http://handle.tamu.edu/1969.1/6061 Make Every Drop Count http://repository.tamu.edu:80/retrieve/74176 http://handle.tamu.edu/1969.1/6061 http://handle.tamu.edu/1969.1/88063 Fall 2008, Volume 4, Number 3 2 I Saving for dry days Aquifer storage and recovery may help 8 I Research needs to address ASR challenges 10 I Understanding what lies beneath Groundwater critical to Texas water 14 I Transboundary aquifers Southwestern states assess 18 I Rio Grande project partnerships 24 I Combating soil erosion AgriLife scientist discovering what works for Fort Hood 28 I Blackland’s flood warning system protects soldiers 29 I TWRI Briefs http://handle.tamu.edu/1969.1/88062 Economic Impacts of Salinity Control Measures for the Upper Pecos River Basin of Texas Thompson, William This report presents the results for Subtask 1.7 of the Pecos River Basin Assessment project sponsored by the U.S. Environmental Protection Agency (EPA) and the Texas State Soil and Water Conservation Board (TSSWCB). The original objective of Subtask 1.7 was to measure the economic impact of Tamarix spp. (saltcedar) control along the Texas portion of the Pecos River. As work progressed on other hydrologic studies associated with this project, the scope of the project shifted to analyze the expected economic impacts of implementing potential salinity control measures on the Pecos River above Red Bluff Reservoir to decrease salinity levels in water used for irrigation in Texas. Scenarios evaluated quantified the economic impact of improving water quality used by Texas irrigators to the level of water utilized by the Carlsbad Irrigation District in southern New Mexico. The purpose for this evaluation was to see if the overall economic impact of producing less salt tolerant, more profitable crops might be significant enough to encourage producers to convert current cropping practices to more profitable practices not currently useable due to elevated irrigation water salinity levels. Between 1970-2005, irrigation storage and delivery data from the Red Bluff Water Power Control District (RBWPCD) were analyzed and water delivery from the year 2005 was used as a representative level of available irrigation water. Estimates of current cropping patterns for the irrigated lands within the seven sub-districts of the RBWPCD were established. Data were collected and reviewed for the Carlsbad Irrigation District of New Mexico, just up stream from Red Bluff Reservoir, to establish two estimated alternative cropping patterns under a reduced salinity environment. The differences in the value of farm production between the baseline scenario and the two alternative cropping patterns were entered into the Impact Analysis for Planning (IMPLAN) input-output model of the six county upper Pecos River Basin to quantify the general economic impact to the local economy as a result of changes in current cropping practices. As compared to the typical cropping practices, Alternative 1 reduces the more salt tolerant cotton acreage and moderately tolerant wheat acreage while increasing the acreage of moderately salt sensitive alfalfa. The direct output effect for this alternative cropping pattern was $1,446,206; an increase of 120 percent over the current typical cropping system. The total economic impact to the local economy was $2,807,166 with a net creation of 1.17 full time employee (FTE) jobs. This scenario did not incorporate the impacts to local cotton gins and as a result may be a less desirable option. Alternative 2 maintains cotton acreage, reduces wheat acres, and increases alfalfa acres as compared to typical practices. Compared to Alternative 1, this scenario models one-third of the alfalfa acreage, 5.5 times more acres cotton and equal amounts of wheat. The direct output effect for this alternative cropping pattern was $815,378; an increase of 130 percent over the current typical cropping system. The total economic impact was $1,588,795, and will generate a net increase of 7.8 FTE jobs. 2 The combined effective delivery losses of the Pecos River channel and the sub-district delivery infrastructure have averaged 55.5 percent since 1970. Uncertainty stemming from weather patterns, annual irrigation water availability, and the delivery losses of the current system complicate planning and deter investments by both farmers and irrigation districts making a large-scale conversion from current cropping practices to potentially more profitable practices less likely. In order to increase the likelihood of cropping changes and promote future irrigated agriculture in the basin, a new study of the infrastructure improvements for the RBWPCD and the 7 sub-districts is needed; this was last done in 1991. This study did not measure the impact of increasing available water supplies because it is outside the revised scope of the project and is furthermore an unlikely scenario given the region’s climate. Tremendous increases in grain prices, fuel, and fertilizer costs in recent months can potentially alter economic impacts predicted by this study; these dramatic changes have likely changed demand and production functions of several industries. An updated analysis is needed to better quantify potential economic impacts under the current economic situation. The primary focus of this analysis has been on irrigated farm production; however, the initial intent was to evaluate the economic impacts of saltcedar control