Technical and Special Reports
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Item Bacteria Runoff BMPs for Intensive Beef Cattle Operations(Texas Water Resources Institute, 2010-12) Wagner, Kevin; Redmon, Larry; Gentry, TerryAccording to the 2008 Water Quality Inventory and 303(d) List, 291 of the 516 impairments (i.e. 56%) were the result of excessive bacteria. Modeling and bacteria source tracking has identified grazing cattle as a source of this bacterial contamination. To help address this, the Natural Resources Conservation Service (NRCS) funded this project to evaluate the effect of stocking rate on pathogen transport from beef cattle operations and develop guidance for landowners on restoring water quality. The project included three tasks: (1) Project Coordination and Administration, (2) Assess Bacteria Runoff from Intensively Managed Beef Cattle Operations, and (3) Technical Transfer. Task 1, Project Coordination and Administration, consisted of the Texas Water Resources Institute (TWRI) preparing and submitting eleven quarterly progress reports and the final project report, holding 25 coordination meetings, and submitting 12 invoices. To evaluate the impact of grazing management on bacterial runoff (Task 2), TWRI and Texas AgriLife Extension Service (AgriLife Extension) installed three 1-hectare watershed sites at the Texas A&M University Beef Cattle Systems Center (BCSC), located near College Station. Sites were bermed and equipped with 90o v-notch weirs, ISCO® samplers with bubble flow meters, and a rain gage. TWRI and AgriLife Extension maintained these watershed sites for two years, conducting over 30 site visits. A variety of stocking rates were evaluated. Site BB1 was ungrazed. Site BB2 was stocked at typical stocking rates (SR) for the area (i.e., 3-4 acres per animal unit [AU]). Site BB3 was stocked at a rate twice that of site BB2. Over the course of the project, six grazing treatments were conducted at sites BB2 and BB3. From November 2008 through October 2010, TWRI and AgriLife Extension assessed bacterial concentrations and runoff volume from the watershed sites. E. coli concentrations at all sites greatly exceeded Texas Water Quality Standards. Even at the ungrazed site, non-domesticated animals (i.e., feral hogs) and wildlife significantly impacted E. coli levels preventing attainment of water quality standards, thus indicating the difficulty in achieving standards during runoff events due to background loadings. Data also indicated moderate stocking does not significantly increase E. coli levels above background levels and suggests that 67-85% reductions in E. coli levels may be achieved by converting from heavy to moderate stocking rates. It was also found that pastures stocked heavier than 10 acres per AU should be the primary focus of implementation efforts in this and similar environments. Our data indicated (1) stocking at rates heavier than 10 acres per AU (as is much of the improved pastureland in Texas) may increase E. coli concentrations in runoff while (2) stocking at rates less than 10 acres per AU (much of the rangeland in Texas) does not yield higher E. coli levels than ungrazed pastures. Finally, data show that runoff events occurring while the sites were stocked or within two weeks of them being stocked produced the highest E. coli concentrations; thus, it is recommended grazing in creek pastures be deferred during rainy periods. Within two weeks of grazing, E. coli levels had fallen substantially and after 30 days, E. coli values had declined to background levels. The findings and recommendations regarding appropriate stocking rates/grazing management to minimize bacterial runoff into surface waters of Texas are being included in a fact sheet, presentation, and other resources that will become part of the Lone Star Healthy Streams Beef Cattle Resource Manual. Throughout this project a series of educational programs conducted through the Lone Star Healthy Streams Program transferred information regarding bacterial runoff and conservation practices for reducing it to livestock producers at over 60 programs around the state. Additionally, the website reached 1,038 unique visitors since its inception. These programs have increased awareness of bacterial runoff from beef cattle grazing operations and conservation practices designed to reduce bacterial loading to Texas streams and water ways. Much work remains to be done. The applicability of water quality standards during runoff events should be evaluated in light of the findings of this study; more data is needed to evaluate the impact of stocked pastures on bacterial runoff; work is needed to assess the impacts of continuous grazing on E. coli runoff; and transfer of this information to cattlemen throughout Texas must continue.Item Energy Use and Irrigation Scheduling for Efficient Water Use(Texas Water Resources Institute, 2010-09) Marek, Thomas; Porter, DanaTexas High Plains Evapotranspiration (TXHPET) network personnel continued to operate and maintain the network of 15 to 18 weather stations to provide timely weather and evapotranspiration (ET) data in support of related research and extension projects. This network provided computational and dissemination services including a listserv email program to supply data to researchers on a daily basis. Approximately 1.7 million pages of ET and meteorological data were distributed by the TXHPET system over the duration of this agreement. The data were utilized in 21 refereed journal articles and 156 other publications and