Link to USGS home page.
Publications—Open-File Report

Prepared in cooperation with the Federal Emergency Management Agency

Flood of October 8 and 9, 2005, on Cold River in Walpole, Langdon, and Alstead and on Warren Brook in Alstead, New Hampshire

By Scott A. Olson

 

U.S. Geological Survey Open-File Report 2006-1221

 

The body of the report is available in PDF Format ( 36,677 KB)

Abstract

Southwestern New Hampshire experienced damaging flooding on October 8 and 9, 2005. The flooding was the result of a storm producing at least 7 inches of rain in a 30-hour period. The heavy, intense rainfall resulted in runoff and severe flooding, especially in regions of steep topography that are vulnerable to flash flooding. Some of the worst property damage was in the towns of Alstead, Langdon, and Walpole, New Hampshire along Cold River and Warren Brook. Warren Brook was severely flooded and had flows that exceeded a 100-year recurrence interval upstream of Cooper Hill Road. Downstream of Cooper Hill Road, the flooding was worsened as a result of a sudden release of impounded water, making the flood levels greater than what would be experienced from a 500-year recurrence-interval flood.

Along Cold River, upstream of its confluence with Warren Brook, flooding was at approximately a 100-year recurrence interval. Downstream of the confluence of Cold River and Warren Brook, the streamflows, which were swollen by the surge of water from Warren Brook, exceeded a 500year recurrence interval.

TABLE OF CONTENTS

Abstract

Introduction

Description of Investigated Reaches

Storm Characteristics

High-Water Marks

Peak-Discharge Estimates

Warren Brook at Mill Hollow

Warren Brook Downstream of Cooper Hill Road

Cold River at Vilas Pool Dam

Cold River Downstream of the Warren Brook Confluence

Cold River at the Drewsville USGS Stream-Gaging Station

Flood-Flow-Frequency Characteristics

Summary

Selected References

 

Appendixes 1–3.

  1. Maps Showing Location of High-Water Marks Flagged in Walpole, Langdon, and Alstead, NH, Following the Flood of October 8 and 9, 2005.
  2. Profiles of the October 2005 Flood on Cold River and Warren Brook, Southwestern New Hampshire.
  3. Elevation Benchmarks Along Cold River and Warren Brook, New Hampshire.

Figures

 

1–2. Maps showing—

  1. Location of investigated reaches and the towns of Walpole, Langdon, and Alstead, NH.
  2. Locations where peak discharge and flood-flow frequency were estimated in Walpole, Langdon, and Alstead, NH.
  3. Photograph showing view looking upstream at the Cooper Hill Road embankment failure October 2005 in Alstead, NH.

4–5. Graphs showing—

 

   4. Flood-flow frequency estimates for selected recurrence intervals at selected sites on Warren Brook, Alstead, NH.
   5. Flood-flow frequency estimates for selected recurrence intervals at selected sites on Cold River, Alstead, Langdon, and Walpole, NH.

 

Tables

  1. High-water elevations and locations of the October 2005 flood on Cold River in Walpole, Langdon, and Alstead, NH.
  2. High-water elevations of the October 2005 flood on Warren Brook in Alstead, NH.
  3. Basin characteristics and flood-flow frequency estimates for selected recurrence intervals at selected sites on Warren Brook, Alstead, NH.
  4. Flood-flow frequency estimates for selected recurrence intervals at selected sites on Cold River, southwestern New Hampshire, 2005.

If you have Adobe® Acrobat® or Adobe® Acrobat® Reader® installed on your computer, you may view and print the PDF version of this report. Acrobat Reader, is a free download from Adobe Systems, Inc. Users with disabilities can view information concerning accessibility at access.Adobe.com .

For further information, contact:

Keith W. Robinson, Director
U.S. Geological Survey
New Hampshire - Vermont Water Science Center
361 Commerce Way
Pembroke , NH 03275

dc_nh@usgs.gov

(603) 226-7807

or visit our Web site at: http://nh.water.usgs.gov

 


Accessibility FOIA Privacy Policies and Notices

Take Pride in America home page. FirstGov button U.S. Department of the Interior | U.S. Geological Survey
Persistent URL: http://pubs.water.usgs.gov/ofr20061221
Page Contact Information: USGS Publishing Network
Page Last Modified: Saturday, 12-Jan-2013 22:11:14 EST