in the riparian corridor in general. A large majority of lands in the riparian corridor and watershed are classified as rangelands; which can have a significant impact on the watershed’s economy. Results of a survey of landowners/managers along the Pecos River can be found in appendix 2. This survey was conducted to quantify economic impacts realized by landowners along the river as a result of saltcedar treatment along the river. Generally speaking, these landowners/operators have had little economic benefit or value from the treatment of saltcedar along the Pecos River. http://handle.tamu.edu/1969.1/86505 Implementing Rainwater Harvesting Systems on the Texas A&M Campus for Irrigation Purposes: A Feasibility Study Saour, William Increasing population and increasing urbanization threatens both the health and availability of water resources. The volume and timing of water that is readily available may not be sufficient to supply the demand for potable water in urban areas. Rainwater harvesting is a water conservation strategy that may help alleviate water scarcity and protect the environment. The benefits of collecting rainwater and utilizing it as irrigation water are both tangible and non-tangible. Through collecting and reusing rainwater, grey water may be utilized as a practical resource. Although grey water is not safe to drink, it is safe for other uses such as toilet water, cleaning water, and irrigation. By utilizing rainwater harvesting, a facility saves the cost of purchasing potable water from the local water supply, and the local water supply is not as stressed. In addition, the volume of runoff that flows into local rivers will be reduced, and as a result, the erosion of river banks will be lessened, and ecosystem health may be sustained. The use of rainwater harvesting contributes to the sustainability of building design, calculated using LEED points. This study investigates the water conservation, economic, LEED design, and stormwater benefits of rainwater harvesting for the Texas A&M Campus. With tangible and non-tangible benefits, rainwater harvesting should prove to be a viable and appropriate solution to the conserving and sustaining of natural resources on Texas A&M University’s campus. http://handle.tamu.edu/1969.1/86146 Field Demonstration of the Performance of an Electrocoagulation System to Reduce Phosphorus and Other Substances from Dairy Lagoon Effluent Mukhtar, Saqib Gregory, Lucas Wagner, Kevin Two upper North Bosque River segments were designated as impaired in 1998 due to point source and nonpoint source (NPS) pollution of phosphorus (P) to these segments in the watershed. As a result, two Total Maximum Daily Loads (TMDLs) were applied which called for the reduction of annual loading and annual average soluble reactive P (SRP) concentrations by an average of 50%. This demonstration was conducted to evaluate the efficacy of a prospective new technology, an Electrocoagulation (EC) system, to potentially aid the dairy farmers in meeting the goals set by the TMDLs. This EC system used chemical pre-treatment to coagulate and separate solids in slurry pumped from the dairy lagoon, the liquid then flowed over charged iron electrodes giving off ions that cause coagulation and precipitation of P and other metals. The configuration of the system and its components varied from event to event. To accommodate these changes, the points at which samples were taken varied as well. At all sampling events, samples were taken from the lagoon effluent, the lagoon effluent after the addition of the chemical pre-treatments, the effluent from the EC system and the residual solids. Samples were also taken where the mixture exited the centrifuge after it was added to aid in removing solids. These samples were sent to the lab where they were analyzed for solids, nutrients, metals, pH, and conductivity. In order for the EC unit to function properly, the technology provider removed large amounts of solids from the raw lagoon effluent even though its solid concentration was a low 0.6 mg/L. By the time the treated effluent reached the EC unit, concentrations of many analytes were so low it is hard to conclude whether or not it is an effective component for treating dairy lagoon effluent. Samples of effluent from the centrifuge indicated that it was the most efficient component in the system as it removed larger amounts of solids, as well as more of the nutrients and metals than any other component in the system. Overall, the performance of the system was sporadic from event to event, which may be attributed to the changes in the system that occurred. However, it was consistently effective in reducing total phosphorus (TP) and SRP, on average reducing these constituents by 96% and 99.6% respectively from the dairy lagoon effluent. Some uncertainty surrounds the efficacy of this system to reduce both TP and SRP so efficiently because both these and other nutrients are not stable and do change form. Economic data shows that costs to treat dairy lagoon effluent were $0.12 per gallon ($120 per 1,000 gallons). This cost did not include removal of residual material from the farm and will vary depending on the number of cows and volume of process generated influent entering the lagoon. This price per gallon is considerably higher than traditional methods of sludge treatment that range from $5 to $32 per 1,000 gallons of treated effluent.