presentations, as well as in numerous other publications by other (non-related CRIS projects based at USDA-ARS Lubbock, Texas A&M University, West Texas A&M University, Texas Tech University, Texas AgriLife Research and Texas AgriLife Extension Service). The project also developed a research design for infrastructure expansion of the reference ET facility at Bushland for advanced aerodynamic studies. In addition, a new web based user profile using the TXHPET network data is under development to provide more integrated tools and greater benefit to users.Item Lake Granbury and Lake Whitney Assessment Initiative(Texas Water Resources Institute, 2010-10) Harris, B.L.; Roelke, Daniel; Grover, James; Brooks, BryanA team of Texas AgriLife Research, Baylor University and University of Texas at Arlington researchers studied the biology and ecology of Prymnesium parvum (golden algae) in Texas lakes using a three-fold approach that involved system-wide monitoring, experimentation at the microcosm and mesocosm scales, and mathematical modeling. The following are conclusions, to date, regarding this organism’s ecology and potential strategies for mitigation of blooms by this organism.Item Provide Assistance to Improve Water Quality in Hood County(Texas Water Resources Institute, 2010-09) Lesikar, Bruce; Mechell, Justin; Clayton, Brent; Gerlich, RyanThe overall goal for this project was to provide a mechanism to educate local stakeholders about water quality issues that affect Lake Granbury. This project provided an assessment of existing and potential water quality threats related to on-going non-point source (NPS) water pollution within the Lake Granbury Watershed. The Texas Water Resources Institute (TWRI) and Texas AgriLife Extension Service are assisting Brazos River Authority (BRA) and Texas Commission on Environmental Quality (TCEQ) to develop a Watershed Protection Plan (WPP) aimed to improve and protect water quality within the Brazos River Basin. Educational information developed during this project provided Federal, State and local decision makers with a variety of mechanisms that can be employed to prevent additional degradation of water quality in the watershed.Item Texas Watershed Planning Short Course Final Report(Texas Water Resources Institute, 2010-08) Wagner, KevinProper training of watershed coordinators and water professionals is needed to ensure that watershed protection efforts are adequately planned, coordinated and implemented. To provide this training, the Texas Watershed Planning Short Course was developed through a coordinated effort led by the Texas Water Resources Institute and funded by the U.S. Environmental Protection Agency through the Texas Commission on Environmental Quality. The Texas Water Resources Institute partnered with the Texas AgriLife Extension Service, Texas AgriLife Research, Texas State Soil and Water Conservation Board, Texas Commission on Environmental Quality, U.S. Environmental Protection Agency, Texas State University-River Systems Institute and the Texas Institute for Applied Environmental Research to develop and conduct this short course. Since 2008, four week-long Watershed Planning Short Courses have been hosted, providing training to over 160 watershed professionals on sustainable proactive approaches to managing water quality throughout the state. The Watershed Planning Short Course provides guidance on stakeholder coordination, education, and outreach; meeting the U.S. Environmental Protection Agency’s nine key elements of a watershed protection plan; data collection and analysis; and the tools available for plan development. Along with the Watershed Planning Short Courses, water professionals were invited to attend Texas Watershed Coordinator Roundtables, held biannually, to (1) provide a forum for establishing and maintaining dialogue between watershed coordinators, (2) facilitate interactive solutions to common watershed issues faced throughout the state, and (3) add to the fundamental knowledge conveyed at the short courses. More than 250 water professionals attended the four Texas Watershed Coordinator Roundtables held in Temple, Georgetown and Dallas. Topics of discussion included sustainable organizational structure for long-term watershed protection plan implementation; the U.S. Environmental Protection Agency’s Region 6 review guide of watershed-based plans; strategies and expectations for demonstrating successful implementation and financing watershed protection plans. Additional workshops also offered to further familiarize watershed coordinators with watershed management tools provided by the U.S. Environmental Protection Agency included Getting In Step Workshops and Key EPA Internet Tools for Watershed Management courses. The Getting In Step Workshop aims to improve the effectiveness of nonpoint source outreach in Texas and the internet tools course familiarizes users with online watershed management tools provided by the U.S. Environmental Protection Agency. More than 90 watershed professionals participated in four Getting In Step Workshops offered in Houston, Austin, Dallas and Georgetown. Nearly 40 watershed professionals participated in the two Key EPA Internet Tools for Watershed Management courses offered in San Marcos and Dallas. Also, the Texas Water Resources Institute coordinated with Wildland Hydrology to provide an Applied Fluvial Geomorphology Short Course with 40 water resource professionals participating to better understand the fundamentals and general principles of river behavior. To assist