AN INTERDISCIPLINARY APPROACH TO VALUING WATER FROM BRUSH CONTROL1

ABSTRACT: An analytic methodology utilizing models from three disciplines is developed to assess the viability of brush control for water yield in the Frio River basin, Texas. Ecological, hydrologic, and economic models are used to portray changes in forage production and water supply resulting from brush control, and to value supplemental water produced through brush control. Site‐specific biophysical characteristics are used to simulate water yields from brush control across the watershed. Economic benefits from increased animal production for ranchers undertaking brush control are assessed. Benefits to Corpus Christi residential water consumers from ranchers' brush control activities are evaluated using the change in consumer surplus resulting from supplemental water produced through brush control. Results indicate an increase in water yield with brush control on 35 percent of the land area in the basin. However, the cost of brush control is more than the increase in returns it fosters on most range sites. Consumer surplus change for Corpus Christi residents over 25 years is zero under baseline conditions, implying subsidies for brush control in the Frio basin are not worthwhile at this time.     

MODELING THE EFFECT OF BRUSH CONTROL ON RANGELAND WATER YIELD1

ABSTRACT: With the increase in water demand in Texas, attention has turned to improving water yield by brush control on rangeland watersheds. Several hydrologic models have been developed for either farmland or rangeland. However, none of the models were specifically developed to assess the impact of brush control on rangeland water yield. Yet, modeling the impact of brush control on water yield needs to be considered if alternative techniques are to be compared. Two models, Ekalaka Rangeland Hydrology and Yield Model (ERHYM-II) and Simulator for Water Resources on Rural Basins (SWRRB) were selected. The Soil Conservation Service curve number (SCS-CN) method is used in both models to predict surface runoff from each rainfall event. The major differences between the ERHYM-II and SWRRB models are the evapotranspiration, soil water routing, and plant growth components. The models were evaluated on brush-dominated and chemically and mechanically brush-controlled range watersheds in Texas. Results indicated that both models were capable of simulating soil water and water yield from brush dominated and chemically brush-controlled range watersheds. The models were not able to predict water yield from the mechanically brush-controlled (root plowed) watershed with acceptable accuracy. The depressions that were caused by root plowing stored surface runoff and reduced water yield from the watershed. Information about the size of depressions was not available for further model evaluation.     

WATER YIELD IMPROVEMENT POTENTIAL BY VEGETATION MANAGEMENT ON WESTERN RANGELANDS1

Increasing water for onsite and offsite uses can be a viable objective for management of certain western rangelands. One approach utilizes water harvesting techniques to increase surface runoff by preventing or slowing infiltration of rain. An attractive alternative, where applicable, is to replace vegetation that uses much water with plants that use less so that more water percolates through the soil to streams and ground water. Most sites are too dry to increase water yield in this way; probably less than 1 percent of the western rangelands can be managed for this purpose. However, where annual precipitation exceeds about 450 mm (18 inches) and deep-rooted shrubs can be replaced by shallow-rooted grasses, there is potential to increase streamflows and to improve forage for livestock. Little or no increase can be expected by eradication of low-density brush and pinyon-juniper woodlands. Potentials for improving water yield are reviewed and summarized by vegetation types.     

WATER YIELD AUGMENTATION THROUGH FOREST AND RANGE MANAGEMENT - ISSUES FOR THE FUTURE1

The demand for more water is increasing throughout the country. Research on upland watersheds clearly demonstrates that water yield can be increased using forest and range management practices. Based on the experience of the past several decades and a review of six papers in a recent AWRA series on water yield augmentation through vegetation management, the following issues and concerns are discussed: predicting increased yields from large basins; economic evaluation of additional flows; court acceptance and need for system models; the legal question of ownership and transferability of increased yields; and management emphasis on private and federal lands. The immediate potential for water yield augmentation is on carefully selected watersheds that have the bio-physical potential to produce high value water under environmentally acceptable multiple use management. We predict water yield management on a broader scale will result from increased pressures to solve the legal and economic issues involved.     

