Water Supply
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Inhabitants
of the Delaware River Basin get their water from surface and ground
sources, depending on where they live within the watershed. |
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Urban
areas make use of the rivers near which they were founded, while suburban
and rural regions rely more on groundwater from regional wells. |
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Eighty
percent of the water systems in the U.S. tap a ground water source for
their water supply, with 10-20% of people using their own private wells
for drinking water. |
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However,
the majority of the American population (66%) is served by a surface water
system (EPA, http://www.epa.gov/safewater/faq/faq.html#source).
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In the
Delaware River Basin, 88% percent of the total amount of water withdrawals
is taken from surface water supplies, whereas 12% comes from groundwater
sources (based on 1991 and 1993 data, DRBC, http://www.state.nj.us/drbc/gwsw93.htm).
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Surface
sources supply 60% of the water that is used consumptively, with
the remaining 40% coming from groundwater stores (USGS NAWQA, 1999). |
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Consumptive
water use, as defined by the DRBC is: "that part of water withdrawn
which is evaporated, transpired, incorporated into products or crops,
consumed by humans or livestock, or otherwise removed from the immediate
water environment…not available for other valuable purposes such as
public water supply, salinity repulsion in the Delaware estuary,
maintenance of streamflows, water quality, fisheries and recreation (http://www.state.nj.us/drbc/consdef.htm)
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Delaware River Basin Consumptive Use
|
Category |
1991 |
2000 |
2010 |
2020 |
|
Municipal |
203.4 |
228 |
255 |
284 |
|
Rural |
27.1 |
30 |
32 |
36 |
|
Industrial |
46.8 |
52 |
56 |
61 |
|
Power |
78.1 |
77 |
87 |
99 |
|
Agricultural Irrigation |
144.7 |
154 |
161 |
169 |
|
Golf Irrigation |
12.8 |
13 |
14 |
15 |
|
Institutions |
4.2 |
5 |
5 |
5 |
|
Livestock |
12.4 |
12 |
12 |
12 |
|
Ski Areas |
0.0 |
0 |
0 |
0 |
|
TOTAL |
529.5 |
571 |
622 |
681 |
Table 2: Estimated and Projected In-Basin Average Annual Consumptive Use (MGD)
|
Category |
1991 |
2000 |
2010 |
2020 |
|
Municipal |
114.0 |
128 |
143 |
159 |
|
Rural |
15.2 |
17 |
18 |
20 |
|
Industrial |
41.5 |
46 |
50 |
54 |
|
Power |
69.8 |
69 |
78 |
88 |
|
Agricultural Irrigation |
51.9 |
55 |
58 |
60 |
|
Golf Irrigation |
5.9 |
6 |
6 |
7 |
|
Institutions |
4.1 |
4 |
5 |
5 |
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Livestock |
7.2 |
7 |
7 |
7 |
|
Ski Areas |
1.2 |
1 |
1 |
1 |
|
TOTAL |
310.8 |
333 |
366 |
401 |
Table 3: Estimated and Projected Average Annual Exports and Imports of Water (MGD)
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Category |
1991 |
2000 |
2010 |
2020 |
|
Export |
796.8 |
907 |
910 |
910 |
|
Import |
32.1 |
42 |
42 |
42 |
Table 4: Total of In-Basin Average Annual Depletive Use Plus Net Exports of Water (MGD)
|
Category |
1991 |
2000 |
2010 |
2020 |
|
Total Net MGD |
1,076 |
1,199 |
1,235 |
1,270 |
Source: Delaware River Basin Commission, http://www.state.nj.us/drbc/tableii6.txt
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The
estimated total amount of water used each day in the watershed in 1991 was
7,337 MGD according to the DRBC (USGS NAWQA, 1999). |
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The
majority (69%) of that was used to generate power in New Jersey, and most
of the remaining water was used by the public (15%) and industry (15%).
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Most
of that water is used non-consumptively, meaning it is returned to the
basin's streams and aquifers, with the exception of about 311 MGD in
consumptive uses within the basin and 900 MGD that are diverted out of the
basin to New York City and northeastern New Jersey (USGS NAWQA, 1999). |
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PSE&G
in Salem, NJ is the largest of all surface water users within the
watershed, taking roughly 1,983 MGD (DRBC, http://www.state.nj.us/drbc/top10wd.txt). |
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The Philadelphia Water Department (PWD), which takes about 361 MGD from both the Delaware River (~50%) and the Schuylkill River (~50%), is the largest municipal user. (See Table 1.2.2-5). |