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Show * water consumption whether the weather is wet or dry." Program participants represent about 90 percent of the state's urban population. Savings of 500,000 acre- feet by the year 2000 and 1,000,000 acre- feet by the year 2010 are estimated. A series of " best management practices" in the program include public information campaigns, school education programs, water audits for houses, new and retrofit plumbing to increase the use of efficient showerheads and toilets, and conservation pricing. These efforts are expected to use current supplies more fully in the future as the population grows. But in spite of the anticipated water savings, new water supplies will also be needed. One of the significant findings of the above efforts is that, "... by promoting greater conservation, many cities may become increasingly vulnerable to future droughts because there won't be a margin of safety in water use. This makes development of additional reliable supplies even more important." 17.4.4 Restricting Water Use To make enough water available for necessary household and commercial use during periods of severe drought, the use of municipal water for lawn and garden watering and other outside uses has periodically been restricted in Utah as in 1977. One of the easiest restrictions to monitor and enforce is to prohibit outside use during times of the day or days of the week. In the most severe cases, all outside use has been temporarily prohibited. The public has accepted these restrictions when they understand the necessity and realize the situation is temporary. But it is doubtful the public would accept such restrictions if they are perceived to be unnecessary or artificially contrived. Because of the loss of water to evaporation on hot summer days, some water districts prohibit lawn watering between the hours 10 a. m. to 6 p. m. The estimated loss from evaporation during the day is 10 to 15 percent of the applied water. Programs restricting the use of secondary water during daytime summer hours have been established by several cities. Water suppliers consider this program a large success and it has been well received by customers. Restriction of daytime watering is a recommendation of the Utah Water Conservation Advisory Board and could be implemented in the Jordan River Basin. At the present time, the greatest threat imposed during extended hot, dry periods is not inadequate supply but rather a deficient infrastructure which is incapable of delivering a flow sufficient to meet peak demand. Consequently, during hot summer days, demand can result in insufficient flows, low water pressure, inadequate fire flow capacity, and back- syphoning or negative pressures that can cause structural damage to the system. Experience has shown outside watering restrictions to be an effective tool in reducing peak demand. In fact, even when watering restrictions have failed to reduce the total water use, they have still proven effective in reducing peak demand. Consequently, water purveyors will continued to implement outside watering restrictions or other measures to help deal with peak demand. 17.4.5 Conjunctive Use Conjunctive use of water supplies ( also called " joint use") most often refers to surface water and groundwater. Where both are available as a water supply, groundwater can be allowed to accumulate during wet years, and then pumped in dry years to supplement surface water supplies. This is an excellent example of wise use because it manages the total water supply, maximizing system efficiency. Similarly, treated and untreated water can be used jointly to conserve water as well as reduce costs. A secondary system to distribute untreated water for lawns and gardens allows use of a smaller system capacity of expensive treated water. A substantial portion of high- quality treated water in public systems is customarily used for lawn and garden watering. 17.4.6 Landscaping and Home Water Savings Reductions in per capita use of municipal water requires changes in personal habits and traditional practices inside and outside the home. This requires a public perception of need, but it can produce significant savings. • Inside, users can install water- saving toilets and shower heads, check plumbing for leaks, take shorter showers, use automatic dishwashers and washing machines only for full loads, and avoid having faucets run long periods for shaving or rinsing vegetables, dishes and other items. • Outside, users can avoid using a hose to clean driveways and stop letting water run constantly while washing a car. Landscaping practices can also be improved. The Division of Water Resources teaches and encourages 17- 5 |