The Water Rights Analysis Package (WRAP) modeling system provides capabilities for computer simulation of the management of the water resources of river/reservoir systems and statistical frequency and reliability analyses of simulation results. The modeling system supports assessments of hydrologic and institutional water availability and supply reliability for specified conditions of water development, allocation, regulation, and use. Basin-wide impacts of water resources development projects, changes in water needs, and alternative management strategies can be evaluated. Complex system operations for water supply, environmental flow requirements, hydroelectric energy generation, and flood control can be simulated. Optional salinity simulation capabilities are also included in the modeling system. The software package is generalized for application to systems of rivers and constructed river regulation facilities and associated water management practices anyplace in the world, with input files being developed for the particular river basin, multiple-basin region, or river/reservoir system of concern. The latest version of the WRAP software and manuals along with other relevant publications and datasets may be downloaded through the pages of this website.
WRAP is incorporated in the Texas Commission on Environmental Quality (TCEQ) Water Availability Modeling (WAM) System. An array of information including WRAP simulation input datasets, called WAMs, for all the river basins of Texas is accessible through the TCEQ WAM website. The 15 major river basins and eight coastal basins of Texas are divided into 20 WAM datasets that simulate river system hydrology, operation of 3,460 reservoir projects and other constructed facilities, 6,200 water right permits, water supply contracts, effects of five interstate river basin compacts, and Rio Grande treaties between the U.S. and Mexico. Full authorization and current condition scenario versions of each of the 20 WAMs are available at the TCEQ WAM website.
Applications of the WRAP modeling system in Texas usually involve modifying existing WAM datasets to incorporate alternative proposed water development projects, water management strategies, and/or water use scenarios of interest. Applications outside of Texas require development of input datasets for relevant components of the generalized WRAP modeling system.
The monthly computational time step WRAP modeling system has been routinely applied for many years in Texas in support of regional and statewide planning, project and operational planning, research studies, and administration of the water rights permit system. Recently developed daily WRAP capabilities expand and supplement the monthly model. Daily modeling features expand capabilities for simulating reservoir flood control operations and environmental flow standards with subsistence, base, and high pulse flow components.
The data storage system (DSS) developed by the U.S. Army Corps of Engineers (USACE) Hydrologic Engineering Center (HEC) is incorporated in many HEC and non-HEC modeling systems. HEC-DSS and the DSS interface program HEC-DSSVue are integral components of the WRAP modeling system. HEC-DSSVue is not required to apply WRAP but does greatly enhance the management of WRAP time series datasets. HEC-DSSVue and its user’s manual are available from the HEC website. WRAP applications of DSS files and HEC-DSSVue are covered in the WRAP user’s manual.
WRAP applications range from relatively simple to extremely complex. New model-users should introduce themselves to the modeling system by studying the Fundamentals Manual, which is entitled Fundamentals of Water Availability Modeling with WRAP (TWRI TR-283), and explore modeling capabilities by experimenting with the example dataset that accompanies the Fundamentals Manual. The Fundamentals Manual covers basics relevant to all applications, which may be sufficient for simple applications. The Reference, Users, Daily, Hydrology, and Salinity Manuals provide the detailed explanations of modeling capabilities required for more complex applications.