Water Rights Analysis Package Research Articles

Disaggregated monthly SWAT+ model versus daily SWAT+ model for estimating environmental flows in Peninsular Spain

The Water Framework Directive requires all water bodies in EU countries to ensure the ecological integrity of freshwater ecosystems in all water bodies. A “good” status in water bodies leads to their biological elements to reproduce reference conditions, so quantity and timing should be considered in describing environmental flows. However, the availability of daily natural flow data is one of the major drawbacks, especially in highly water-regulated countries, such as Spain, and hydrological models, such as the Soil and Water Assessment Tool (SWAT+) model, can be used to generate them. This work evaluated three different approaches for obtaining daily flows used to characterise the natural regime and to estimate environmental flows in the Piloña River (northern Spain) and Tagus River (centre Spain) basins: Scenario 1) daily flows simulated by the SWAT+ model calibrated on a monthly scale; Scenario 2) daily flows estimated by applying monthly-to-daily disaggregation techniques from the monthly series obtained from the SWAT+ model calibrated on a monthly scale using Water Rights Analysis Package (WRAP) software; and Scenario 3) daily flows simulated by the SWAT+ model calibrated on a daily scale. The Kling–Gupta efficiency (KGE), percent bias (PBIAS), Nash–Sutcliffe efficiency (NSE), root mean square error (RMSE) and standard deviation ratio (RSR) were used to evaluate the model’s performance. Furthermore, the indicators of hydrologic alteration in rivers (IAHRIS) and the basic flow methods were assessed and compared with those obtained directly using the real data observed at the gauging station. Our results indicated that Scenario 2 outperformed the rest of the approaches for all the statistics used. KGE and NSE varied between 0.78 and 0.92 for both basins in Scenario 2 while these values decreased to 0.50–0.60 for KGE and 0.20–0.40 for NSE in Scenarios 1 and 3. Moreover, PBIAS ranged between 3.24 and 4.47% in validation periods in Scenario 2, while it decreased to −14.64% in Scenario 3. Likewise, Scenario 2 was also observed to show better performance related to both the patterns of the natural regime and the basic flow values, which were generally underestimated by the other scenarios. The methodology proposed provides a valuable tool for evaluating and managing the hydrological and environmental status of river basins.

Alternate reservoir operating policies for Lake Victoria in East Africa: A framework for balancing transboundary and local water demands

AbstractThe reliability and impact of several regulation policies on Lake Victoria in East Africa were investigated using the Water Rights Analysis Package (WRAP). Its reliability is determined by establishing the risk of policies failing to meet water demands. The impacts on the lake are evaluated by assessing the effect of policies for lake levels. Policies are based on (i) the lake's firm and safe water yields and (ii) dam turbine configurations at the lake's outlet. The present study demonstrated the applicability of WRAP in modelling large complex reservoirs and determined that constant release policies with a maximum limit of 1015 m3/s have low risks of failure and improve lake water‐level stability.

Modelling interactions between reservoir system operating objectives

ABSTRACT A water availability modelling system implemented in the state of Texas in the United States consists of the generalized Water Rights Analysis Package, which can be applied to river/reservoir systems throughout the world, and datasets for all the river basins of Texas. A monthly version of the modelling system has contributed greatly to improving water allocation and statewide and regional water planning. A recently developed daily version adds capabilities for simulating flood control operations and environmental flow requirements. The simulation study reported here employed the daily modelling system to explore the interactions between the multiple-purposes served by a 12-reservoir system owned by the U.S. Army Corps of Engineers and Brazos River Authority. Interactions between this reservoir system and numerous other water users and reservoirs in the Brazos River Basin are also reflected in the model. The investigation focuses on relationships between water supply, hydropower, flood control, and environmental flow needs.

