Summary of Water Demands 
Projected withdrawal demands increase 
for all the major end uses of water. By 
2040, thermoelectric steam cooling is 
projected to have the largest 
withdrawals, followed by irrigation. 
These two uses account for about 
three-quarters of water demand in 
2040. There will be large increases in 
demands for both ground-water and 
surface-water withdrawals. 
Total demands for freshwater 
withdrawals are expected to increase in 
all regions. The largest percentage 
increase in demand between 1985 and 
2040 is for the North, and the smallest 
percentage increase is for the Rocky 
Mountain region. 
Water Supplies 
Precipitation in the form of rain, snow, 
sleet, and hail is the source of both 
surface and ground water. Various 
management practices can affect local 
supplies, but the Nation’s annual 
supply of water is beyond direct 
control and depends on the forces of 
nature. 
Water Demand-Supply 
Comparisons 
It is apparent that precipitation 
provides enough surface and ground 
water (1.4 trillion gallons a day) to 
meet present and prospective 
withdrawals (some 500 billion gallons 
a day by 2040). By 2040, water 
consumption still amounts to only 10 
percent of precipitation. There are, 
however, serious imbalances caused by 
the geographic, seasonal, and annual 
variations in supplies. 
Water-quantity problems exist in the 
Rio Grande, upper and lower Colorado, 
20 
Great Basin, and California water 
resource regions. 
The water supply situation in some 
areas—such as the High Plains, which 
extends from central Texas and eastern 
New Mexico north into eastern 
Colorado, Kansas, and southern 
Nebraska—is being affected by 
ground-water mining. As a result of 
ground-water mining and rising energy 
costs, the use of ground water for 
irrigation over substantial areas may 
become uneconomic during the next 2 
decades or so. Demand-—supply 
situations in arid parts of the 
Southwestern United States are 
stimulating studies of ways to develop 
water markets. Such markets are 
mostly lacking under current 
institutional arrangements. 
Most of the Nation’s water shortages 
are caused by annual and seasonal 
variations in precipitation and water 
flows. Variations caused by unusual 
storms bring about another major 
problem—flooding. Flooding occurs in 
all parts of the United States. Flood 
damages are greatest in coastal and 
southern California, in a broad range 
extending up the Mississippi River 
drainage, and in another broad area 
extending up the Atlantic coast from 
South Carolina to Maine. 
Water quality will continue to be a 
concern under the projected 
demand-supply situation. For example, 
nonpoint sources of pollution are 
especially important for fish habitat 
and the composition of the fish 
community. These concerns will 
continue to be reflected in public 
policies aimed at management of water 
quality. 
Range Forage Demand- 
Supply—The Outlook 
Outlook Overview 
e Per capita consumption of beef, veal, 
lamb, and mutton 1s projected to 
remain near current levels during the 
coming decades. 
e Thus, future demand will grow in 
line with the growth in the total U.S. 
population. 
e After taking into account imports 
and exports, total demand on the 
domestic range forage resource 1s 
expected to increase 54 percent by 
2040. 
e Forage from public lands accounts 
for less than 10 percent of total forage 
consumption. 
e Management of Forest Service 
rangelands will be oriented to 
vegetation management, with multiple 
uses as the desired output mix. 
e [tis assumed that forage production 
on private lands will become more 
productive over time. 
e Thus, much of the current and 
prospective range forage supply 
situation depends on private lands. 
e Total supply of range forage is 
expected to increase 52 percent by 
2040, with most of the increase coming 
from private lands. 
e Multiple-use management of 
rangelands will be necessary to 
accommodate domestic livestock, 
wildlife, recreation, and other uses of 
rangeland. 
The Range Forage Resource 
The range forage resource consists of 
grasses, grasslike plants, forbs, and 
shrubs associated with rangeland and 
