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USE AND EFFECTIVENESS OF MUNICIPAL WATER RESTRICTIONS DURING DROUGHT IN COLORADO <br />for reservoir management but is also useful to com- <br />pare the efficacy of demand management strategies to <br />other means of reducing drought vulnerability, such <br />as through constructing new projects, purchasing new <br />water rights (or options on rights), constructing <br />wastewater reuse systems, and so on. For these types <br />of comparisons, water volumes are much more rele- <br />vant than percent reductions in customer demands. <br />Only for this reason are volumetric savings presented <br />in this study. <br />Table 4 provides estimated ranges of actual and <br />potential water savings in acre feet (equal to 325,851 <br />gallons) using the net use and expected use per capita <br />methods as upper and lower boundaries. The volume <br />of water saved is a function of total water deliveries <br />(i.e., the size of the water system), the percent savings <br />achieved through restrictions, and the type and dura- <br />tion of restrictions. Collectively, the eight providers <br />studied saved approximately 18,263 to 36,000 acre <br />feet of water during the four -month study period. To <br />put these values into perspective, 20,000 acre feet is <br />the typical annual water demand of a town of approxi- <br />mately 75,000 people (using the conservative assump- <br />tion of 0.27 acre feet per person) and has a retail (end <br />user) value of more than $13 million (assuming a typ- <br />ical rate of $2 per thousand gallons). <br />The potential savings could have been much <br />greater. Rough extrapolations suggest that had our <br />seven providers with mandatory restrictions utilized <br />their programs for the entire four -month study peri- <br />od, total savings likely would have ranged from <br />32,491 to 48,998 acre feet. Furthermore, if all eight <br />providers had used the twice a week watering sched- <br />ule and achieved the 30 percent average level of sav- <br />ings seen for this approach in this study, water <br />savings could have totaled 64,483 to 76,784 acre feet. <br />Using the same logic, the more aggressive once a <br />week schedule could have potentially translated into <br />113,920 to 130,301 acre feet of savings had this <br />approach been used in mandatory programs over the <br />four -month period. <br />Translating Drought Savings to Long Term <br />Conservation Potential. These potential savings <br />estimates provided above are admittedly very rough <br />and should be used judiciously; nonetheless, they sug- <br />gest a potential for demand management in the <br />region that is perhaps not confined merely to drought <br />emergencies. In the absence of drought, the cities of <br />Colorado's Front Range may want to consider adopt- <br />ing outdoor watering restrictions on a permanent <br />basis as part of a long term conservation program. <br />This is already done in Castle Rock (just south of <br />Denver), which has utilized the every third day <br />watering schedule since 1996. <br />There are several reasons, however, to use caution <br />in assuming that demand management savings dur- <br />ing drought could be sustained during nondrought <br />periods. Specifically, the savings experienced were <br />largely the result of cooperation and "goodwill" on the <br />part of citizens and represented a "belt tightening" <br />that was publicly acceptable given the emergency con - <br />ditions but perhaps unacceptable if adopted as a nor- <br />mal part of management. Additionally, to the extent <br />that some water savings were, in part, due to man- <br />agement decisions to postpone system flushing and <br />maintenance, to limit water applications on public <br />parks, and other emergency drought coping measures, <br />it would be dangerous to assume that these savings <br />could be achieved on a permanent basis. <br />It should also be noted that any effort to reduce <br />waste in the system could have the effect of reducing <br />the "drought cushion" that allows cities the flexibility <br />of drought year conservation savings although that <br />cushion could likely be provided in other ways, such <br />as through an expanded use of dry year options with <br />the agricultural sector (Nichols et al., 2001; Luecke et <br />al., 2003). This threat becomes real if the water con- <br />served goes to support new growth rather than being <br />held in reserve for drought emergencies. The relation- <br />ship between water management and growth is <br />beyond the scope of this paper as well as beyond the <br />control of water managers, but it is nonetheless part <br />of the context that must be considered when describ- <br />ing the relationship between drought coping and long <br />term conservation. In any case, further research is <br />warranted regarding the ability to translate drought <br />savings into permanent conservation savings. <br />SUMMARY AND RECOMMENDATIONS <br />This study indicates that outdoor watering restric- <br />tions, particularly mandatory programs, are an effec- <br />tive means of reducing water demand during drought <br />periods among Colorado's Front Range municipalities. <br />While this conclusion is evident regardless of the <br />means used to calculate savings, the expected use per <br />capita methodology yields the greatest savings and is <br />a particularly useful approach for measuring the <br />effectiveness of water restrictions from the standpoint <br />of the end users (i.e., residents) dealing first -hand <br />with the impacts of drought on residential landscap- <br />ing. <br />As expected, the level of water savings increases as <br />the frequency of permitted watering days declines <br />and as time limits (per zone) are tightened. The dra- <br />matic jump in savings achieved by cities using the <br />twice a week regime compared to the marginally more <br />JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION 85 JAWRA <br />