Dates of DRBC-Declared Drought

July 1965 - March 1967
October 1980 - April 1999
May 1999 - November 2002
September 2010 - October 2010
November 2016 - January 2017

DRBC drought operating plans are implemented either basinwide or for the lower basin. The plans complement the drought operating plans of the states, which are developed to respond to local water supply conditions.

DRBC’s Basinwide Drought Operations are based on storage conditions in three New York City (NYC) reservoirs, located at the headwaters of the Delaware River. These reservoirs include Cannonsville Reservoir on the West Branch of the Delaware River, Pepacton Reservoir on the East Branch of the Delaware River, and Neversink Reservoir on the Neversink River. During drought conditions, when the combined storage of the NYC reservoirs is below normal operations levels, the operating plans require phased reductions in:

  • Flow objectives for the Delaware River at Montague, NJ and Trenton, NJ;
  • Out-of-basin diversions from the NYC reservoirs and for New Jersey;
  • Conservation release rates from the NYC reservoirs, Beltzville, Blue Marsh, FE Walter, and Lake Nockamixon; and
  • Replacement of consumptive use (evaporative losses) from thermoelectric utilities.

The purpose of the reductions and of the consumptive use replacement is to conserve water in the basin’s reservoirs and to preserve water quality in the Delaware River by controlling the upstream movement of salty water from the Delaware River Estuary.

DRBC’s Basinwide Drought Operations were not always triggered by combined storage in the NYC Delaware Reservoirs. When the DRBC was created in October 1961, Section 10.4 of the Delaware River Basin Compact (pdf 341 KB) granted the commission the authority to declare a water supply emergency based on, "a drought or other condition which may cause an actual and immediate shortage of available water". DRBC exercised this authority when it declared an emergency during the Drought of Record in the 1960s. It was not until the following decade that the DRBC began to define drought operations using rule curves that represented combined storage in Neversink, Pepacton and Cannonsville reservoirs.

DRBC's Lower Basin Drought Operations are triggered by elevations in Blue Marsh and Beltzville reservoirs in the portion of the basin downstream of Montague, NJ. When both reservoirs fall below their respective drought warning and drought levels, the Trenton flow objective and diversions to the Delaware and Raritan Canal are reduced. Typically, basinwide drought operations prevail over Lower Basin drought operations.

Lower basin drought operations were approved a few years after the basinwide drought criteria were developed. Recommendation 4 of the Good Faith Agreements (pdf 7.46 MB) declared criteria for defining lower basin drought warning and drought be prepared. In June 1983, the commission directed its Flow Management Technical Advisory Committee to develop alternative operating plans using criteria from Recommendation 4. The operating plans were approved by resolution in September 1988. To date, the only lower basin drought declared by DRBC occurred in 2010.

July 1965 - March 1967

The northeastern section of the country experienced the “drought of record” beginning in 1962. Precipitation deficits increased with each passing year. By July 1965, the U.S. Weather Bureau’s Palmer Index indicated that extreme drought conditions existed over 100,000 square miles, extending from the Mid-Atlantic states to New England.

DRBC declared its first-ever drought emergency in July 1965. That month, the commission adopted a resolution to declare a water supply emergency and another to modify the 1954 Supreme Court Decree, with unanimous consent of the Decree Parties, to reduce NYC’s out of basin diversion, reduce the flow target at Montague, N.J., and limit releases from the NYC reservoirs to conserve storage.

DRBC also issued conversation orders to other reservoir systems in the basin to store water in order to be released to augment freshwater flows into the river and estuary to help limit the advance of the salt front.

Later in 1965, flow objectives at Montague and Trenton, N.J. were lowered to further decrease demand on reservoir storage.

Drought continued in the Delaware River Basin into 1966. Due to the uncertain hydrologic conditions, DRBC extended the drought emergency several times during the year. Precipitation amounts, streamflow and groundwater levels all began to improve by the fall of 1966. Storage in the NYC reservoirs increased to normal after a wet fall and winter of 1966-67. Groundwater was also recharged. Confident that the six-year drought had come to an end, DRBC adopted a resolution in March 1967, terminating its 20-month long water supply emergency.

