Agenda - 04-17-2001-9g - Laserfiche WebLink

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For the past two years, OWASA staff have participated in active discussions with staff of both Durham and Chatham County about potential joint ventures in withdrawal, transmission, and treatment facilities, including the possible creation of a Jordan Lake water development authority. We have kept the OWASA Boazd of Directors well apprised of these discussions and opportunities, but they have not yet benelited from a full discussion with other leaders of the community, so it is premature to speculate on their eventual outcome. OWASA will provide more detailed plans to the Environmental Management Commission (EMC) for its use of Jordan Lake water as these options.aze more fully developed in the months to come. The OWASA Board has discussed the application process extensively and requests that I convey their keen interest in retaining a substantial portion of our 10 MGD Level II allocation. A critical element of OWASA's mission of providing an adequate supply of high quality drinking water has been maintaining a reliable range of long-term options for the future. Jordan Lake has always represented an important hedge against an uncertain future -and, as you well know - future water supply and demand scenazios are subject to major unknowns and uncertainties. Changes in underlying conditions or assumptions on which forecasts aze based can result in radical changes to future scenarios. The Board of Directors has asked me share with you same of the major uncertainties inherent in OWASA's future supply and demand scenarios: Service Area Growtli and Demand -Our demand forecasts aze based on an array of specific expectations, including the assumption that OWASA's service area, defined as the Urban Services Area delineated in the Carrbora-Chapel Hill-Orange County Joint Planning Agreement, will remain unchanged. OWASA's water demand forecasts also assume that the limited amount of land available for future growth and development under existing local policies will result in service area "buildout" sometime during the next SO years. At that time, the historic trend of increasing water demands would level off at a demand of between 16 and 22 MGD. We note that the demand forecasting methods prescribed for these draft applications do not provide for any variation from the forecast demand curves. OWASA's own analyses include "high" and "law" bands of uncertainty that vary approximately 10 percent above and below the "expected growth" line. Rate of Quarry Expansion and Ultimate Capacity -The ultimate yield of the extended Quarry Reservoir will depend on its water storage capacity. OWASA's sustainable yield projections are based on a final capacity of 3 billion gallons (BG). The current capacity of American Stone's active quarry is approximately 1 billion gallons. OWASA's existing Quarry Reservoir has a storage volume of 0.2 bg. American Stone's agreement with OWASA contains a "due diligence" commitment to maintain rock production at an average rate of 650,000 tons per year, which corresponds to a quarry pit volume increase of 0.065 billion gallons per year. At this rate, quarry volume will increase by 1.95 bg over the next 30 years, providing a total volume of slightly more than 3 BG. If -due tp economic conditions, market competition, or changes in corporate policy -- American Stone's production activity decreased below this level, or if the company went out of business and stopped production altogether, then the usable storage volume and resulting water supply yield would be less than what has been projected.