New Waves July 2009

Breaking news about water resources research and education in Texas

New Publications/Papers and Training Courses

New Publications/ Papers

Evaluation of Canal Lining Projects in the Lower Rio Grande Valley, A. Karimov, E. Leigh, G. Fipps, Texas Water Resources Institute Report TR-353, 2009

Since 1999, seven irrigation districts in the Lower Rio Grande Valley of Texas have installed six different types of synthetic canal lining materials, totaling approximately 21 miles. In 2005, we began a program to track the long term effectiveness and durability of these lining projects and to document the damage caused by such factors as UV, animal traffic, intentional and unintentional vandalism, and normal irrigation district operational and maintenance activities. Each project was evaluated using a visual inspection process during which performance/condition ratings were assigned. Without question, the best lining system is a synthetic liner with a protective barrier of shotcrete. The synthetic liner significantly reduces seepage, while the shotcrete protects it from damage. This lining system needs little to no maintenance. There were two types of liners used: PVC and polyester. Each performed equally as well. Additional details are provided in this report, along with suggested considerations when planning a lining project. A summary of the findings for each individual lining project is presented in the Appendix B of this report which is published separately.

Evaluation of Smart Irrigation Controllers: Initial Bench Testing Results, C. Swanson, G. Fipps, Texas Water Resources Institute Report TR-354, 2009

A smart controller testing facility has been established by the Irrigation Technology Center at Texas A&M University in College Station. Six manufacturers donated controllers for initial laboratory set-up and evaluation. For evaluation purposes, the controllers were programmed for College Station, Texas using the virtual landscape as defined in the IA (Irrigation Association) SWAT (Smart Water Applicator Technologies) 7th draft testing protocol. However, the controllers could not be programmed with all the parameters required to define these virtual landscapes. The controllers were then run over an eight-week period. The results are compared to the actual ETo during the test periods and to the irrigation recommendations of the TexasET Network. The irrigation amounts produced by the controllers varied significantly, even for the same zone. In addition, all exceeded the irrigation recommendations of TexasET. Four of the controllers produced irrigation amounts that were higher than the ETo (potential evapotranspiration) that occurred during the test period. Such high irrigation amounts may be related to the source and values for the ETo used by the controllers and/or in the methodologies used to account for rainfall. The results will be used to establish protocols for further testing.

TWRI Water Resources Training Courses

5th Annual SWAT Conference & Workshops Aug. 3-7, 2009
Texas Watershed Planning Short Course Aug. 17-21, 2009
Getting in Step (Houston) Sept. 22, 2009
Getting in Step (Austin) Sept. 23, 2009
Getting in Step (Dallas) Sept. 24, 2009

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