Water Conservation Begins With...
|Water is the lifeblood of the West -- the crucial commodity. The
region's development from a thousand years ago to today has been tied to
the availability of water.
Water supply varies greatly from season to season and from year to year,
and water is often located great distances from where it is needed.
Snowmelt from winter accumulations in the high mountains is the source
of about 75 percent of the region's water supply. Typically, irrigators
and communities collect, store, and transport water to regulate quantity
and ensure availability when and where it is required. With about 40
million acres under irrigation, modern agriculture together with the
pressures of a rapidly expanding society make heavy demands on this
|Early westerners realized the ties
between the size of the winter snowpack in the high mountain ranges --
Rockies, Cascades, Sierra Nevada -- and their summer water supply. Some
attempts to measure the snow and predict runoff had been made in the
East as early as 1834, but it wasn't until 1904 that a systematic survey
was undertaken in the West. Dr. James Church, a classics professor at
the University of Nevada in Reno, made surveys on Mt. Rose in the Sierra
Nevada. He developed measuring equipment and sampling techniques that
led to the first water supply forecasts. Success in Nevada soon spread
to other states and agencies. By 1935, at least nine independent snow
surveys were being conducted.
||Drought is a part of life in the West.
In 1934, a particularly severe drought resulted in farmers demanding
better predictions of the streamflows available for growing crops.
Others who counted on water for industry, power generation, and domestic
use echoed this request. Congress responded in 1935 by passing
legislation creating a federal snow survey and water supply forecasting
program under the direction of the Bureau of Agricultural Engineering in
the Department of Agriculture. In 1939, the bureau was transferred to
the Soil Conservation Service (SCS); this agency, now known as the
Natural Resources Conservation Service (NRCS), continues to direct a
cooperative federal, state, and private snow survey program. The
National Weather Service is a major cooperator with NRCS in making these
water supply forecasts. Today, forecasts are routinely issued for over
700 locations in the West.
|Manual surveys, similar to those
initiated by Dr. Church and performed by teams of trained surveyors,
have been the backbone of the measurement network. With the advent of
mechanized oversnow machines and aircraft, the surveyor's task has been
eased somewhat, but snowshoes and skis are still required to reach many
remote sites. Periodic measurements at some 800 snow courses provide the
insight into snowpack accumulation patterns. Forecasters still use this
information advantageously, but more frequent data are needed to improve
the accuracy and timeliness of forecasts. Various methods of remote data
acquisition have been tested, including conventional line-of-sight radio
telemetry, satellite based telemetry, and a new technique called meteor
||Meteor burst telemetry relies on the
physical phenomenon that enables radio signals to be reflected off
ionized meteorite trails 50 - 75 miles above the earth's surface.
Utilizing this principle, sites as far apart as 1200 miles can
communicate with one another for very short periods ranging from
fractions of seconds up to several seconds. This interval is
sufficiently long to "burst" relatively short data messages between
sending and receiving stations. This method of communications is ideally
suited for interrogating remote data sites on a schedule of several
polls per day. The interference that mountains often cause in
conventional communications is not a problem for a meteor burst system.
|In 1977, NRCS began modernizing its snow surveys by introducing
meteor burst technology for acquiring snowpack data. The project, called
SNOTEL (for SNOwpack TELemetry) measures and transmits snowpack,
precipitation, and temperature data on a daily (or more frequent) basis
throughout the West. A snow "pillow" serves as a hydraulic weighing
platform to measure the snow water content.
Over 700 SNOTEL sites are
in operation. Most sites are powered by solar panels and are visited
only a few times each year. Data are transmitted by meteor burst to a
master station in Boise, Idaho, or Ogden, Utah, and then automatically
forwarded by telephone to a central computer in Portland, Oregon.
Hydrologic data gathered from the SNOTEL system, snow course network,
and other climatological stations are assembled in the computer system
at the National Water and Climate Center in Portland, Oregon, for
analysis and interpretation. A series of computer programs, known
collectively as the Centralized Forecasting System (CFS), is the
analytical tool used to generate streamflow forecasts, data summaries,
and narratives that describe the current water supply outlook. This
information is made immediately available to NRCS offices and other
interested users via the Internet or by dial-up modem.
|Water supplies are no longer a mystery thanks to this systematic
snowpack inventory and monitoring program and advanced computer
technology. Managers are alerted early in the water year to expect
normal flows, water shortages, or floods, and they can make plans while
there is still time to take effective action. Snow surveys and water
supply forecasting do not create water, but they do the next best thing:
They provide the tools for conservation of this most precious of the
West's resources. For more information on this program, contact your
local conservation district or NRCS office.