Agricultural Water Consumption in the ACT/ACF River Basins: Approaches for Projecting Irrigated Acreage and Amounts

Proceedings of the 1999 Georgia Water Resources Conference, March 30 and 31, Athens, Georgia.Accurate assessment of current and future irrigation in the ACT/ACF river basins requires quantification of agricultural irrigation. Irrigated acreage is difficult to measure and project. No systematic monitoring of agricultural water application rates or irrigation volume occurs. Secondary sources must be combined with irrigation acreage estimates to derive irrigation water-use. Several sources and techniques available for determining irrigated acreage and water-use were compared. These approaches included surveys of farmers and experts, physical checks at random. locations, manual and computer analysis of remotely sensed images, crop models, and farmer-reported irrigation intentions. Four counties in Southwest Georgia with predominantly fixed irrigation systems were evaluated. There was good agreement among acres and irrigation volumes determined from surveys, physical checks, models, and image analysis. The four county total irrigation volume averaged 63.5 mgd for these approaches. The Comprehensive Basins Study and the DNR-EPD permitted irrigation volumes were higher than these four approaches by 65% and 160%, respectively. Where mobile irrigation systems are in use differences were greater. Each method has its flaws, gaps, and overlaps.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202 with partial funding provided by the U.S. Department of Interior, geological Survey, through the Georgia Water Research Insttitute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-397). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of the University of Georgia or the U.S. Geological Survey or the conference sponsors