Delaware • New Jersey • Pennsylvania
New York • United States of America
For Immediate Release
February 2, 1999
(WEST TRENTON, N.J) - A drought warning, which resulted in tightened water supplies for New York City and portions of New Jersey, ended today, the result of recent drenching rains and melting snowpack.
The late January storms helped replenish reservoir storage in the Delaware River Basin and flush salt-laced water in the Delaware River downstream towards the ocean.
Over six inches of precipitation were recorded in some areas of the watershed last month, almost doubling normal levels for January, and storage in headwater reservoirs was further bolstered by runoff from thawing snow and ice.
The drought warning was issued by the Delaware River Basin Commission (DRBC) on December 14, 1998, following five months of extremely dry weather. It applied to those portions of New York State, Pennsylvania, New Jersey, and Delaware that make up the 13,539 square-mile drainage area of the Delaware River and its tributary waterways.
Exempted were Cumberland and Cape May counties in New Jersey, and the area below the Chesapeake and Delaware Canal in Delaware because water usage in these portions of the basin has little or no impact on salt water intrusion.
Under the Commission's drought management plan, a warning ends when combined storage in three huge water supply reservoirs in the upper basin increases to at least 15 billion gallons above a designated drought warning zone and stays above that level for five consecutive days. Storage topped the 15-billion gallon buffer last Thursday and remained above it through today.
The three impoundments, Pepacton, Neversink and Cannonsville, are owned by New York City, which lies outside the basin, but gets roughly half its water from the reservoirs through gravity-fed aqueducts. The impoundments are located at the Delaware River's headwaters in the Catskill Mountains and account for roughly 75 percent of the total surface water storage in the basin.
The reservoirs hold 271 billion gallons of useable water when full. As of today, combined storage was 165 billion gallons or 61 percent of capacity. Normally on this date the reservoirs are 79 percent full holding 215 billion gallons.
In a healthy hydrologic cycle, storage in the reservoirs would be increasing during the late fall and winter months when water demand drops off and thirsty vegetation has died off or is dormant. Last year, however, storage fell by 78 billion gallons from October 1 through December and continued the decline into early January.
By late November, reservoir levels were 25 percent below normal, prompting the DRBC to preempt its formal drought operating plan in an effort to get a head start on the worsening drought conditions.
Under an agreement among the Commission and the parties to a 1954 U.S. Supreme Court decree that apportioned the waters of the Delaware, a decision was made to throttle back both releases from the reservoirs into the Delaware and reservoir withdrawals by New York City.
During normal hydrologic conditions, New York can take up to 800 million gallons a day (mgd) from the impoundments. In return, it must release sufficient water into the Delaware to meet a downstream flow target of 1,750 cubic feet per second (cfs) at Montague, N.J., located just downstream of Port Jervis, N.Y. In addition, the DRBC directs releases from two lower basin reservoirs to maintain a flow target of 3,000 cfs at Trenton.
Under the agreement reached on November 21, the flow targets were reduced to 1,655 cfs at Montague and 2,700 cfs at Trenton and New York City's take from its reservoirs was cut to 680 mgd.
When the basin entered the first stage of drought warning on December 14, a water diversion to northern New Jersey through the Delaware and Raritan Canal was reduced from 100 mgd to 85 mgd. The water supply channel feeds off the Delaware River upstream of Trenton and winds its way to the Raritan River at New Brunswick.
A second stage drought warning kicked in on December 23 and the diversions were further reduced: New York City dropped from 680 mgd to 560 mgd; New Jersey from 85 mgd to 70 mgd. The Montague streamflow target was lowered from 1,655 cfs to 1,550 cfs.
In all, 12.8 billion gallons of water were saved in reservoir storage as the result of these drought management actions.
With the drought warning now lifted, the diversions and streamflow targets revert back to normal levels.
The lack of rain that began in mid-July not only impacted reservoir storage and streamflows, but caused significant decreases in ground water levels throughout the basin. Flows rebounded as a result of the late January storms and ground water levels are recovering, but are still well below normal for this time of year.
The Commission's drought plan focuses on salinity intrusion -- the upstream migration of salty water from the Delaware Bay during low-flow conditions in basin rivers and streams.
As part of a pact generated by the Commission among the basin states and New York City (the parties to the 1954 U.S. Supreme Court decree), the city must release sufficient water into the Delaware River from its three reservoirs to help repel, or flush back, the salt-laced water, known in water jargon as the "salt front" (a seven-day average 250 milligrams per liter chloride concentration.)
Runoff from January's storms swelled the Delaware and tributary streams, the rush of sea-bound fresh water pushing the salt front downstream to River Mile 69 at the Delaware Memorial Bridge. That's one mile above its average location for this time of year. During the height of the drought, the salty water had migrated as far north as River Mile 85, about four miles downstream of the Philadelphia's International Airport.
As the salt-laced water moves upriver it increases corrosion control costs for surface water users, particularly industry, and can raise the treatment costs for public water purveyors.
In recent dry years, salty water also has migrated into streams and creeks in Delaware, threatening water supplies in northern New Castle County.
In addition to releases from the three New York City reservoirs, 4.89 billion gallons of water were released during the dry spell from Beltzville Reservoir on the Lehigh River and Blue Marsh Reservoir on the Schuylkill River to improve flows, enhance water quality, and protect fisheries. The releases also helped to repel salinity.
And, when the drought warning was in effect, a consortium of electric utilities in the basin released water from Merrill Creek Reservoir to make up for evaporative losses at their riverbank generating stations during low flow periods on the Delaware. The 16-billion gallon impoundment, located near Phillipsburg, N.J., came on line in 1982. In all, 666 million gallons of water were released into the river from Merrill Creek.
The basin has entered into drought warning ten times since the early 1980s when the Commission's drought management plan was adopted. Two times, in 1981 and 1985, conditions worsened and drought emergencies were declared. The last drought warning occurred in the fall of 1998 and lasted less than two months.
The Delaware Basin stretches some 330 miles from the Delaware River's headwaters in New York State to the mouth of the Delaware Bay.
The DRBC, which is responsible for managing the water resources in the basin, was formed in 1961. The DRBC commissioners are the governors of the four basin states and a federal representative appointed by the President.
The following counties in Pennsylvania fall entirely within the Delaware River Basin: Bucks, Delaware, Lehigh, Monroe, Montgomery, Northampton, Philadelphia, and Pike.
Pennsylvania counties that fall partially within the basin: Berks (99%), Carbon (99%), Chester (80%), Lackawanna (9%), Lancaster (1%), Lebanon (5%), Luzerne (10%), Schuylkill (43%), and Wayne (96%).
The following New Jersey counties fall entirely within the basin: Cumberland, Salem and Warren.
Those partially in the basin: Atlantic (4%), Burlington (55%), Camden (50%), Cape May (33%), Gloucester (83%), Hunterdon (35%), Mercer (70%), Monmouth (25%), Morris (13%), Ocean (20%), and Sussex (67%).
There are no counties in New York State or Delaware that are completely in the basin.
New York counties partially in the basin: Broome (2%), Chenango (1%), Delaware (85%), Greene (2%), Orange (15%), Schoharie (1%), Sullivan (95%), and Ulster (15%).
Delaware counties partially in the basin: Kent (65%), New Castle (90%), and Sussex (20%).
Editors and News Directors: A list of the communities (townships, towns, etc.) located within the Delaware River Basin can be found on the DRBC's web site.