal to 1 percent. In early May 2011, new peak stage records were set at two Lake Champlain gages with more than 100 years of record. At the Lake Champlain at Burlington, Vermont, gage, the water surface reached 102.79 feet (ft) (North American Vertical Datum of 1988 (NAVD 88)) on May 6, 2011, and at the Richelieu River (Lake Champlain) at Rouses Point, New York, gage, the water surface reached 102.75 ft NAVD 88.

Record-breaking rainfall in late May produced additional flooding across northern Vermont on May 26 and 27, 2011. Four streamgages in northwestern Vermont recorded peak-of-record discharges as a result of this flooding. At three streamgages, the peak discharges from this event had an annual exceedance probability less than or equal to 1 percent.

From August 28 to 29, 2011, Tropical Storm Irene delivered rainfall totals ranging from about 3 to more than 10 inches, which resulted in extensive flooding and new period-of-record peak discharges at 37 streamgages in the study area. The peak discharges as a result of Tropical Storm Irene had an annual exceedance probability of less than or equal to 1 percent at 36 streamgages. At 11 of these 36 streamgages, the annual exceedance probability of the peak discharges was less than or equal to 0.2 percent.

First posted December 3, 2013

For additional information, contact:
Office Chief, New England Water Science Center
U.S. Geological Survey
New Hampshire-Vermont Office
331 Commerce Way, Suite 2
Pembroke, NH 03275
(603)226-7800
http://nh.water.usgs.gov

Part or all of this report is presented in Portable Document Format (PDF). For best results viewing and printing PDF documents, it is recommended that you download the documents to your computer and open them with Adobe Reader. PDF documents opened from your browser may not display or print as intended. Download the latest version of Adobe Reader, free of charge.


Suggested citation:

Olson, S.A., and Bent, G.C., 2013, Annual exceedance probabilities of the peak discharges of 2011 at streamgages in Vermont and selected streamgages in New Hampshire, western Massachusetts, and northeastern New York: U.S. Geological Survey Scientific Investigations Report 2013–5187, 17 p., http://dx.doi.org/10.3133/sir20135187.

ISSN 2328-0328 (online)



Contents

Abstract

Introduction

Peak Discharge and Lake Elevation Data for Water Year 2011

Frequency Analyses

Lake Champlain Peak Elevations and Frequency Analyses

Summary

Selected References

Appendix 1. Location Descriptions of Streamgages and Lake Gages Used to Characterize 2011 Flooding in Vermont, Northern New Hampshire, Western Massachusetts, and Northeastern New York

Appendix 2. Peak Discharge or Stage Occurring in 2011 at Streamgages or Lake Gages Used to Characterize 2011 Flooding in Vermont, Northern New Hampshire, Western Massachusetts, and Northeastern New York

Appendix 3. Discharges for Selected Annual Exceedance Probabilities at Streamgages Used to Characterize Flooding in 2011 in Vermont, Northern New Hampshire, Western Massachusetts, and Northeastern New York


Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: https://pubs.usgs.gov/sir/2013/5187/
Page Contact Information: Contact USGS
Page Last Modified: Tuesday, December 03, 2013, 02:24:59 PM