watershed professionals in searching for funding programs, the Texas Water Resources Institute worked with the Environmental Finance Center at Boise State University to update the Directory of Watershed Resources to include Texas-specific funding programs. The Environmental Finance Center Network is an EPA-sponsored, university-based program providing financial outreach services. The Directory of Watershed Resources is an on-line, searchable database for watershed restoration funding. The database includes information on federal, state, private, and other funding sources and assistance and allows Texas users to query information in a variety of ways including by agency sponsor or keyword, or by a detailed search. In total, the combined courses, workshops and meetings have reached out to more than 350 watershed coordinators and water professionals and will continue to do so by hosting biannual Watershed Coordinator Roundtable meetings and training opportunities.Item Supplement to Diagnosis and Management of Salinity Problems in Irrigated Pecan Production: Salt Leaching(Texas Water Resources Institute, 2010-07) Miyamoto, S.In the publication prepared in 2006 with the above title (TWRI. TR-287), we described ways to diagnose salt problems which affect irrigated production of pecans. We also discussed the concepts of minimizing soil salinization, and ways to lower soil salinity. However, the materials presented were general and introductory in nature. This article is to supplement the previous publication with technical details, and practices of salt leaching during the routine irrigation as well as salt leaching irrigation for restoration. The aim of salt leaching is to keep soil salinity of the root zone below the level that trees can tolerate. The threshold salinity of irrigated pecans is in the range of 2 to 3 dS m-1 when measured in the soil saturation extract (Fig. 1), which is an official method of measuring soil salinity (Miyamoto et al., 1986). In the areas rich in gypsum, trees may tolerate higher levels of soil salinity, probably by 1 or 2 dS m-1. Calcium and sulfate ions are less harmful to pecan trees than sodium and chloride ions (Miyamoto et al., 1985). There are basically two ways to approach the task of salt leaching. The first approach is to maintain leaching following each irrigation so as to keep soil salinity in check. The first half of this article is devoted for describing ways to minimize soil salinization through this approach. The second approach is to let salts accumulate in portions of the orchards, then to flush salts out during the dormant period. This approach takes the reality into account; soil salinity levels vary widely even in a small orchard, and that it is more convenient to carry out leaching during the dormant period. Once a part of the orchard begins to be salinized, (meaning that soil salinity exceeds the threshold salinity level), growers need to carry out salt leaching irrigation for restoration. When dealing with restoration, the causes of salinization have to be identified prior to deciding the methods of salt leaching. This Fig. 1 Trunk cross-section as affected by salinity or Na concentrations in the soil saturation extract (Miyamoto, 1986). subject is discussed in the second part of this article.Item Economies of Size in Municipal Water-Treatment Technologies: A Texas Lower Rio Grande Valley Case Study(Texas Water Resources Institute, 2010-07) Boyer, Christopher N.; Rister, M. Edward; Rogers, Callie S.; Sturdivant, Allen W.; Lacewell, Ronald D.; Browning, Charles Jr.; Elium III, James R.; Seawright, Emily K.As the U.S. population continues to increase, the priority on planning for future water quantity and quality becomes more important. Historically, many municipalities have primarily relied upon surface water as their major source of drinking water. In recent years, however, technological advancements have improved the economic viability of reverse-osmosis (RO) desalination of brackish-groundwater as a potable water source. By including brackishgroundwater, there may be an alternative water source that provides municipalities an opportunity to hedge against droughts, political shortfalls, and protection from potential surfacewater contamination. In addition to selecting a water-treatment technology, municipalities and their associated water planners must determine the appropriate facility size, location, etc. To assist in these issues, this research investigates and reports on economies of size for both conventional surface-water treatment and brackish-groundwater desalination by using results from four water-treatment facilities in the Texas Lower Rio Grande Valley (LRGV). The methodology and associated results herein may have direct implications on future water planning as highlighting the most economically-efficient alternative(s) is a key objective. In this study, economic and financial life-cycle costs are calculated for a “small” conventional surface-water facility (i.e., 2.0 million gallons per day (mgd) Olmito facility) and a “small” brackish-groundwater desalination facility (i.e., 1.13 mgd La Sara facility). Thereafter, these results are merged with other, prior life-cycle cost analyses’ results for a “medium” conventional surface-water facility (i.e., 8.25 mgd McAllen Northwest facility) and a “medium” brackish-groundwater desalination facility (i.e., 7.5 mgd Southmost facility). The combined data allow for examination of any apparent economies of size amongst the conventional surface-water facilities