justifies accelerating the necessary research. Decision makers must decide 

 whether to base policies on today's inadequate knowledge or ignore the impli- 

 cations until they are more certain. 



One potential impact of a global warming and rise in sea- level would be 

 an increase in the salinity of estuaries, which might threaten drinking water 

 and aquatic ecosystems. The Delaware River Basin Commission (DRBC) has long 

 considered the implications of droughts on management of water resources in 

 the Delaware estuary; since 1979, it has also considered the implications of 

 recent sea-level trends. However, the DRBC has not previously focused on the 

 possibility that the "greenhouse warming" could exacerbate salinity problems. 

 The Environmental Protection Agency has initiated studies on the impacts of 

 sea-level rise and climate change on erosion, flooding, and wetland protec- 

 tion, but has not previously examined the impacts on salinity. 



This joint report by the Environmental Protection Agency and the 

 Delaware River Basin Commission examines the implications of the greenhouse 

 warming for salinity control in the Delaware estuary. The study focuses on 

 the implications of (1) a 21-inch rise in global sea-level expected by 2050, 

 which would imply arise of 2.4 ft in the Delaware estuary; and (2) a 7-ft 

 global rise by 2100, which would imply an 8.2-ft rise in the Delaware estuary. 

 The authors estimate the increase in estuary salinity, estimate the possible 

 increase in salinity of the Potomac -Raritan-Magothy aquifer system, discuss 

 the implications, and examine possible responses. Potential changes in 

 precipitation are not evaluated. (Summary). 



156 HULL, C. H. J., and TORTORIELLO, R. C. 1979. "Sea-Level Trend and 

 Salinity in the Delaware Estuary," Staff paper, Delaware River Basin 

 Commission, West, Trenton, NJ , pp 19. 



In 1954, the United States Supreme Court authorized the City of New York 

 and the State of New Jersey to divert water from the Delaware River Basin. 

 New York City was permitted to take water at a yearly average rate not to 

 exceed 800 mgd provided certain compensatory releases from storage reservoirs 

 were made to the Delaware River for protection of downstream water quality. 

 The State of New Jersey was authorized to divert the equivalent of 100 mgd as 

 a monthly average, with the diversion on any day not to exceed 120 million 

 gallons . 



During the drought of the 1960s, it became clear that the runoff from 

 the drainage area above New York City's Delaware Basin impoundments was not 

 great enough to provide both the authorized diversion and the decreed down- 

 stream releases. At that time, the Comprehensive Plan for water resources 

 development in the Delaware River Basin included a series of authorized 

 storage reservoirs that would have offset the water deficit projected for a 

 future drought equal in severity to that of the sixties. However, in the 

 seventies, some of the authorized projects became controversial, and currently 

 at least two of these, including the largest in the Comprehensive Plan, are 

 not considered viable for a planning horizon of 20 years ahead (year 2000) . 

 Because of the projected water deficit for a recurrence of a severe drought, 

 the parties to the 1954 Supreme Court decree agreed in early 1979 to negotiate 

 in good faith to determine how best to allocate the increasingly scarce water 

 resources of the Delaware Basin. 



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