Statistical Assessments of River Flow Alterations and Environmental Flow Standards

A water availability modeling (WAM) system consisting of the Water Rights Analysis Package (WRAP) and input datasets for all Texas river basins has been used for statewide, regional, and operational planning and water allocation regulatory purposes for many years. The modeling system was recently expanded to support integration of environmental flow requirements in comprehensive water management. A strategy is presented in this paper for combining the WRAP-WAM modeling system with data management and statistical analysis tools to expand capabilities for analyzing stream flow alterations and the effects on flows of environmental flow standards. A Trinity River Basin case study demonstrates the utility of the modeling and analysis strategy in addressing relevant issues in the river systems of Texas and elsewhere. Dams and reservoirs constructed on the Trinity River and tributaries supply water for the Dallas–Fort Worth and Houston metropolitan areas, which are among the most rapidly growing large metro areas in the United States. Ecologically relevant statistical analyses of observed flows presented in this paper are designed to quantify flow alterations. Analyses of simulated flows representing natural and specified conditions of development are performed to assess the impacts of both water resources development and the establishment of environmental flow standards.

Institutional Framework for Modeling Water Availability and Allocation

Effective water resources management requires assessments of water availability within a framework of complex institutions and infrastructure employed to manage extremely variable stream flow shared by numerous, often competing, water users and diverse types of use. The Water Rights Analysis Package (WRAP) modeling system is fundamental to water allocation and planning in the state of Texas in the United States. Integration of environmental flow standards into both the modeling system and comprehensive statewide water management is a high priority for continuing research and development. The public domain WRAP software and documentation are generalized for application any place in the world. Lessons learned in developing and implementing the modeling system in Texas are relevant worldwide. The modeling system combines: (1) detailed simulation of water right systems, interstate compacts, international treaties, federal/state/local agreements, and operations of storage and conveyance facilities, (2) simulation of river system hydrology, and (3) statistical frequency and reliability analyses. The continually evolving modeling system has been implemented in Texas by a water management community that includes the state legislature, planning and regulatory agencies, river authorities, water districts, cities, industries, engineering consulting firms, and university researchers. The shared modeling system contributes significantly to integration of water allocation, planning, system operations, and research.

Assessment of watershed characteristics with limited water quantity and quality data.

The evaluations of water quantity and quality and then modeling of its phenomenon are required for water quality protection in Brady Creek watershed. This study is to predict the monthly flow, reservoir storage volume, and salinity; estimate the benefit of brush and aging flood-retardation dam control; and evaluate the impact of evaporation and discharge from Waste Water Treatment Plans (WWTP). The Soil and Water Assessment Tool (SWAT) model is verified with the monthly flow developed for pre-dam construction condition and shows the difference of - 9% and 10% than measured average flow for calibration and validation periods, respectively. The SWAT monthly flows are adjusted by 1963-2010 yearly conversion factors and are used as the input in the Water Rights Analysis Package (WRAP) model. The WRAP model verified with measured reservoir storage volume and total dissolved solid shows the average differences of simulated reservoir storage volume and salinity by - 13% lower and 11% higher for calibration period and 0% and 3% higher for validation period than measured average value, respectively. The impacts from brush and dams controls increase the runoff but also increase the water quality parameters. The impact of evaporation and WWTP discharge provide the information of relative impact for watershed phenomenon.

Reliability Variability Assessment for Water Rights by Simplifying Stage-Discharge Curves

Input generation of the Water Rights Analysis Package (WRAP) was performed in this study, focusing on the upstream and downstream gage stations located at Soyang Dam. The rating curves for stage and discharge were divided into several ranges, corresponding to each stage. Subsequently, these stages were separated into high, medium, and low stages. Regression curves corresponding to each stage were then established. The streamflow simulated using the regression curve and gaged streamflow was used to compute reliability for water rights. The volume reliability shows a difference of 0.12% between the two kinds of streamflows for the 2006∼2015 hydrological simulation period. This study contributes towards application of the WRAP model by developing a procedure for generating simplified streamflows. Keywords: WAMIS, Naturalized Stream Flow, Probability Distribution Curve

