Submitted to: Irrigation and Water Quality Research Reports
Publication Type: Other
Publication Acceptance Date: 11/1/2004
Publication Date: 11/15/2004
Citation: Marek, T., Amosson, S., Muttiah, R., Almas, L., New, L., Howell, T.A., Bretz, F., Guerro, B., Simpson, N. 2004. Development of an agricultural water use estimating methodology. Prepared for Texas Water Development Board by Texas Agricultural Experiment Station and Texas Cooperative Extension in cooperation with U.S. Department of Agriculture, Agricultural Research Service. Interpretive Summary: Water planning for future needs requires accurate determination of the water used in various applications and industries. Irrigated agriculture is one of the largest water consumers in Texas and, its water use is difficult to estimate. This is a project report for the Texas Water Development Board to guide their choices in providing advice to the various regional water planning groups empowered to conduct regional water planning to meet future water needs in their region of the State. It considered various water consumption procedures including satellite imagery and remote sensing and various crop simulation models. The project team selected a procedure that uses weather stations to estimate the crop water use and local on-farm data from extension demonstrations to predict the water used by each crop in a county. The costs to create the data needed and the costs to operate the procedures were estimated. The procedures should provide scientifically based estimates that are accurate for the least cost to the State.
Technical Abstract: Future water need projections depend on developing accurate planning and assessment tools to determine available water resources and the consumption of those water resources. Irrigated agriculture is one of the largest consumers of fresh water in Texas. This project was directed to identify and recommend scientifically based methodologies that could be used in Texas to improve the estimation of irrigation water requirements and water use in agriculture and to identify the data resources and most appropriate methodology for estimating this water use. An evapotranspiration (ET) based methodology was recommended and crop modeling and remote sensing methods were evaluated and considered and reviewed. The proposed methods utilize existing weather station networks and existing on-farm demonstration data to determine gross water use. The report summarized the capital and startup training costs necessary to implement the various methodologies.