and the brackish-groundwater desalination facilities. This research utilized the CITY H20 ECONOMICS and the DESAL ECONOMICS © © Excel® spreadsheet models developed by agricultural economists with Texas AgriLife Research and Texas AgriLife Extension Service. The life-cycle costs calculated within these spreadsheet models provide input for work which subsequently provides the estimations of economies of size. Although the economies of size results are only based on four facilities and are only applicable to the Texas LRGV, the results are nonetheless useful. In short, it is determined that economies of size are apparent in conventional surface-water treatment and constant economies of size are apparent in brackish-groundwater desalination. Further, based on modified life-cycle costs (which seek to more-precisely compare across water-treatment technologies and/or facilities), this research also concludes that reverse-osmosis (RO) desalination of brackish-groundwater is economically competitive with conventional surface-water treatment in this region.Item Assembly and Testing of an On-Farm Manure to Energy Conversion BMP for Animal Waste Pollution Control(Texas Water Resources Institute, 2010-06) Engler, Cady; Capereda, Sergio; Mukhtar, SaqibNumerous gasification experiments were conducted and proved that with proper moisture content (usually near 10%) animal manure can be gasified using the TAMU fluidized bed gasifier. In summary the following has been established. • The heating value of dairy manure on a dry basis was found to be 15.93 + 0.26 MJ/kg (6,863 + 112 Btu/lb), typical of most agricultural biomass. The heating value was around 14.09 MJ/kg (6,070 Btu/lb), on an “as received” basis (around 13% moisture). • The heating value of synthesis gas from gasification of animal manure was estimated to be around 4.2 MJ/m3 (113 Btu/ft3). This value is very similar to most synthesis gas from agricultural residues. • Synthesis gas production per unit weight of manure was estimated to be 2.11 m3/kg. The gas production energy efficiency was estimated to be around 55.6% (i.e. 55.6% of the energy was contained in the synthesis gas). • Char production was on the average around 20% of the feed input. The average heating value of manure char was around 19 MJ/kg (8,816 Btu/lb). Thus, the char energy conversion efficiency was approximately 24% (i.e. 24% of the energy was still contained in the char). • Twenty percent (20%) of the energy from the biomass was used during the gasification to maintain the temperature of the reactor. Gasification is a continuous, endothermic process and thus, no external fuel is needed other than that used during startup. Natural gas was used during start-up and would last around 30 minutes. After the initial heating of the reactor, part of the biomass materials were used to maintain the operating temperature and the natural gas fuel source was shut off. • The chemical formula for dairy manure during combustion is shown below. This formula was used only for stoichiometric calculation purposes only. • Eutectic point analysis of the manure ash showed that the inorganic ash components will start to melt at around 600°C (1112°F). This was established using compressive strength as an indicator of fusion reactions. • When used for power generation, it was expected to generate at least 25 kW of electrical power output for a 30 cm diameter pilot facility (i.e. at 1.6 tonnes/day (1.8 tons/day)) of feed input. The assumed conversion efficiency was roughly 15% (from synthesis gas to electrical power in a natural gas-type engine-generator).Item Initial Evaluation of Smart Irrigation Controllers: Year Two (2009) Results(Texas Water Resources Institute, 2010-04) Swanson, Charles; Fipps, GuyA smart controller testing facility was established by the Irrigation Technology Center at Texas A&M University in College Station in 2008. A two-year testing program was initiated in order to evaluate smart controller testing methodology needed to determine their performance and reliability under Texas conditions from an “end-user” point of view. The “end-user” is considered to be the landscape or irrigation professional (such as a Licensed Irrigator in Texas) installing the controller. During the first year (2008), six (6) controllers were evaluated over a 60- day period. Details were provided by Swanson and Fipps (2008). This report details the results of the second year (2009) evaluations. Four additional controllers were provided by manufacturers for the 2009 evaluations, bringing the total number of controllers evaluated to 10, and the evaluation period was extended to 13 weeks. As in the first year, the 10 controllers were programed for College Station, Texas using a modified version of the virtual landscape as defined in the IA (Irrigation Association) SWAT (Smart Water Applicator Technologies) 7th draft testing protocol. Programing the controllers according to these virtual landscapes proved to be problematical, as most of the controllers did not allow the direct programing of all of the parameters needed to define the virtual landscape and irrigation system. In addition, it was impossible to see the actual values that some controllers used for each parameter or to determine how closely these followed the values of the virtual landscape. The 2009 results showed some improvement in controller performance over Year One results. There were no software or hardware problems observed. Only one controller had communication problems which were reported to the manufacturer’s