The new Diamond Valley Lake Reservoir near the city of Hemet in
Riverside County is billed as the largest earthworks construction
project in U.S. history. Construction began in 1995 and involved 31
million cubic meters of foundation excavation and 84 million cubic
meters of embankment construction. This set of Multi-angle Imaging
Spectroradiometer (MISR) images captures the
most recent phase in the reservoir's activation. At the upper left is a
natural-color view acquired by the instrument's vertical-viewing (nadir)
camera on March 14, 2000, shortly after the
Metropolitan Water District began filling the reservoir with water from
the Colorado River and Northern California. Water appears darker than
the surrounding land. The image at the upper right was acquired nearly
one year later on March 1, 2001, and shows a clear
increase in the reservoir's water content. When full, the lake will hold
nearly a trillion liters of water.
According to the Metropolitan Water District, the 7 kilometer x 3
kilometer reservoir nearly doubles Southern California's above-ground
water storage capacity. In addition to routine water management, Diamond
Valley Lake is designed to provide protection against drought and a
six-month emergency supply in the event of earthquake damage to a major
aqueduct. In the face of electrical power shortages, it is also expected
to reduce dependence on the pumping of water from northern mountains
during the high-demand summer months. An unexpected result of site
excavation was the uncovering of mastodon and mammoth skeletons along
with bones from extinct species not previously thought to have been
indigenous to the area, such as the giant long-horned bison and North
American lion. A museum and interpretive center is being built to
protect these finds.
The lower MISR image, from May 20, 2001, is a
false-color view combining data from the instrument's 26-degree forward
view (displayed as blue) with data from the 26-degree backward view
(displayed as yellow). This technique enables bodies of water to stand
out prominently by taking advantage of the strong change in brightness
between the two view angles and the contrasting angular signature of the
surrounding land. The blue-yellow separation in the cloud field is due
to geometric parallax resulting from the clouds' elevation above the
surface terrain.
Each image covers an area measuring approximately 125 kilometers x 95
kilometers. The northwest to southeast trending linear feature is the
Elsinore Fault.
Image courtesy NASA/GSFC/LaRC/JPL, MISR Team