Analysis of the Surface Drinking Water Provided By Intermittent, Ephemeral, and Headwater Streams in the U.S. Completed by U.S. EPA in July 2009


Analysis of the Surface Drinking Water Provided By Intermittent, Ephemeral, and Headwater Streams in the U.S.
Completed by U.S. EPA in July 2009
The objective of this study is to illuminate regional patterns of dependence on intermittent, ephemeral and headwater streams (I/E/H) for water that supplies public
surface drinking water systems in the continental United States. This was accomplished by analyzing the stream types found in Source Protection Areas (SPAs). A
SPA is the area upstream from a drinking water intake that provides water to a public drinking water system during a 24 hour period. Each system serves a specific
population, based on county. The percent of streams in SPAs that are I/E/H was calculated by determining the proportion of I/E/H out of all the stream miles
contained in the mapped SPAs for each geographic unit. "Total Population Served" is the sum of all populations served by public drinking water systems for that
unit whereas the "Population Dependent" includes only populations for those systems fed by SPAs containing I/E/H waters. AK and HI excluded due to lack of data.
Data Sources: National Hydrography Dataset at medium resolution and the Federal Safe Drinking Water Information System (4th Quarter 2006).
State
Total Population
Served by Public
Drinking Water
Systems using
surface water
Population
Dependent on
Public Drinking
Water Systems
relying on I/E/H
% Population
Dependent on
Public Drinking
Water Systems
relying on I/E/H
Total stream Miles
in Source
Protection Areas
Miles of
Intermittent
/Ephemeral
/Headwater in
SPAs
% of streams in
SPAs that are
Intermittent
/Ephemeral
/Headwaters
Miles of
Headwaters
in SPAs
Miles of
Intermittent
/Ephemeral in
SPAs
Miles of
Perennial
streams in
SPAs
TOTAL
124,364,960
117,447,743
94%
357,403.5
207,476.4
58%
178,442.5
122,907.8
169,527.2
AL
2,705,859
2,681,327
99%
10238.8
5,552.2
54%
5418.6
2353.7
6077.4
AR
948,185
941,225
99%
7854.0
5,088.7
65%
4427.8
4393.5
2407.6
AZ
3,254,601
3,254,601
100%
8101.3
6,381.3
79%
3156.4
6233.1
163.9
CA
7,320,360
7,314,715
99.92%
32688.3
18,592.2
57%
13523.3
13321.1
10470.0
CO
3,866,332
3,772,743
98%
16894.9
10,509.9
62%
8511.0
7473.0
6895.1
CT
2,241,030
2,241,030
100%
1431.9
844.8
59%
843.2
86.9
1076.8
DE
281,400
281,400
100%
344.4
183.6
53%
183.3
68.1
247.4
FL
1,808,955
1,808,955
100%
2597.7
580.2
22%
472.8
261.6
647.6
GA
4,918,344
4,912,944
99.89%
9897.6
5,557.1
56%
5477.2
2710.5
6204.5
IA
667,428
667,428
100%
3810.5
2,318.5
61%
1938.4
2039.1
991.2
ID
252,026
252,001
100%
8043.0
4,815.5
60%
4078.5
2866.4
3908.4
IL
4,872,325
1,680,948
34%
9894.4
5,687.5
57%
4832.6
4781.8
3335.6
IN
1,951,112
1,703,230
87%
2329.9
1,157.7
50%
1103.2
422.4
1420.3
KS
1,504,285
1,503,521
99.95%
7912.9
5,351.1
68%
4307.7
5007.0
2132.2
KY
3,282,980
3,282,980
100%
15064.8
8,184.7
54%
7923.8
3849.4
8933.0
LA
1,901,559
1,886,783
99%
4405.0
1,163.4
26%
990.5
518.0
1245.4
MA
5,009,161
4,915,909
98%
2636.0
1,413.0
54%
1396.1
216.5
1878.8
MD
3,990,271
3,990,016
99.99%
3993.5
2,210.1
55%
2195.7
560.9
2935.6
ME
456,041
454,360
99.63%
2306.3
1,264.8
55%
1255.8
206.2
1478.1
MI
1,977,536
1,400,633
71%
1342.1
550.8
41%
460.6
461.3
476.1
MN
1,068,598
978,928
92%
1736.4
627.2
36%
499.2
353.7
514.4
MO
2,498,142
2,498,142
100%
10114.6
6,310.8
62%
5193.5
5675.9
2918.5
MS
110,041
110,041
100%
347.0
209.9
61%
180.6
193.2
122.1
MT
351,401
234,219
67%
5873.3
3,594.9
61%
2192.4
2983.8
1456.9
NC
4,722,950
4,719,825
99.93%
13155.8
7,391.8
56%
7240.2
2755.3
8929.3
ND
292,414
292,414
100%
2637.2
1,498.2
57%
887.8
1399.6
547.2
NE
525,566
525,566
100%
695.3
370.9
53%
295.7
299.9
160.1
NH
503,657
503,196
99.91%
2340.7
1,310.6
56%
1272.8
377.8
1665.9
NJ
4,258,089
4,258,089
100%
2391.0
1,157.4
48%
1147.8
119.8
1868.9
NM
281,206
280,906
99.89%
2974.4
1,995.5
67%
1306.3
1792.0
625.0
NV
23,792
23,792
100%
48.8
40.0
82%
4.5
35.5
11.7
NY
11,471,432
11,146,815
97%
10436.4
5,728.4
55%
5668.0
518.5
7698.3
OH
5,894,716
5,285,318
90%
11604.9
6,977.7
60%
6471.4
4908.0
5386.2
OK
2,326,616
2,326,616
100%
8092.1
5,330.2
66%
4545.0
4387.5
2291.3
OR
1,782,414
1,770,246
99%
16029.3
9,134.4
57%
8393.0
2527.0
11289.7
PA
8,215,216
8,035,216
98%
18604.4
10,720.0
58%
10487.3
4678.2
11909.6
RI
580,332
564,893
97%
270.5
169.2
63%
169.2
33.2
172.0
SC
1,933,219
1,933,219
100%
5660.2
2,887.7
51%
2825.3
883.7
3726.1
SD
309,421
309,421
100%
2117.3
1,326.9
63%
962.6
1173.5
277.7
TN
3,573,078
3,572,494
99.98%
18464.4
10,584.8
57%
10478.1
1100.8
15043.7
TX
11,674,641
11,557,744
99%
20482.9
12,570.2
61%
9546.0
10877.9
4284.2
UT
1,490,700
1,428,450
96%
6515.3
4,441.5
68%
3169.5
3744.4
1805.5
VA
2,369,620
2,364,709
99.79%
9260.2
5,290.2
57%
5158.6
2721.4
5629.8
VT
181,226
181,226
100%
1820.2
951.4
52%
951.0
45.7
1309.0
WA
2,110,490
2,002,833
95%
11438.5
6,355.0
56%
5139.2
3455.0
5541.5
WI
1,392,700
391,531
28%
504.3
253.8
50%
228.5
137.4
62.0
WV
1,007,781
1,002,731
99.50%
14824.9
8,387.1
57%
8205.7
4455.3
9012.7
WY
205,712
202,414
98%
7175.9
4,453.7
62%
3326.9
3443.3
2343.0

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