representative but not corrected during the study.Item Irrigation Training Program For Texas Agricultural Producers(Texas Water Resources Institute, 2010-02) Harris, B.L.The Irrigation Training Program, funded by the Texas Water Development Board (TWDB) through an Agricultural Water Conservation Grant, began in 2006. Administered by the Texas Water Resources Institute (TWRI), the Texas State Soil and Water Conservation Board (TSSWCB), the local Soil and Water Conservation Districts (SWCDs), United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS), Texas AgriLife Extension Service (Extension) and Texas AgriLife Research (Research) worked together to build a multi-disciplinary Irrigation Training Program (ITP) that included development of a core manual and training conferences that were designed to meet regional needs. The three year project was divided into four main tasks with separate objectives and deliverables. Under Task 1, the TSSWCB, SWCDs and USDA-NRCS supported the development and implementation of the Irrigation Training Program. Task 2 required TWRI, Extension and Research, in cooperation with the TSSWCB and USDA-NRCS to identify primary agency personnel to provide training and the key conference sites. To meet the objective of Task 3, TWRI, Extension and Research, in cooperation with the TSSWCB and USDA-NRCS developed the Irrigation Training Program manual and promoted irrigation training conferences. And finally, TWRI, Extension and Research, in cooperation with the TSSWCB and USDA-NRCS implemented the Irrigation Training Program through the delivery of six irrigation conferences to meet the task 4 goals.Item The Development of a Coordinated Database for Water Resources and Flow Model in the Paso Del Norte Watershed (Phase III) Part III GIS Coverage for the Valle de Juárez Irrigation District 009 (ID-009) (Distrito de Riego 009) Chihuahua, México(Texas Water Resources Institute, 2009) Sheng, Zhuping; King, J. Phillip; Creel, Bobby; Brown, Christopher; Michelsen, Ari; Srinivasan, RaghavanThis report fulfills the deliverables required by the cooperative agreement between the U.S. Army Corps of Engineers and Texas Agricultural Experiment Station (TAES/03-PL- 02: Modification No. 3) on behalf of the Paso del Norte Watershed Council. Tasks accomplished in this phase include (a) assessment of data availability for expansion of the URGWOM model, identification of data gaps, generation of data needed from historic data using empirical methods, compilation and verification of the water quality data for reaches between the Elephant Butte Reservoir, New Mexico and Fort Quitman, Texas; (b) development of the RiverWare physical model for the Rio Grande flow for the selected reaches between Elephant Butte Reservoir and El Paso, beginning with a conceptual model for interaction of surface water and groundwater in the Rincon and Mesilla valleys, and within the limits of available data; and (c) implementation of data transfer interface between the coordinated database and hydrologic models. This Project was conducted by researchers at Texas A&M University (TAMU) and New Mexico State University (NMSU) under the direction of Zhuping Sheng of TAMU and J. Phillip King of New Mexico State University. It was developed to enhance the coordinated database, which was originally developed by the Paso del Norte Watershed Council with support of El Paso Water Utilities to fulfill needs for better management of regional water resources and to expand the Upper Rio Grande Water Operations Model (URGWOM) to cover the river reaches between Elephant Butte Dam, New Mexico and Fort Quitman, Texas. In Phases I and II of this Project (TAES/03-PL-02), hydrological data needed for flow model development were compiled and data gaps were identified and a conceptual model developed. The objectives of this phase were to develop a physical model of the Rio Grande flow between Elephant Butte Dam and American Dam by using data collected in the first development phase of the PdNWC/Corps Coordinated Water Resources Database and to enhance the data portal capabilities of the PdNWC Coordinated Database Project. This report is Part III of a three part completion report for Phase III and provides information on water sources, uses, and GIS of the canals and ditches of the Valle de Juárez Irrigation District 009 (ID 009) in the Juárez Lower Valley, Chihuahua, México. The author explains that the water needs of this region have changed in recent years from being primarily for agricultural purposes to domestic and industrial uses currently. Also, the United States wanted to assess and identify new data sources on a GIS format for the Mexican side. Therefore, this project produced several maps with the location of channels and ditches along the Valle de Juárez Irrigation District. This information also will support water planning of the Valle de Juárez Irrigation District 009. The maps were produced from existing digital data regarding water resources and by adding thematic layers such as soil salinity and soil texture from analog maps. ASTER satellite imagery and official panchromatic aerial photography were used to produce the maps.Item The Development of a Coordinated Database for Water Resources and Flow Model in the Paso Del Norte Watershed (Phase III) Part II Availability of Flow and Water Quality Data for the Rio Grande Project Area(Texas Water Resources Institute, 2009) Tillery, Sue; Sheng, Zhuping; King, J. Phillip; Creel, Bobby; Brown, Christopher; Michelsen, Ari; Srinivasan, Raghavan; Granados, AlfredoThis