Report of the River Master of the Delaware River for the Period December 1, 2010–November 30, 2011

Open-File Report 2020-1020
By: , and 



A Decree of the Supreme Court of the United States, entered June 7, 1954, established the position of Delaware River Master within the U.S. Geological Survey. In addition, the Decree authorizes diversion of water from the Delaware River Basin and requires compensating releases from certain reservoirs, owned by New York City, to be made under the supervision and direction of the River Master. The Decree stipulates that the River Master will furnish reports to the Court, not less frequently than annually. This report is the 58th Annual Report of the River Master of the Delaware River. It covers the 2011 River Master report year, the period from December 1, 2010, to November 30, 2011.

During the report year, precipitation in the upper Delaware River Basin was 71.43 inches or 162 percent of the long-term average. On December 1, 2010, combined usable storage in the New York City reservoirs in the upper Delaware River Basin was 230.430 billion gallons or 85.1 percent of combined storage capacity. The reservoirs were at about 100 percent of usable capacity on May 31, 2011. Combined storage remained high (above 80 percent combined capacity) through November 2011. River Master operations during the year were conducted as stipulated by the Decree and the Flexible Flow Management Program.

Diversions from the Delaware River Basin by New York City and New Jersey were in full compliance with the Decree. Reservoir releases were made as directed by the River Master at rates designed to meet the flow objective for the Delaware River at Montague, New Jersey, on 5 days during the report year (July 24–28, 2011). Conservation releases, designed to relieve thermal stress and protect the fishery and aquatic habitat in the tailwaters of the reservoirs, were also made during the report year.

The quality of water in the Delaware Estuary between Trenton, New Jersey, and Reedy Island Jetty, Delaware, was monitored at various locations. Data on water temperature, specific conductance, dissolved oxygen, and pH were collected continuously by electronic instruments at four sites.

Suggested Citation

DiFrenna, V.J., Andrews, W.J., Russell, K.L., Norris, J.M., and Mason, R.R., Jr., 2020, Report of the River Master of the Delaware River for the period December 1, 2010–November 30, 2011: U.S. Geological Survey Open-File Report 2020–1020, 127 p.,

ISSN: 2331-1258 (online)

ISSN: 0196-1497 (print)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Definition of Terms and Procedures
  • Introduction
  • Method to Determine Directed Releases from New York City Reservoirs
  • Hydrologic Conditions
  • Operations
  • Comparison of River Master Operations Data with Other Records
  • Conformance of Operations Under the Amended Decree of the U.S. Supreme Court Entered June 7, 1954
  • Quality of Water in the Delaware Estuary
  • References Cited
  • Appendix 1. Agreement of the Parties to the 1954 U.S. Supreme Court Decree, Effective February 14, 2011
  • Appendix 2. Agreement for Revised FFMP Language to Address Water Equivalent of Snow Pack, Effective February 15, 2011
  • Appendix 3. Agreement of the Parties of the 1954 U.S. Supreme Court Decree for a Flexible Flow Management Program, Effective June 1, 2011
  • Appendix 4. Agreement for Temporary Thermal Releases Program for Fisheries Protection, Effective July 22, 2011
Publication type Report
Publication Subtype USGS Numbered Series
Title Report of the River Master of the Delaware River for the period December 1, 2010–November 30, 2011
Series title Open-File Report
Series number 2020-1020
DOI 10.3133/ofr20201020
Year Published 2020
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Office of the Associate Director for Water
Description x, 127 p.
Country United States
State New York, New Jersey, Pennsylvania
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details