WMOD00438

• Title: HIPLEX: A Cooperative Program on Rain Augmentation in the High Plains
• Date: 6/1/1984
• Weather Modification - Doc Type: Report

2. HIPLEX OVERVIEW

2.1 Introduction

The High Plains Region stretches from south central
Texas through the center of the Nation to eastern
Montana. It includes parts of New Mexico.
Oklahoma. Kansas. Nebraska. Colorado. Wyoming.
South Dakota. and North Dakota (fig. 2.1). The eco-
nomic base of the region is agricultural. but unlike
farming areas to the east which enjoy an average
annual rainfall of 750 to 1500 mm (30 to 60 in).
rainfall in the High Plains averages only 350 to
500 mm (14 to 20 in) per year. Even with the use of
good dry-farming methods. crop yields are incon-
sistent and often result in a "boom or bust" eco-
nomy. In a region where 2 or 3 of every 4 years are
parched. farming is indeed a gamble.

Irrigation water from reservoirs or pumped from
Plains aquifers has been used to stabilize the agricul-
turaleconomies and provide needed water supplies
to town and cities. Pumping. while useful and reason-
ably effective in the "short run." may actually create
more serious problems than it solves. It is a very
expensive undertaking. both in terms of the dollars
required to support the method as well as in terms
of the rapid consumption of ,a limited resource. In
many areas of the High Plains region. water levels in
the underground aquifers have dropped 30 m
(100 ft) or more since extensive pump irrigation
began over three decades ago. Natural recharge of
the aquifer is negligible. yet the demand for water
for agriculture. municipal. industrial. and recreational
use continues to grow (High Plains Associates.
1982).

. Thus the problem of water supply and demand
throughout the High Plains is twofold: a timely water
supply for crops is needed in an environment where
rainfall is. at best. uncertain. and depletion of the
existing underground water supplies. which is occur-
ring at an alarming rate. must be slowed or stopped.

Figure 2.1- The High Plains Region. Weather Modification may
provide a solution to water shortages in the High Plains.

Clearly. dependable alternate sources of water are
needed beyond that currently provided by rainfall or
pumped from the ground.

There are alternatives which may lead to a solution
(High Plains Associates. 1982). Among them. contin-
ually evolving methods of more effective water con-
servation. importation. reservoir storage. flood
control. and cloud seeding show promise. A combi-
nation of some or all of these methods will be needed
to increase the supply of surface wateir, reduce the
now heavy demand on aquifers. and eVlmtually result
in a stable water situation for the sl3miarid High
Plains.

2.2 Weather Modification and the Origin
of Hiplex

Among the possible solutions to High Plains water
shortages noted above. weather modification has
the advantages of being inexpensive while promising
immediate benefits. Therefore. there has been
interest in weather modification for rain stimulation
in the High Plains from the time modern cloud seed-
ing methods were introduced by commercial opera-
tors in the early 1950's. Numerous weather
modification projects have been conducted in the
High Plains. most of which have involved attempts
to increase rainfall by seeding convective clouds.
which are common in early summer and which con-
tribute much of the total annual precipitation. In
addition to these operational projects. an extensive
series of experimental projects was carried out by
the Bureau of Reclamation as part of "Project
Skywater." The results from these early Skywater
experiments were not considered conclusive enough
to justify the routine adoption of weatlher modifica-
tion technology by Federal agencies. Indications
were that economically important benefits might be
obtained. but the risk of failure or of undesirable side
effects had not been sufficiently quantified.

In 1973. the OMB (Office of Management and Bud-
get) directed the Bureau of Reclamation to launch a
program to reduce scientific uncerUlinties asso-
ciated with attempts to increase rainfall in the High
Plains through cloud seeding. The Bureau was
further directed "to maximize the scientific values of
this research" in an effort to permit more rational
decisions regarding the Government's role in the
application of weather modification technology.

The Bureau's response to the directive was HIPLEX,
which was developed and conducted in close coop-
eration with State and local Governments in the High
Plains Region. The efforts of these agencies were
joined from the outset by the Canadian Government.

Although launched as a specific program by the.
1973 OMB directive. HIPLEX constituled a contin-

5