Developing Integrated, Long-Term Water Supply Plans through Conservation, Drought Contingency, and Variable Service Capacities

摘要

In areas of the north central United States, climate variations and changing seasons present a unique set of challenges to municipalities with respect to meeting water demands. The use of water resources prone to both flooding and drought on a cyclical and seasonal basis requires an innovative approach toward understanding water use rates and developing strategies to meet the anticipated continuation of past population and economic growth trends to avoid future water supply shortages. As a result, water utilities are charged with developing sufficient supply and system capacity to meet increasing water demands during drought conditions, often in the absence of affordable alternative water resources. To alleviate the strain associated with a limited water supply and a growing population, water systems need to consider implementing adequate system capacity expansions along with prudent on-going water conservation and demand reduction strategies during drought conditions. For larger communities (around 100,000 people) experiencing growth in the eastern Dakotas, available water resources are generally of poor quality and/or insufficient quantity during relatively short periods of drought, where extremely low flow conditions are possible over the course of a couple seasons of dry weather. Such systems have adopted a balanced approach of integrating reasonable water supply planning and demand management strategies. This manuscript provides an understanding of the challenges associated with managing consumer expectations related to shifts in climate (dry versus wet weather patterns). The efforts of two communities are reviewed to demonstrate adopted strategies to meet water supply projections over 50-year planning periods. Strategies of discussion include water conservation program promotions, the enforcement of water demand reduction policies per drought indicator monitoring, the optimization of local supplies, and participation in regional water systems to obtain additional capacity at an affordable rate. The thought process behind an integrated approach toward water supply management and water demand management are discussed, as are specific steps taken by the example communities to balance water conservation and drought contingency planning efforts with supplemental water supply capital improvements. Through successful implementation, it is anticipated that the example communities will simultaneously