PUB00012

• Year: 1999
• Title: Sustainability of Ground-Water Resources: U.S. Geological Survey Circular 1186
• CWCB Section: Interstate & Federal
• Author: William M. Alley, Thomas E. Reilly, O. Lehn Franke
• Description: Illustration of the hydrologic, geologic, and ecological concepts to assure wise and sustainable use of ground-water resources
• Publications - Doc Type: Historical

declines (Figure IDA) and decreased the saturated
thickness of the aquifer significantly in some
areas (Figure lOB). These changes are particularly
evident in the central and southern parts of the
High Plains.

The southern part of the High Plains
aquifer in Texas and New Mexico slopes gently
from west to east, cut off from external sources of
water upstream and downstream by river-carved
escarpments, as shown in Figure lIA. Thus,

A

.re'

'00'

~'

rj"
, .
~
"I;
y
COLORADO

(~
.2
~
\2

--.-----\---

OKlAHOMA ~

".

EXPLANATION

Waler-Ievelchange,
Inleet
Declines
_ Morethan150
_ 10010150
_ 5010100
l:il!I 101050
Rises
_ Morelhan10
c Lesslhanlo-foot
change
- BoundsI)' olthe
High Plains aquifer

NE\I,' MEXICO

150MILES
. ,
150KILOMETERS

ground-water recharge is due almost exclusively
to areal recharge from precipitation. Although
precipitation in the area is 15 to 20 inches per year,
only a fraction of an inch recharges the aquifer due
to high evapotranspiration from the soil zone.
During predevelopment conditions, discharge as
seeps and springs along the eastern escarpment
equaled recharge. Today, the magnitude of natural
recharge and discharge is small compared to with-
drawals for irrigation.

B

'W

'00'

"

~.

EXPLANATION
Saturated-thickness
change, In percent
Decreases
_ Morelhan50
_ 251050
iii! 101025
Increases
. Morethanl0
CJ Le8sthanl0-percent
change
- Boundary olthe
High Plains aquifer

o
I
o

150MILES
150KllOMETEAS

Figure 10. Changes in (A) ground-water levels and (B) saturated thickness in the High Plains aquifer from
predevelopment to 1997. (V.L. McGuire, U.S. Geological Survey, written commun., 1998.)

Extensive pumping of ground water for irrigati011 has led to ground-water-level declines in excess of 100 feet
in parts of the High Plains aquifer in Kansas, New Mexico, Oklahoma, and Texas. These large water-level
declines have led to reductions in saturated thickness of the aquifer exceeding 50 percent of the predevelopment
saturated thickness ill some areas. Lower ground-water levels cause increases in pumping lifts. Decreases in satu-
rated thickness result in declining well yields. Surface-water irrigation has resulted ill water-level rises in some
parts of the aquifer system, such as along the Platte River in Nebraska.

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