Applications of Expanded WRAP Modeling Capabilities to the Brazos WAM

The Water Rights Analysis Package (WRAP) is routinely applied in the Texas Commission on Environmental Quality (TCEQ) Water Availability Modeling (WAM) System. However, the Brazos River Basin studies documented by this report represent inaugural applications of the following new WRAP modeling capabilities: (1) conditional reliability modeling to determine short-term storage and flow frequencies and supply reliabilities conditioned on preceding reservoir storage contents; (2) capabilities added to allow simulations to be performed with daily time steps; and (3) simulation of reservoir operations for flood control. The Brazos WAM studies presented in this report provide a data and experience base for evaluating, demonstrating, and developing guidance for applying the new WRAP modeling capabilities. The studies also provide a better understanding of water management in the Brazos River Basin

River System Hydrology in Texas

River/reservoir system hydrology in the 15 major river basins and 8 coastal basins of Texas is explored using information derived from the Water Availability Modeling (WAM) System maintained by the Texas Commission on Environmental Quality and databases maintained by the Texas Water Development Board and the U.S. Geological Survey. River basin volume budgets and trend and frequency metrics for simulated naturalized and regulated stream flows and reservoir storage are developed using the WAM System. Trend and frequency statistics for observed precipitation, reservoir evaporation rates, and stream flow are also developed. Comparative analyses are performed to assess long-term changes. The research supports updating hydrology, incorporating environmental flow standards, and otherwise expanding the WAM System. However, the characterization of river system hydrology has broad general relevance for water resources planning and management. Analyses of long-term changes in hydrology are a central focus of the report, but the information provided describes river system hydrology in general

A framework for a European network for a systematic environmental impact assessment of genetically modified organisms (GMO)

The assessment of the impacts of growing genetically modified (GM) crops remains a major political and scientific challenge in Europe. Concerns have been raised by the evidence of adverse and unexpected environmental effects and differing opinions on the outcomes of environmental risk assessments (ERA). The current regulatory system is hampered by insufficiently developed methods for GM crop safety testing and introduction studies. Improvement to the regulatory system needs to address the lack of well designed GM crop monitoring frameworks, professional and financial conflicts of interest within the ERA research and testing community, weaknesses in consideration of stakeholder interests and specific regional conditions, and the lack of comprehensive assessments that address the environmental and socio economic risk assessment interface. To address these challenges, we propose a European Network for systematic GMO impact assessment (ENSyGMO) with the aim directly to enhance ERA and post-market environmental monitoring (PMEM) of GM crops, to harmonize and ultimately secure the long-term socio-political impact of the ERA process and the PMEM in the EU. These goals would be achieved with a multi-dimensional and multi-sector approach to GM crop impact assessment, targeting the variability and complexity of the EU agro-environment and the relationship with relevant socio-economic factors. Specifically, we propose to develop and apply methodologies for both indicator and field site selection for GM crop ERA and PMEM, embedded in an EU-wide typology of agro-environments. These methodologies should be applied in a pan-European field testing network using GM crops. The design of the field experiments and the sampling methodology at these field sites should follow specific hypotheses on GM crop effects and use state-of-the art sampling, statistics and modelling approaches. To address public concerns and create confidence in the ENSyGMO results, actors with relevant specialist knowledge from various sectors should be involved

Institutional Aspects of Assessing Surface Water Availability

Water resources of river and reservoir systems are shared by many people for diverse, sometimes complimentary but often competing purposes. Effective water management requires a thorough understanding of water availability assessed from a reliability or frequency perspective. The great variability inherent in river system hydrology and the complexities of managing constructed facilities are important considerations in assessing capabilities for meeting water needs. The following two institutional dimensions highlighted in this article are also crucial in water availability modeling

Evaluation of Storage Reallocation and Related Strategies for Optimizing Reservoir System Operations

