Geoscience Reference
In-Depth Information
Kesterson National
Wildlife Refuge
N
San Luis
Drain
OR
ID
Selenium
sources
Ca
l
if
California
lifo
lifornia
NV
NV
39°
N
39
N
39° N
UT
Panoche Creek
36° N
36°
N
6
AZ
126° W
12
6°
W
33° N
123° W
33°
N
Groundwater
transport of selenium
N
120° W
0
5
10 km
0
5
10 mi
Cantua Creek
(a)
(b)
(c)
Figure 20.18 Drain system in the San Joaquin Valley.
(a) Map of the San Luis Drain and Kesterson Reservoir. This system was used to
drain excess groundwater from farm fields in the valley, some of which contained high levels of selenium derived from the Coast Ranges.
(b) Photograph of Kesterson Reservoir. (c) Deformities in a bird chick linked to high levels of selenium in the water at Kesterson Reservoir.
and deaths. As a result of this environmental problem, the San
Luis Drain was closed in 1985. Amid much public outcry, it was
reopened in 1996 to receive limited amounts of drain water.
pay farmers hundreds of millions of dollars to take about 79,000
hectares (~195,000 acres) of the most sensitive farmland out of
production. Another idea is to build more than 2000 artificial evap-
oration ponds into which groundwater would drain and evaporate.
This method would concentrate salts at specific locations, which
could then perhaps be transported to the ocean and dumped. It
would require removing land from productivity, however, to create
room for the ponds. In the western part of the valley, for example,
it is believed that one pond is required for every nine fields. Still
other ways of coping are to treat the water with expensive technol-
ogy and to grow more salt-tolerant crops such as cotton.
Possible Solutions
Given the environmental problems as-
sociated with draining saline groundwater from the San Joaquin
Valley, environmental managers continue to look for a way to re-
duce soil salinity in the region. In the mid-1980s the United States
Geological Survey (USGS) took the lead in the search for new
and better ways to rid the valley of excess groundwater. A num-
ber of potential solutions continue to be discussed. One idea is to