CONJUNCTIVE MANAGEMENT OF WATER RESOURCES IN THE CONTEXT OF TEXAS WATER LAW1

ABSTRACT: This paper examines the critical interaction between existing Texas water law and the state's water resources. Conjunctive use and management of interrelated water resources, though seldom practiced, is generally considered desirable. However, a significant barrier to the coordinated, efficient use and management of water resources is the legal division of water in the various phases of the hydrologic cycle into different classes and recognition of well-defined water rights in the separate phases. Several examples of the problems which relate to, or result from, present Texas water law and which prevent correlated water resource management are discussed. Any substantive revision of Texas law, particularly ground water law, will apparently be difficult to achieve in the immediate future, primarily because of the large number of recognized private water rights and the political power inherent in them. Data necessary for operation of conjunctive management systems are gradually being acquired, and perhaps someday other hydrologic phases can be integrated with surface and ground water. Nevertheless, Texas courts and the legislature have sufficient information on the interrelated hydrologic cycle so that prospective water conflicts should be anticipated and avoided. Great care must be exercised in the recognition of new types of private water rights or extension of existing rights, because this institutional structure, once established, presents a formidable obstacle to desirable revisions of the law.     

THE STRUCTURE AND ROLE OF RIVER AUTHORITIES IN TEXAS1

ABSTRACT: Texas river authorities are a type of large, regional water district that must be financially self-sufficient. An institutional and historical study of Texas river authorities reveals the broad power of these organizations and their influence in water management. River authorities now control 25 percent of surface water deliveries in Texas. Over two-thirds of authority water was developed by river authorities; nearly one-third was purchased from private or public ventures. While river authority activities have been effective where these services are marketable, the provision of public good services is limited. Increased visibility of these organizations is paralleled by challenges to their traditional autonomy.     

Managing Forests for Increased Regional Water Yield in the Southeastern U.S. Coastal Plain

With growing populations fueling increased groundwater abstraction and forecasts of greater water scarcity in the southeastern United States, identifying land management strategies that enhance water availability will be vital to maintaining hydrologic resources and protecting natural systems. Management of forested uplands for lower basal area, currently a priority for habitat improvement on public lands, may also increase water yield through decreased evapotranspiration (ET). To explore this hypothesis, we synthesized studies of precipitation and ET in coastal plain pine stands to develop a statistical model of water yield as a function of management strategy, stand structure, and ecosystem water use. This model allowed us to estimate changes in water yield in response to varying management strategies across spatial scales from the individual stand to a regional watershed. Results suggest that slash pine stands managed at lower basal areas can have up to 64% more cumulative water yield over a 25‐year rotation compared to systems managed for high‐density timber production, with the greatest increases in stands also managed for recurrent understory fire. Although there are important uncertainties in the magnitude of additional water yield and its final destination (i.e., surface water bodies vs. groundwater), this analysis highlights the potential for management activities on public and private timber lands to partially offset increasing demand on surface and groundwater resources.     

ESTIMATING THE PUBLIC'S VALUES FOR INSTREAM FLOW: ECONOMIC TECHNIQUES AND DOLLAR VALUES1

ABSTRACT: Sound water resource management requires comparison of benefits and costs. Many of the perceived benefits of water relate to providing instream flow for recreation and endangered fish. These uses have value but no prices to guide resource allocation. Techniques to estimate the dollar values of environmental benefits are presented and illustrated with several case studies. The results of the case studies show that emphasis on minimum instream flow allocates far less than the economically optimum amount of water to instream uses. Studies in Idaho demonstrated that optimum flows that balance benefits and costs can be ten times greater than minimum flows. The economic benefits of preserving public trust resources outweighed the replacement cost of water and power by a factor of fifty in California. While it is important to incorporate public preferences in water resource management, these economic survey techniques provide water managers with information not just on preference but how much the public is willing to pay for as well. This facilitates comparison of the public costs and benefits of instream flows.     