Statement of the Problem Rapid population and economic growth combined with depleting groundwater reserves are resulting in ever increasing demands on surface water resources in Texas, as well as elsewhere. The climate of the state is characterized by extremes of floods and droughts. Reservoirs are necessary to control and utilize the highly variable streamflow. Due to a number of economic, environmental, institutional, and political considerations, construction of new reservoir projects is much more difficult now than in the past. Consequently, optimizing the beneficial use of existing reservoirs is becoming increasingly more important. Reservoir operation is based on the conflicting objectives of maximizing the amount of water available for conservation purposes and maximizing the amount of empty space available for storing future flood waters to reduce downstream damages. Common practice is to operate a reservoir for either flood control only, conservation only, or a combination of flood control and conservation with separate pools designated for each. The conservation and flood control pools, or vertical zones, in a multipurpose project are fixed by a designated top of conservation (bottom of flood control) pool elevation. Conservation pools may be shared by various purposes, such as water supply, hydroelectric power, and recreation, which involve both complementary and conflicting interactions. Public needs and objectives and numerous factors affecting reservoir operation change over time. An increasing necessity to use limited storage capacity as effectively as possible warrants periodic re-evaluations of operating policies. Reallocation of storage capacity between purposes represents a general strategy for optimizing the beneficial use of limited storage capacity in response to changing needs and conditions. A storage reallocation between flood control and conservation purposes typically involves a permanent or seasonal change in the designated top of conservation pool elevation. Reallocations between conservation purposes can be achieved by various modifications of operating policies. Although given relatively little consideration in the past, storage reallocations will likely be proposed more frequently as demands on limited resources increase. Scope of Study This report documents an investigation of: (1) the potential of storage capacity reallocation and other related modifications in operating policies as management strategies for optimizing the beneficial use of existing reservoirs in Texas and (2) modeling capabilities for formulating and evaluating such changes to operating policies. In general, storage reallocations can involve a variety of types of reservoir use. The present study focused primarily on flood control and water supply. Multiple purpose reservoir operations involving hydroelectric power were also investigated. Both permanent conversion of storage capacity between purposes and seasonal rule curve operations were addressed. Buffer pool operations were also considered. Multiple reservoir system operation was a major emphasis of the study. The literature was reviewed and several reservoir management agencies contacted to (1) identify experiences in studying and/or implementing storage reallocations and (2) evaluate the state-of-the-art of associated modeling and analysis capabilities. The feasibility of seasonal rule curve operation depends upon the seasonal characteristics of the various factors affecting reservoir operation. Precipitation, streamflow, reservoir evaporation, water demands, and reservoir storage content data for Texas were analyzed to identify seasonal characteristics. A 12-reservoir system operated by the U.S. Army Corps of Engineers and Brazos River Authority provided a case study for evaluating the potential for storage reallocations and related operating strategies. This system, located in the Brazos River Basin, is considered representative of major reservoirs in Texas. The existing operating policies and possible modifications were investigated. The case study includes (1) flood control storage frequency and conservation drawdown frequency analyses based on the results of monthly hydrologic period-of-record simulations of reservoir system operations and (2) firm yield and reliability analyses. The generalized computer programs HEC-3, HEC-5, STATS, and MOSS-IV, and several utility software packages were used in the modeling study. Simulation of reservoir system operations was based on an 85-year sequence of monthly hydrologic data. The case study provides a preliminary assessment of the viability of permanent storage conversions and/or adoption of seasonal rule curve operations as potential reservoir management strategies. The objective is to evaluate storage reallocation potentialities in general, not develop detailed reallocation plans. The case study is basically a reconnaissance-level hydrologic analysis of reservoir operations. The monthly period-of-record simulations provide a reasonably precise analysis of water supply considerations. However, the daily hydrologic data required for detailed analysis of flood control operations were not included in the study. Reallocation of reservoir storage capacity involves complex institutional, financial, economic, legal, political, and technical considerations not addressed in the case study. However, the hydrologic analyses provide a good starting point for determining what types of reallocation strategies and modeling approaches might be potentially effective and whether more detailed studies are worthwhile. Organization of the Report Chapter 2 is a general discussion of reservoir operation and institutional and technical aspects of storage reallocation and a review of reallocations which have been implemented or proposed throughout the nation. Chapter 3 addresses the seasonality of the hydrologic factors pertinent to seasonal rule curve operation in Texas. Chapter 4 reviews state-of-the-art modeling capabilities and describes the computer models adopted for use in the case study. The Brazos River Basin case study is presented in chapters 5 through 8. Study results are summarized, and conclusions are presented in chapter 9

Water Rights Analysis Package (WRAP) Users Manual

The Water Rights Analysis Package (WRAP) is documented by a Reference Manual and this Users Manual. The Reference Manual explains WRAP capabilities and methodologies. This Users Manual provides the operational logistics for applying the model. The Users Manual describes the organization of input and output files and the content and format of input records

Water Rights Analysis Package (WRAP) River System Hydrology

The Water Rights Analysis Package (WRAP) is documented by a Reference Manual and Users Manual and several auxiliary manuals including this Hydrology Manual that cover specific aspects of the modeling system. This Hydrology Manual focuses specifically on the WRAP program HYD. The purpose of HYD is to facilitate developing hydrology-related input data for the WRAP simulation model SIM. The purpose of this manual is to document the HYD software

Water Rights Analysis Package (WRAP) Modeling System Reference Manual

The Texas Water Resources Institute (TWRI), and many other agencies and organizations, have worked with Ralph Wurbs over the years to develop WRAP (the Water Rights Analysis Package). The WRAP model simulates management of the water resources of a river basin, or multiple-basin region, under a priority-based water allocation system. The model facilitates assessment of hydrologic and institutional water availability/reliability for existing and proposed requirements for water use and management. Basin-wide impacts of water resources development projects and management strategies may be evaluated. The software package is generalized for application to any river/reservoir/use system, with input files being developed for the particular river basin of concern. The model is documented by reference and users manuals that may be downloaded from this site along with the software. WRAP is incorporated in the Texas Commission on Environmental Quality (TCEQ) Water Availability Modeling (WAM) System