report fulfills the deliverables required by the cooperative agreement between the U.S. Army Corps of Engineers and Texas AgriLife Research (TAES/03-PL-02: Modification No. 3) on behalf of the Paso del Norte Watershed Council. Tasks accomplished in this phase include (a) assess the data availability for expansion of the URGWOM model, identify data gaps, generate data needed from historic data using empirical methods, compile and verify the water quality data for reaches between the Elephant Butte reservoir, New Mexico and Fort Quitman, Texas; (b) develop the RiverWare physical model for the Rio Grande flow for the selected reaches between Elephant Butte Reservoir and El Paso, beginning with a conceptual model for interaction of surface water and groundwater in the Rincon and Mesilla valleys, and within the limits of available data; (c) implement data transfer interface between the coordinated database and hydrologic models. This Project was conducted by researchers at Texas A&M University (TAMU) and New Mexico State University (NMSU) under the direction of Zhuping Sheng of TAMU and J. Phillip King of New Mexico State University. It was developed to enhance the coordinated database, which was originally developed by the Paso del Norte Watershed Council with support of El Paso Water Utilities to fulfill needs for better management of regional water resources and to expand the Upper Rio Grande Water Operations Model (URGWOM) to cover the river reaches between Elephant Butte Dam, New Mexico and Fort Quitman, Texas. In Phases I and II of this Project (TAES/03-PL-02), hydrological data needed for flow model development were compiled and data gaps were identified and conceptual model was developed. The objectives of this phase were to develop a physical model of the Rio Grande flow between Elephant Butte Dam and American Dam by using data collected in the first development phase of the PdNWC/Corps Coordinated Water Resources Database and to enhance the data portal capabilities of the PdNWC Coordinated Database Project. This report is Part II of a three part completion report that combines data compilation of the Phase I report prepared by Sue Tillery and J. Phillip King and part of the completion report for Phase III prepared by Z. Sheng, J.P. King and B. Creel. It identifies and evaluates the availability of historical flow and water quality data that has been collected at different sites along the Rio Grande between Elephant Butte Dam, New Mexico and Fort Quitman, Texas. This includes monitoring sites from associated canals, drains, and dams along the Rio Grande. Flow data for the years from 1908 through 2002 and water quality data for the years 1938 to 2005 collected periodically by different agencies include historic chemical analytical results and real-time monitoring values. This report includes a description of the agencies that collected water quality data, a summary of the sites found along the Rio Grande, and finally a data matrix and parameter summary for each site. Data downloaded were collected from the U.S. International Boundary and Water Commission (USIBWC), El Paso, Texas; US Geological Survey (USGS), U.S. Bureau of Reclamation, Elephant Butte Irrigation District (EBID), El Paso County Water Improvement District No. 1, and Parsons Engineering Science, Inc. compiled for the New Mexico-Texas Water Commission by contract through El Paso Water Utilities.Item The Development of a Coordinated Database for Water Resources and Flow Model in the Paso Del Norte Watershed (Phase III) Part I Lower Rio Grande Flood Control Model [LRGFCM] RiverWare Model Development(Texas Water Resources Institute, 2009) Tillery, Sue; Sheng, Zhuping; King, J. Phillip; Creel, Bobby; Brown, Christopher; Michelsen, Ari; Srinivasan, Raghavan; Granados, AlfredoThis report fulfills the deliverables required by the cooperative agreement between the U.S. Army Corps of Engineers and Texas AgriLife Research (TAES/03-PL-02: Modification No. 3) on behalf of the Paso del Norte Watershed Council. Tasks accomplished in this phase include (a) assess the data availability for expansion of the URGWOM model, identify data gaps, generate data needed from historic data using empirical methods, compile and verify the water quality data for reaches between the Elephant Butte Reservoir, New Mexico and Fort Quitman, Texas; (b) develop the RiverWareTM physical model for the Rio Grande flow for the selected reaches between Elephant Butte Reservoir and El Paso, beginning with a conceptual model for interaction of surface water and groundwater in the Rincon and Mesilla valleys, and within the limits of available data; (c) implement data transfer interface between the coordinated database and hydrologic models. This Project was conducted by researchers at Texas A&M University (TAMU) and New Mexico State University (NMSU) under the direction of Zhuping Sheng of TAMU and J. Phillip King of New Mexico State University. It was developed to enhance the coordinated database, which was originally developed by the Paso del Norte Watershed Council with support of El Paso Water Utilities to fulfill needs for better management of regional water resources and to expand the Upper Rio Grande Water Operations Model (URGWOM) to cover the river reaches between Elephant Butte Dam, New Mexico, and Fort Quitman, Texas. In Phases I and II of this Project (TAES/03-PL-02), hydrological data needed for flow model development were compiled and data gaps were identified and conceptual model development. The objectives of this phase