Urban Drought Planning vs. the Real Thing

The Washington, D.C. metropolitan area is supplied by three major utilities serving a total population of 3.6 million people. Planning for drought in the Washington, D.C. metropolitan area has been conducted for decades. In addition to the structural alternatives studied, an academic exercise conducted largely at the Johns Hopkins University in collaboration with the Interstate Commission on the Potomac River Basin concluded that gains from coordinated use of existing water resources would meet demands projected for the region well into the 21^st century. The results of that essentially non-structural alternative were adopted as operating rules in 1982. Planning for drought has continued with the refinement and exercise of these regionally adopted rules for coordinated operations of the Potomac River and associated supply reservoirs. Water supply conditions during the summer of 1999 necessitated the first use of the full range of resource operations to meet municipal and environmental needs. Experiencing the real thing presented some unexpected challenges. Creative management strategies were required because the extremely low flow conditions in the river caused releases from upstream storage to take longer to get to the intakes than expected. And at times, they also exceeded demands because intermittent rains that fell unpredictably. Thus, the inefficiency of river regulation was encountered first hand. Recently completed variable yield analysis to assist the operation of the direct supply reservoirs was incorporated to quantify the risks involved in temporarily exceeding reliable yields. Briefings for an extraordinary number of hastily called meetings and responses to questions from all branches of the media consumed an unanticipated amount of time and resources; especially after mandatory restrictions were imposed in a jurisdiction served by only one of the regional utilities.