WMOD00176

• Project Name: Annual Report
• Title: Seeding Operations & Atmospheric Research, 2005 Annual Report
• Prepared By: Duncan Axisia
• Date: 12/31/2005
• Weather Modification - Doc Type: Report

9O-mlle radius of the SOAR field facility in
Plains. The portions of Eddy and Chavez
County that lie within the 9O-mile radius are
buffer zones for the target area in Roosevelt
and lea Counties.

The Southern Ogallala program target area
consists of a total acreage of 5.92 million The
Texas target area (Yoakum. Terry and Gaines)
consist of 204 million acres while the target
area in New Mexico within Roosevelt County
and lea County covers 387 million acres
During 2005. all three aircraft were based in
Plains Texas

The objective of weather m(xllflCation for
precipitation enhancement In the southern
plains of Texas and New Mexiro is to increase
rainfall and the recharge of groundwater.
increase soil moisture for agricuhure, and
reduce the water demands on ground and
surface water resources.

The Uano Estacado Region and the
need for precipitation enhancement

In 1997, Senate Bill 1 was enacted by the 75th
Texas legislature. which specified that near
and long-term water plans be developed for
regions of Texas. Senate Bill 1 empowered
the Texas Waler Development Board (TWOB)
to provide for the orderly development,
management. and ronservatlOn of water
resources and preparation for and response to
drought ronditions in order that sufficient water
will be available at a reasonable cost to protect
the agricuhural resources of that particular
region. In the South Plains of Texas. a 21-
county area was delineated by the TWOB as
Planning Area 0, which was subsequently
named the llano Estacado Regional Water
Planning Region. The SOAR Texas target
area is part of this planning area

The principal source of recharge to the
Ogallala Formation in the llano Estacado
Region is precipitation on the land surface. The
amount of recharge depends on many factors.
including the amount. distribution, and Intensity
of precipitation and the type of soil and
vegetative cover. The amount of recharge has
been estimated at from less than 0.5 inch
annually to about 3 inches annually

Precipitation is the only naturally
reoccumnglrenewable water supply for the
Llano Estacado Region. The average annual
precipitation received in the region IS 18.4
inches (1945 through 1997). which would be
19.915.179 acre-feet of water over the
12.988,16O-aO'e region. Precipitation meets
about 60 percent of urban landscape water
and irrigated crop demands. It provides all the
water for surface reservoirs and all the water
for rangeland and drytand crop productIOn.
PrecipitatIOn also prOvides water for wildlife
and natural recharge to the reglOn's aqUifers.

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Ftgure 5 . Cities Wlth needs based on cnnpanson of
QJrrent water SU~leS"Mth projected demands

The water needs (shortages) of the region
amount to about 6 percent of the projected
demand by 2020, increasing 10 7 percent of
demand in 2040 and 2050. This means that by
2050 the regkln would be able to supply only
93 percent of the projected waler demands
unless supply development or other waler
management strategies are implemented. The
Llano Estacado Regional Waler Planning
Group identified seventeen (17) waler
management strategies as potential strategies
to meet the projected needs of the region.
PrecIpitation enhancement or doud seeding is
one of them.

PrecipitatIOn enhancement has the potential to
increase the QuantIty of waler that would be
available to many water user groups in the
Llano Estacado Region, as well as reduce
pumpage requirements from the Ogallala

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