were to develop a physical model of the Rio Grande flow between Elephant Butte Dam and American Dam by using data collected in the first development phase of the PdNWC/Corps Coordinated Water Resources Database and to enhance the data portal capabilities of the PdNWC Coordinated Database Project. This report is Part I of a three part completion report for Phase III and describes the development of RiverWare model of Rio Grande flows and a coordinated database for water related resources in the Rio Grande watershed. The RiverWare physical model for Rio Grande flows included selected reaches between Elephant Butte Reservoir and El Paso using historical data from 1985 to 1999. A conceptual model for interaction of surface and groundwater was developed using an ARIMA time-series transfer function analysis. ARIMA transfer functions are used as a means to estimate the interactions of surface and groundwater. Forecasting drain flows from diversion flows is demonstrated as a statistically valid method, and provides results highly correlated with the historic values.Item Education Program for Improved Water Quality in Copano Bay Task Two Report(Texas Water Resources Institute, 2009) Wagner, Kevin; Moench, EmilyThe Education Program for Improved Water Quality in Copano Bay is funded through a Clean Water Act §319(h) Nonpoint Source Grant from the Texas State Soil and Water Conservation Board (TSSWCB) and the U.S. Environmental Protection Agency (TSSWCB Project 06-08). The goal of the project is to improve water quality in Copano Bay and its tributaries by increasing awareness of the water quality issues throughout the watershed and providing education and demonstrations for land and livestock owners on methods to decrease or prevent bacteria from entering the waterways.Item A Simple Model for Estimating Water Balance and Salinity of Reservoirs and Outflow(Texas Water Resources Institute, 2010-08-23T19:58:42Z) Miyamoto, S; Yuan, F; Anand, ShilpaReservoir storage reduces fluctuation in streamflow salinity, yet increases outflow salinity because of water evaporation. These processes are highly relevant to developing water management strategy, yet the method to predict outflow salinity has not been adequately examined. The study reported here examined the water and salt balance in a reservoir using a two-layer model. This model assumes that inflow blends with the storage, but the water evaporation takes place from the surface layer, and the percolation losses from the subsurface. The thickness of the first layer where salinity increases with evaporation was estimated through calibration against the measured outflow salinity. The changes in salinity were computed using a moving average method on a monthly time step. This model was applied first to Red Bluff Reservoir of the Middle Pecos River, then to Elephant Butte, Amistad, and Falcon along the Rio Grande. The outflow salinity projected by the model was in good agreement with the measured, except under a few circumstances where mixing of inflow and reservoir storage was suspected to be incomplete. The accuracy of prediction can be improved by improving the estimate of initial salinity of reservoir storage, which is currently taken as being equal to outflow salinity at the onset of the simulation.Item Evaluation of Irrigation Efficiency Strategies for Far West Texas: Feasibility, Water Savings And Cost Considerations(Texas Water Resources Institute, 2009-06)ABSTRACT Texas recently completed its second round of nationally recognized water planning. The Water Plan for the state addresses how each of 16 regions will supply projected water demands for the next 50 years. Water availability in these plans is based on supply conditions experienced during the drought of record, that is, the severe drought conditions in the 1950's. In arid Far West Texas, Region E in the State Plan, agriculture is projected to have the largest unmet demand for water during drought. This situation is similar to many other irrigated agricultural production regions in the U.S. and world that rely upon limited and variable water supplies. In the Far West Texas (Region E) 50-year Water Plan, the primary strategy proposed to mitigate the impact of insufficient water supplies for agriculture is implementation of water conservation best management practices. However, the conservation practices identified were generic and gave a wide range of potential water savings compiled from many other sources and for other locations and conditions. The feasibility and amount of water saved by any given conservation practice varies substantially across regions, specific location, type and quality of water supplies, delivery systems and operational considerations, crops produced, irrigation technologies in use, and location specific costs and returns of implementation. The applicability to and actual water savings of the proposed practices in Far West Texas were generally unknown. This report evaluates the applicability, water savings potential, implementation feasibility and cost effectiveness of seventeen irrigated agriculture water conservation practices in Far West Texas during both drought and full water supply conditions. Agricultural, hydrologic, engineering, economic, and institutional conditions are identified and examined for the three largest irrigated agricultural areas which account for over 90% of total irrigated agricultural acreage in Far West Texas. Factors considered in evaluating conservation strategies included water sources, use, water quality, cropping