This study, by UTSA's Center for Community and Business Research at the Institute for Economic Development, was done at the request of the San Antonio River Authority, for the use of water planning groups in South Central Texas Region L counties. With the aid of experts, peer review literature, government websites and database, the staff at the CCBR has collected, analyzed and summarized data findings pertaining to population projections for the Region L counties: Atascosa, Bexar, Caldwell, Calhoun, Comal, DeWitt, Dimmit, Frio, Goliad, Gonzales, Guadalupe, Hays (southern half), Karnes, Kendall, La Salle, Medina, Refugio, Uvalde, Victoria, Wilson and Zavala. With the need for water user groups to use population projections for several decades from the present, as well as the unexpected influx of thousands of people in relation to Eagle Ford Shale activity, representatives of Region L contracted with the CCBR for an objective study concerning population projections for the area. The Texas Water Development Board allows for a review of population projection data, with criteria for adjustment that includes documentation of the need for a census recount, significant rate difference, or substantial rate difference in population change. This study has compared results and findings with the standard population projection data offered by the Texas State Data Center, prepared by the Office of the State Demographer, which lists three scenarios for fertility, mortality and migration: normal (0), conservative (.5) and aggressive (1). Results show that there is indeed evidence for many counties to request a recount from the United States Census Bureau, as well as evidence of significant and substantial rate change differences in population change that can result in population projection numbers that are different from those currently published by the State. As the State is aware of the economic activity and associated population movements into the Region L area, the Office of the State Demographer has been updating available data and analysis. With this in mind, this study also includes information for understanding some of the methodology for population projections, discussion of how to read the outputs and make judgments on which data best reflects the situations the Region L counties face and background about the economic circumstances these communities face in relation to the Eagle Ford Shale. This research team hopes that the principles in this study will serve not only the current need for planning documentation, but also as a guide for future planning and analysis by those who need an understanding of how to navigate population projection materials and associated data.