October 1980 - April 1999

Dates of "Drought Actions" in the Delaware River Basin as determined by the DRBC Drought Management Plan: 

10/17/80 1/15/81 1/16/81 4/27/82
11/13/82 3/27/83    
11/09/83 12/20/83    
1/23/85 5/12/85 5/13/85 12/18/85
1/16/89 5/12/89    
9/13/91 6/17/92    
9/21/93 12/6/93    
9/15/95 11/12/95    
10/27/97 1/13/98    
12/14/98 2/2/99    
1. See Figure 1 below for a graphic of these Operation Curves.

2. The "ENTER DW" column represents the date the basin entered the first stage of Drought Warning (DW1).

3. The "ENTER DRT" column represents the date the basin entered Drought.

4. On 11/21/98, special action was taken before the combined storage in the three New York City (NYC) Delaware reservoirs (Cannonsville, Pepacton, and Neversink) officially entered Drought Warning to (a) reduce flow targets at Montague, N.J. and Trenton, N.J. and (b) to reduce the NYC diversions. DW1 wasn't officially entered until 12/14/98 and DW2 was entered on 12/23/98. The DRBC declared a conditional Drought Emergency on 1/5/99, which would have kicked in had the storage in the NYC reservoirs dropped into the Drought zone and remained there for five consecutive days. Heavy and persistent rain storms soaked the basin a week later, so the emergency was not triggered.

Figure 1.

Figure 1: Drought operation curves with Drought Warning 1 and Drought Warning 2 stages.
When full, the three reservoirs hold 271 billion gallons of combined storage.

May 1999 - November 2002

In May 1999, the operation curves for Cannonsville, Pepacton, and Neversink reservoirs were revised. Drought Watch replaced the Drought Warning Stage 1 (DW1) and the Drought Warning threshold (formerly DW2) was raised by 4 billion gallons based on the New York State Experimental Fisheries Program, D-77-20 (Rev. 4). See Figure 2 below for a graphic of the revised curves.

10/29/01 11/3/01 11/4/01 11/30/01 12/1/01 12/17/01 12/18/01 11/25/02

1. On 7/21/99, the flow target at Trenton was temporarily reduced in an effort to conserve dwindling water supplies. On 8/18/99, the DRBC ratified this decision and adopted emergency drought actions to address the severity of the water shortage even though the commission's drought operating plans had not yet been triggered by NYC reservoir storage levels. The emergency drought actions were lifted on 9/30/99.

2. View the "Chronology of Drought in the Delaware River Basin" (pdf 118 KB) for additional details about the 2001-2002 drought.
Figure 2.
Figure 2: Revised drought operation curves for Cannonsville, Pepacton, and Neversink reservoirs.
September 2010 - October 2010

On September 24, 2010, DRBC issued a lower basin drought warning. Persistently dry weather conditions over the summer necessitated directed releases from the Beltzville and Blue Marsh reservoirs in order to meet the flow objective at Trenton, N.J. The amount of water in those reservoirs was thereby reduced to levels that automatically triggered the lower basin drought warning declaration. Heavy rainfall during the last week of September increased storage in both reservoirs to above the drought warning elevations. The drought warning was lifted on October 31, 2010 after elevations in both reservoirs had been above the trigger per the lower basin drought operating plan. 

9/24/10 10/31/10    
November 2016 - January 2017

Drought returned to the Basin late in 2016. In response to declining reservoir storage and increasing precipitation deficits, DRBC held a drought hearing on November 9, 2016 (pdf 1.9 MB) to accept public input about the drought issues impacting the basin. On November 23, as combined storage in the NYC Delaware reservoirs declined to the drought watch range, DRBC held a special meeting and unanimously approved Resolution 2016-07 (pdf 698 KB) for coordinated operation of regional reservoirs, out-of-basin diversions, and Delaware River flow objectives in response to the persistent dry conditions. The resolution deemed the entire basin under a drought watch.

The drought was short-lived, but before it ended the salt front had reached as far upstream as Delaware river mile 90 in late November.

At the December 14, 2016 DRBC business meeting, Resolution 2016-8 (pdf 96 KB) was approved, which temporarily placed water stored in Lake Wallenpaupack and the Mongaup Reservoir System under operations designed to preserve and protect water supplies in the basin during a period of persistent dry conditions.

The month of December brought increased precipitation, improving streamflow, groundwater levels, and reservoir storage throughout the basin. The commission lifted the basinwide drought watch on January 18, 2017.