ASSESSING THE LOWER KENTUCKY RIVER PUBLIC WATER SUPPLY IN 2050: WHEN AN UNDERGRADUATE CLASS PROJECT RETURNS REAL INFORMATION

The lower Kentucky River (LKR) is the public water supply source for about 683,000 people residing in 15 counties in central Kentucky, 92% of the population in 2010. The public water supply in these counties was about 107x10⁶ gal/day in 2010, or about 2.3% of the average LKR flow of 4713x10⁶ gal/day. As yet, however, there are no public reports assessing the future public water supply for the rapidly growing populations in these counties, although the existing public water supply infrastructure is expected to be adequate through 2030. As a class term project, students in an undergraduate quantitative reasoning course in the Department of Earth and Environmental Sciences at the University of Kentucky were asked to model the LKR public water supply in 2050. Their model considered the total water supply in the LKR, population demographics and public water supply demand, and precipitation as affected by climate change. Data and information were gleaned from municipal, State, and Federal sources, including regulatory agency filings and climate models from the literature. These data were compiled into a unified database, and a water supply forecast was developed. Population and demand in the LKR counties is forecast to increase 52% by 2050, with 98% of the population assumed to be using the public water supply by then. At an average historical per capita demand of 142 gal/day, the public water supply required by this population will be 157x10⁶ gal/day. Climate model forecasts from the literature show a 5% increase in precipitation in central Kentucky by 2050, all of which was assumed as contributing runoff to the Kentucky River flow. Total forecast LKR water supply is 7070x10⁶ gal/day in 2050, thus the public water supply demand is estimated to be 2.2% of the available supply, or comparable to the current demand. The conclusions of this project are that the volume of water available in the LKR will be adequate for public water supply demand, but the water supply infrastructure available in 2050 would be more likely to affect the deliverable supply.