patterns, current irrigation practices, delivery systems, technological alternatives, market conditions and operational constraints. The overall conclusion is that very limited opportunities exist for significant additional water conservation in Far West Texas irrigated agriculture. The primary reasons can be summarized by: the most effective conservation practices have already been implemented and associated water savings realized throughout the region; reduced water quality and the physical nature of gravity flow delivery limit or prohibit implementation of higher efficiency pressurized irrigation systems; increased water use efficiency upstream has the net effect of reducing water supplies and production of downstream irrigators; and, water conservation implementation costs for a number of practices exceed the agricultural value and benefits of any water saved. Those practices that suggest economic efficient additional water conservation included lining or pipelining district canals and the very small potential for additional irrigation scheduling and tail water recovery systems. In nearly all cases, these practices have been adopted to a large extent if applicable, further emphasizing the very limited opportunities for additional conservation. If all of these strategies were implemented, the water conserved would satisfy less than 25% of the projected unmet agricultural water demand in 2060 during drought-of-record conditions Overall, there are no silver bullets for agricultural water conservation in Far West Texas short of taking irrigated land out of production when water supplies are limited.Item Economic Implications of Biological Control of Arundo donax in the Texas Rio Grande Basin(Texas Water Resources Institute, 2009-11) Seawright, Emily; Rister, M. Edward; Lacewell, Ronald; McCorkie, Dean; Sturdivant, Allen; Goolsby, John; Yang, Chenghai; Harris, B.L.ABSTRACT Arundo donax, or giant reed, is a large, bamboo-like plant that is native to Spain and has invaded several thousand acres of the Rio Grande riparian zone in Texas and Mexico. The plant grows to over 26 feet tall, and consumes large quantities of water, estimated as an amount equivalent to about 11% of irrigation water diverted by Valley irrigation districts (i.e., some estimates are more than 5.5 acre-feet per acre). With concern of increased water demands in the Texas Lower Rio Grande Valley region, the United States Department of Agriculture, Agricultural Research Service (USDA)ARS) is investigating four herbivorous insects as potential biological control agents for Arundo donax to facilitate increased water supply. This study examines selected economic implications for agricultural water users in the United States of applying these biological control agents along the Rio Grande. The research includes (a) estimating the value of the water saved due to the reduction of Arundo donax, (b) a benefit -cost analyses, (c) regional economic impact analyses, and (d) an estimate of the per-unit cost of water saved over a 50-year planning horizon (2009 through 2058). The model ArundoEcon© is used to perform a baseline deterministic analyses using low- and high-value irrigated composite acre values. That is, the saved water is initially valued based on being applied to agriculture as irrigation. Since the actual crop mix irrigated with the saved water is unknown, a range is provided by assuming all irrigated crops are “low-value,” and then again by including both “lowvalue” and “high-value” irrigated crops. Results of the water amount saved are 2/9 of the amount consumed, or approximately one acrefoot of water for each acre of Arundo. For each acre-foot of water saved, 1.85 dryland acres can be converted to low-value crop acres, and 0.71 can be converted to high-value crop acres. Regional economic results indicate a present value of farm-level benefits ranging from $98 to $160 million. Benefit-cost ratios are calculated with normalized prices and indicate a range from 4.38 to 8.81. Sensitivity analyses provide a robust set of results for Arundo agricultural water use, effectiveness of control agents, replacement species’ water use, Arundo expansion rate after control, value of water, and the cost of the program. The pre-production processes and farm-gate economic impact analyses are estimated using multipliers from the IMPLAN model. Regional results reveal a range of $9 to $18 million annually in economic output and 197 to 351 jobs associated with the increase in gross revenues due to the control of Arundo donax for the year 2025. Values for other select years are also provided. Further results suggest a life-cycle cost per acre-foot of water saved of $44. This amount is comparable to other projects designed to conserve water in the region. The USDA)ARS, Weslaco, Texas Arundo donax biological control project will realize positive results as indicated by the benefit-cost ratios, economic impact analyses, and competitive results for the per-unit cost of saving water. These results indicate this project will have positive economic implications for the U.S. and the Texas Lower Rio Grande Valley.Item 2009 International SWAT Conference Conference Proceedings(Texas Water Resources Institute, 2009-08)Item Economic and Financial Methodology for South Texas Irrigation Projects – RGIDECON©(2009-08) Rister, M. Edward; Rogers, Callie S.; Lacewell, Ronald; Robinson, John; Ellis, John; Sturdivant, AllenItem Education of Best Management Practices in the Arroyo Colorado Watershed(Texas Water Resources Institute, 2009-07)