*TM 5-813-1/AFM-88-10, Vol. 1
CHAPTER 6
SURFACE WATER SUPPLIES
geographically and seasonally. Streams, in particular,
6-1. Surface water sources
often exhibit fairly wide seasonal fluctuations in mineral
Surface water supply sources include streams, lakes,
quality, principally as a result of variations in stream flow.
and impounding reservoirs. Large supplies of surface
In general, streams and lakes east of the 95th meridian,
water are generally available throughout much of the
which includes most of Minnesota, Iowa, Missouri,
eastern half of the United States where rainfall averages
Arkansas, Louisiana, and States east thereof, exhibit
about 35 inches or more annually and is reasonably well
dissolved mineral solids in the range of 100 or less to
distributed through the year. On the other hand, good
about 700 milligrams per liter (mg/l). The water from
surface water sources are much more limited in many
these sources, after conventional treatment in a well-
western regions with the exception of the Pacific
designed filtration plant, will meet standards prescribed
Northwest, where surface water is plentiful.
for potable water (see appendix A of TM 5-8133/ AFM
88-10, Vol. 3, for these standards). Unusual local
6-2. Water laws
conditions; e.g., pollution, may render some eastern
Any investigation directed toward development of new or
waters unsuitable as a source of supply; but in general,
additional sources of supply must include consideration
eastern streams and lakes are a satisfactory raw water
of applicable State water laws. Most of the States in
source. Similar comments are applicable to surface
roughly the eastern half of the United States follow the
waters of the Pacific Northwest area. Streams in many
riparian law of water rights, and only a few have permit
other areas west of the 95th meridian are much less
systems. Under this doctrine, the right to use water is
satisfactory, often showing dissolved mineral solids in the
associated with ownership of the land through which the
range of 700 to 1,800 mg/l. High concentrations of
stream flows. The riparian rights doctrine is essentially a
hardness-producing and other minerals such as sulfate
legal principle which may be used, in some form, to
and chloride are found in some western surface waters.
settle disputes. It does not automatically provide for
State water management and record keeping. Planning
6-4. Watershed control and surveillance
for water supply systems under the riparian doctrine is
Raw water supplies should be of the best practicable
not absolutely certain for present and future water
quality even though extensive treatment, including
availability and security. In contrast, western law is
filtration, is provided. Strict watershed control is usually
based largely on the doctrine of "prior appropriation." In
impractical in the case of water supplies obtained from
the 17 Western States where this doctrine prevails,
streams. However, some measure of control can be
sophisticated legal, administrative and management
exercised over adverse influences, such as wastewater
machinery exists. In these States, water rights and land
discharges, in the vicinity of the water supply intake. For
ownership are separable and most Western States
supplies derived from impounding reservoirs, it is
authorize a water-right owner to sell the right to another.
generally feasible to establish and maintain a control and
The new owner is permitted to transfer the water to
surveillance program whose objective is protection of the
another point of use or put it to a different use, provided
quality of raw water obtained from the reservoir. At
the transfer conforms to the State's administrative
reservoirs whose sole purpose is to provide a source of
requirements.
water supply, recreational use of the reservoir and
shoreline areas should be rigorously controlled to protect
6-3.
Quality of surface waters
the water supply quality.
The
quality of stream and
lake
waters
varies
6-1
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