Managing the Commons Texas Style: Wildlife Management and Ground‐Water Associations on Private Lands1

Abstract: As nearly all of Texas’ rural lands are privately owned, landowner associations for the management of white‐tailed deer and ground‐water have become increasingly popular. Deer are a common‐pool resource with transboundary characteristics, requiring landowner cooperation for effective management. Ground‐water reserves are economically important to landowners, but are governed by the “rule of capture” whereby property rights are not defined. One ground‐water association and four wildlife management associations (WMAs) were surveyed to characterize their member demographics, land use priorities, attitudes, and social capital. Members of the ground‐water cooperative were part of a much larger, more heterogeneous, and more recently formed group than members of WMAs. They also placed greater importance on utilitarian aspects of their properties, as opposed to land stewardship for conservation as practiced by members of WMAs. If ground‐water association members could be more locally organized with more frequent meetings, social capital and information sharing may be enhanced and lead to land stewardship practices for improved hydrologic functions and sustained ground‐water supply. This, coupled with pumping rules assigned by the local ground‐water district, could yield an effective strategy that is ecologically and hydrologicaly sound, and that allows rural provision of water supply to urban consumers.     

APPROACHES TO WATER RESOURCE POLICY AND PLANNING IN TEXAS1

ABSTRACT: Texas is one of the states in which limitations in water supplies could severely constrain economic growth in certain areas. The traditional planning approach for addressing this problem has involved devising schemes for large water development projects, which for many years included the importation of water from other states. Now the attitude towards water resource management is changing, and it is generally agreed that better management of existing supplies is the preferred approach. In this paper we review some of the changes that have recently occurred in Texas, including attempts to streamline the water institutions in such a way that they might be more responsive to the need for more comprehensive management of water resources statewide, with greater emphasis on social and environmental concerns.     

Water Prism: A Tool to Assess Water Availability Risk and Investigate Water Management Strategies

Water availability risk is a local issue best understood with watershed‐scale quantification of both withdrawal and consumptive demands in the context of available supply. Collectively, all water use sectors must identify, understand, and respond to this risk. A highly visual and computationally robust decision support tool, Water Prism, quantitatively explores mitigation responses to water risk on both a facility‐level and basin‐aggregated basis. Water Prism examines a basin water balance for a 40‐ to 60‐year planning horizon, distinguishes among water use sectors, and accounts for ecosystem water needs. The 2012 Texas State Water Plan was used to apply Water Prism to the Big Cypress‐Sulphur Basin (Texas). The case study showed Water Prism to be an accurate and convenient tool to provide fine‐scale understanding of water use in the context of available supply, evaluate multi‐sector combinations of conservation strategies, and quantify the effects of future demands and water availability. Analyses demonstrated water availability risks for rivers and reservoirs can vary within a basin and must be calculated independently, simulation of water balance conditions can help illuminate potential impacts of increasing demands, and scenario simulations can be used to evaluate relative conservation efficacy of different water resource management strategies for each sector. Based on case study findings, Water Prism can serve as a useful assessment tool for regional water planners.     

Science and Decision Making: Water Management and Tree‐Ring Data in the Western United States1

Abstract: Growing populations, limited resources, and sustained drought are placing increased pressure on already over‐allocated water supplies in the western United States, prompting some water managers to seek out and utilize new forms of climate data in their planning efforts. One source of information that is now being considered by water resource management is extended hydrologic records from tree‐ring data. Scientists with the Western Water Assessment (WWA) have been providing reconstructions of streamflow (i.e., paleoclimate data) to water managers in Colorado and other western states (Arizona, New Mexico, and Wyoming), and presenting technical workshops explaining the applications of tree‐ring data for water management for the past eight years. Little is known, however, about what has resulted from these engagements between scientists and water managers. Using in‐depth interviews and a survey questionnaire, we attempt to address this lack of information by examining the outcomes of the interactions between WWA scientists and western water managers to better understand how paleoclimate data has been translated to water resource management. This assessment includes an analysis of what prompts water managers to seek out tree‐ring data, how paleoclimate data are utilized by water managers in both quantitative and qualitative ways, and how tree‐ring data are interpreted in the context of organization mandates and histories. We situate this study within a framework that examines the coproduction of science and policy, where scientists and resource managers collectively define and examine research and planning needs, the activities of which are embedded within wider social and political contexts. These findings have broader applications for understanding science‐policy interactions related to climate and climate change in resource management, and point to the potential benefits of reflexive interactions of scientists and decision makers.     

