Page 340 - Water Loss Control

Contr olling Real Losses—Pr essur e Management 309

State L/per capita/per day Gal/per capita/per day
New York 450 119
North Carolina 254 67
North Dakota 326 86
Ohio 189 50
Oklahoma 322 85
Oregon 420 111
Pennsylvania 235 62
Rhode Island 254 67
South Carolina 288 76
South Dakota 307 81
Tennessee 322 85
Texas 541 143
Utah 825 218
Vermont 303 80
Virginia 284 75
Washington 522 138
West Virginia 280 74
Wisconsin 197 52
Wyoming 617 163
Puerto Rico 182 48
Virgin Islands 87 23
United States Total 397 105

TABLE 18.1 Estimated Per Capita Consumption in the United States (Continued)
requirements. Some of the most common forms of pressure management are discussed in
the following sections of this chapter.

18.3.1 Sectorization
Sectorization is one of the most basic forms of pressure management, which is still very
effective. Subsectors are divided either naturally or by physical valving. The sectors are
usually quite large and often with multiple feeds, therefore they do not usually develop
localized hydraulic problems because of valve closures. Systems with gravity feeds
usually sectorize by ground level and systems with pumped feeds usually sectorize
depending on the level of elevated tanks or storage.
One of the hardest parts about controlling pressure solely by using sectorization is
enforcing boundary valve control. Nowadays telemetry devices are available which
transmit valve status to a central control every time the valve is operated, therefore
allowing managers to control the integrity of the sectors and ensuring that they are
returned to normal after either an emergency or maintenance procedure.