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CHAPTER 4

INTAKE FACILITIES

Steven N. Foellmi
Black & Veatch
Irvine, California

Intakes are structures built in a body of water for the purpose of drawing water for hu-
man use. As discussed in this chapter, intake systems include the facilities required to di-
vert and transport water from a supply source, such as a river, lake, or reservoir, to a shore
well or pumping station. For small water supplies, the intake system may be relatively
simple, consisting of little more than a submerged pipe protected by a rack or screen. In
contrast, for major water supply systems, intake systems can be extensive, with diversion
accomplished by intake tower structures or submerged inlet works. An intake system may
also include transmission conduits, screens, pumping stations, and, in some instances,
chemical storage and feed facilities. This chapter presents a brief review of intake fea-
tures, describes types of intake systems, and provides a discussion of intake design con-
siderations. The design of racks and screens is also discussed.

INTAKE FEATURES

The purpose of an intake system is to reliably deliver an adequate quantity of water of
the best available quality. Reliable intake systems are costly and may represent as much
as 20% of the total water treatment plant investment. Pipeline construction associated with
intakes may involve extensive underwater work and the use of specialized marine equip-
ment. As a result of these and other factors, the cost of such work would be 2.5 to 4 times
more than that for a similar land project. An intake system must possess a high degree of
reliability and be able to supply the quantity of water demanded by a water utility under
the most adverse conditions. Intakes are exposed to numerous natural and artificial per-
ils, and it is important that the designer anticipate and make provision for operation un-
der adverse conditions. Conservative structural and hydraulic design and careful selection
of intake location should be priority considerations. Changing and increasingly stringent
drinking water regulations present new challenges that potentially impact the design of
intake facilities. Application of chemical treatment at the intake facilities may be advan-
tageous to achieve water quality or treatment goals. Problems associated with zebra mus-
sels provide additional challenges to intake system design.

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