INSTITUTIONS AND TECHNOLOGY: KEYS TO BETTER WATER MANAGEMENT1

Seven considerations which bear upon the achievement of better water management are discussed. First, separation of judgments of fact from judgements of value is helpful in deciding upon what actions to take. Second, separation of social values from matters of individual or group interest is crucial to institutional design. Third, achieving economically efficient water management may create a surplus of benefits which can be divided among the parties in order to resolve conflicts. Fourth, surpluses also can be used inappropriately, whether to reward undesirable behavior or to penalize unjustly. Fifth, avoidance of external costs is best achieved through restructuring of rewards and penalties. Sixth, technological solutions are too easily selected in place of less costly institutional change. Seventh, water management technology is too often selected in place of more cost-effective, water-related technology. Selected examples of each of these considerations are offered. However, better water management is not easy to define. The social process criterion adopted in this paper is discussed briefly.     

The Water Market for the Middle and Lower Portions of the Texas Rio Grande Basin1

Leidner, Andrew J., M. Edward Rister, Ronald D. Lacewell, and Allen W. Sturdivant, 2011. The Water Market for the Middle and Lower Portions of the Texas Rio Grande Basin. Journal of the American Water Resources Association (JAWRA) 47(3):597‐610. DOI: 10.1111/j.1752‐1688.2011.00527.x Abstract: Regional water management on the United States’ side of the middle and lower portions of the Rio Grande basin of Texas has been aided by a functioning water market since the early 1970s. The water market operates over a region that stretches from the Amistad Reservoir to the Rio Grande’s terminus into the Gulf of Mexico. This article provides an overview of the organizations, institutions, policies, and geographic particulars of the region’s water‐management system and its water market. In recent years, this region has experienced high population growth, periodic droughts, and a reallocation of water resources from the area’s agricultural sector to the municipal sector. Demand growth for potable water and a relatively fixed supply of raw water are reflected in increasing prices for domestic, municipal, and industrial water rights. Rising prices in the presence of scarcity and the transfer of water from lower‐value to higher‐value uses indicate that the market is operating as suggested by economic theory. Reasons for the market’s functionality are presented and discussed. Finally, suggestions are presented which might mitigate potential complications to market operations from aquifer depletion and aid the management of instream river flows.     

Simulation of vegetation dynamics and management strategies on south Texas, semi-arid rangeland

In this paper, we describe a model designed to simulate seasonal dynamics of warm and cool season grasses and forbs, as well as the dynamics of woody plant succession through five seral stages, in each of nine different plant communities on the Rob and Bessie Welder Wildlife Refuge. The Welder Wildlife Refuge (WWR) is located in the Gulf Coastal Prairies and Marshes ecoregion of Texas. The model utilizes and integrates data from a wide array of research projects that have occurred in south Texas and WWR. It is designed to investigate the effects of alternative livestock grazing programs and brush control practices, with particular emphasis on prescribed burning, the preferred treatment for brush on the WWR. We evaluated the model by simulating changes in the plant communities under historical (1974-2000) temperature, rainfall, livestock grazing rotation, and brush control regimes, and comparing simulation results to field data on herbaceous biomass and brush canopy cover collected on the WWR over the same period. We then used the model to simulate the effects of 13 alternative management schemes, under each of four weather regimes, over the next 25 years. We found that over the simulation period, years 1974-2000, the model does well in simulating the magnitude and seasonality of herbaceous biomass production and changes in percent brush canopy cover on the WWR. It also does well in simulating the effects of variations in cattle stocking rates, grazing rotation programs, and brush control regimes on plant communities, thus providing insight into the combined effects of temperature, precipitation, cattle stocking rates, grazing rotation programs, and brush control on the overall productivity and state of woody plant succession on the WWR. Simulation of alternative management schemes suggests that brush canopy removal differs little between summer and winter prescribed burn treatments when precipitation remains near the long-term average, but during periods of low precipitation canopy removal is greater under winter prescribed burning. The model provides a useful tool to assist refuge personnel with developing long-term brush management and livestock grazing strategies.     