Long-term changes in river system hydrology in Texas

Abstract. Climate change and human actives are recognized as a topical issue that change long-term water budget, flow-frequency, and storage-frequency characteristics of different river systems. Texas is characterized by extreme hydrologic variability both spatially and temporally. Meanwhile, population and economic growth and accompanying water resources development projects have greatly impacted river flows throughout Texas. The relative effects of climate change, water resources development, water use, and other factors on long-term changes in river flow, reservoir storage, evaporation, water use, and other components of the water budgets of different river basins of Texas have been simulated in this research using the monthly version of the Water Rights Analysis Package (WRAP) modelling system with input databases sets from the Texas Commission on Environmental Quality (TCEQ) and Texas Water Development Board (TWDB). The results show that long-term changes are minimal from analysis monthly precipitation depths. Evaporation rates vary greatly seasonally and for much of the state appear to have a gradually upward trend. River/reservoir system water budgets and river flow characteristics have changed significantly during the past 75 years in response to water resources development and use.

Environmental flow requirements in a water availability modeling system

Abstract The Texas Water Availability Modeling (WAM) System consists of the generalized Water Rights Analysis Package (WRAP), which is applicable for river systems located anywhere, and WRAP input datasets for the river basins of Texas. The WRAP/WAM system has been applied for over a decade in planning studies and administration of a water rights allocation system. Environmental flow standards for selected river systems in Texas have recently been established through a legislatively mandated process based on flow regimes with subsistence, base, pulse, and overbank flow components that describe the magnitude, frequency, duration, and timing of flows required to maintain sound ecosystems. WRAP and WAM capabilities for integrating environmental flow requirements in water allocation and associated water availability modeling have been greatly expanded as necessary to implement the new environmental flow standards. The modeling system and lessons learned in its implementation in Texas are relevant elsewhere.

Environmental Flow Attainment Metrics for Water Allocation Modeling

AbstractEnvironmental flow standards established according to a consensus-based, legislatively mandated process are being incorporated in the water rights permitting system for selected priority river systems in Texas. The flow standards for several of the rivers have been simulated as a part of a university research study using the new daily version of the Water Rights Analysis Package (WRAP) modeling system with modified input data sets from the Texas Commission on Environmental Quality (TCEQ) Water Availability Modeling (WAM) system. Metrics have been evaluated using time series of simulated streamflows and flow targets to characterize the engagement and attainment of the environmental flow standards. The metrics help determine the extent to which the standards are achieved within a river system water allocation simulation and enable the comparison of results between the different environmental flow regime components, different locations, and alternative river system development scenarios.

단일 저수지 운영에서 우선 수리권 영향성 평가

Nowadays, global warming derived from urbanization makes impact on the climatical and natural environment in the world. Also, water shortage from sharp population growth has increased because of impossible condition of the new reservoir construction that is one of sustainable water resource development. Accordingly, data survey for water rights have been required for limited water resources distribution effectively. Now, Water Management Information System(WAMIS) has gathered domestic water rights data according to various criteria as follows: living, industrial, and agricultural use purposes for specific year based on watershed, basin, river size. In this study, Water Rights Analysis Package (WRAP), one component of Texas Water Availability Model (WAM) system, is applied to multi-purpose Soyang Dam with monthly flow, evaporation, and precipitation. Also, water rights data are utilized into two types: natural and priority order water rights. The application results indicated that two types of water rights provided the insight for establishing various reservoir operation plans under flood, normal, and drought periods.

Generation of daily naturalized flow at ungaged control points

The development of daily naturalized flow in the water rights analysis package (WRAP) model at ungaged stations has difficulties because of low daily flow measurement at gaged stations, low available monthly naturalized flow, and budget constraints. This study proposes a procedure for developing daily naturalized flow at ungaged stations. The soil and water assessment tool (SWAT) model was validated with little daily flows and used for predicting the daily flow at gage stations that are near ungaged stations. The predicted daily flow is transferred at ungaged stations using the drainage area ratio (DAR) method. The transferred daily flow is aggregated and compared with monthly regulated flow computed by the WRAP model with the mean, standard deviation, mean relative error, Nash–Sutcliffe model efficiencies, and correlation coefficient ( R 2 ). The SWAT daily flow, which is referred to as the regulated flows, is converted using regression equations into naturalized flow and used as the daily pattern flow for monthly naturalized flow disaggregation. The system application of the SWAT and WRAP models with DAR and pattern methods provides alternative ways to generate daily naturalized flow at ungaged stations through disaggregating monthly naturalized flow at primary stations.