THE MISUSE OF HYDROLOGIC UNIT MAPS FOR EXTRAPOLATION,REPORTING, AND ECOSYSTEM MANAGEMENT1

ABSTRACT: The use of watersheds to conduct research on land/water relationships has expanded recently to include both extrapolation and reporting of water resource information and ecosystem management. More often than not, hydrologic units (HUs) are used for these purposes, with the implication that hydrologic units are synonymous with watersheds. Whereas true topographic watersheds are areas within which apparent surface water drains to a particular point, generally only 45 percent of all hydrologic units, regardless of their hierarchical level, meet this definition. Because the area contributing to the downstream point in many hydrologic units extends far beyond the unit boundaries, use of the hydrologic unit framework to show regional and national patterns of water quality and other environmental resources can result in incorrect and misleading illustrations. In this paper, the implications of this misuse are demonstrated using four adjacent HUs in central Texas. A more effective way of showing regional patterns in environmental resources is by using data from true watersheds representative of different ecological regions containing particular mosaics of geographical characteristics affecting differences in ecosystems and water quality.     

Modeling the impact of revegetation on regional water quality: A collective approach to manage the cumulative impacts of mining in the Bowen Basin,Australia

In this paper we quantify the additional water quality benefits that can be achieved through coordinated cumulative impact management. To do this we simulate coordinated and un-coordinated revegetation investments and compare their impact on achieving regional water quality goals. Our results show that coordination between multiple mining companies achieves additional benefits since prioritization is enabled across a broader range of investment opportunities. Additionally, when coordinated investment is permitted beyond the boundaries of coal mining leases, results show that additional benefits are greatly enhanced since these regions provide more rewarding investment opportunities. Results illustrate (a) how regional coordination may influence reputational benefits of investments, and (b) that coordination is beneficial when investment opportunities are unevenly distributed across the landscape. When additional benefits are achievable, we suggest that mining companies should develop collective investment projects with an understanding of how coordination influences project costs. Similarly, investment projects should be developed with an understanding of investment tradeoffs and how these may adversely impact on regional stakeholders and hence industry reputation. The mining industry has significant potential to contribute to regional wellbeing; however, land management policies must be flexible and promote incentives to enable companies to invest beyond compliance.     

THE EFFECTS OF WATER RESOURCES DEVELOPMENT ON ESTUARINE ENVIRONMENTS1

ABSTRACT. The Texas Water Development Board, the principal water resource planning agency of the State, has been conducting extensive estuarine data collection activities and associated research to determine the required quantity and quality of fresh water inflows necessary to maintain various environmental conditions in Texas estuaries to preserve the estuarine ecosystems. These activities are a consequence of a statutory directive to the Board to make provisions in its State Water Plan for the effects of upstream water resource development on the associated estuaries. This paper reports on the results of the first phase of an extensive estuarine research project. The objectives of the research project are to (1) define the interrelationships between estuarine ecosystems and fresh water and nutrient inflows, and (2) develop and test quantitative simulation techniques which describe these relationships. In order to accomplish the first objective, physical and chemical water quality data and biological data on the estuarine ecosystems are being collected, compiled and analyzed. The second objective is being satisfied by the development of hydrodynamic and ecologic simulation models of the estuarine environment.