Institutional and Hydrologic Water Availability in Texas

The Water Availability Modeling (WAM) System created and maintained by the Texas Commission on Environmental Quality (TCEQ) and its partner agencies and contractors consists of the generalized Water Rights Analysis Package (WRAP) developed at Texas A & M University, which may be applied anywhere in the world, and WRAP input datasets for the 23 river basins of Texas. WRAP is designed for assessing river/reservoir system reliabilities in meeting water supply, hydroelectric power, environmental flow, flood control, and reservoir storage needs. The Texas WAM System supports regional and statewide planning, administration of water allocation systems, and other water resources management endeavors. Activities of numerous water management entities operating 3,435 reservoirs and other facilities in accordance with treaties between the United States and Mexico, five interstate compacts, two water right permit systems with 6,000 active permits, and other institutional arrangements are simulated. The modeling system contributes greatly to water management in Texas and continues to be expanded to address additional water management issues. The Texas experience in implementing the WAM System illustrates key aspects of evaluating water availability from institutional as well as hydrologic perspectives.

Short-Term Reservoir Storage Frequency Relationships

AbstractThe water rights analysis package (WRAP) is a generalized river/reservoir system simulation model that is routinely applied in Texas in regional and statewide planning studies and administration of the water right permit system. The WRAP modeling system was recently expanded by adding short-term storage frequency and supply reliability analysis capabilities. Individual reservoirs and multiple-reservoir systems can be analyzed considering numerous water users and complex water management practices. The new modeling features are based on dividing the hydrologic period-of-analysis into many short-simulation sequences with each starting with the same storage conditions. Two alternative frequency/reliability analysis methodologies, called the equal-weight and probability-array options, are compared in this paper with a case-study application. The probability array option is designed to improve the accuracy of storage frequency estimates by modeling hydrologic persistence as reflected in the preceding r...

Modeling river/reservoir system management with the expanded WRAP

The Water Rights Analysis Package (WRAP) is a generalized modeling system for simulating water resources development, management, allocation, and control in river basins located anywhere in the world. WRAP is used to assess reliabilities in meeting water supply, hydroelectric power, and environmental instream flow needs. Capabilities for tracking salinity, assessing short-term reliabilities, and simulating reservoir operations for flood control were recently added. The modeling system continues to be expanded to address a broadening range of applications with major new modeling capabilities being released during 2009–2010. The Texas Water Availability Modeling (WAM) System consists of the generalized WRAP and input datasets for the 23 river basins of Texas. The Texas WAM System supports regional and statewide planning, administration of a water allocation permit system with over 8,000 active permits, and other water resources management functions. Activities of an array of water management entities operating 3,435 reservoirs and other facilities in accordance with various water allocation systems and other institutional arrangements are modeled.

Development of monthly naturalized flow using Water Rights Analysis Package (WRAP)-based methods

This paper addresses the methodology for developing monthly naturalized flow of the Texas Water Availability Model (WAM) system datasets by developing and applying Water Rights Analysis Package (WRAP)-based methods. The methodology is based on converting gaged stream flows adjusted to remove human impacts to naturalized flows using a current use WRAP model input dataset from the WAM System modified to represent actual use. An actual use scenario dataset is developed by modifying the current use scenario dataset to better represent actual water resources development, allocation, management, and use. The simulation iterations continue until the regulated flows very closely match the actual gaged flows. The regulated flow computed using the new naturalized flow shows the close match to gaged flow. The methodology developed in this study could potentially be used to update the other river basin datasets in the statewide WAM System.

Incorporation of salinity in Water Availability Modeling

Summary Natural salt pollution from geologic formations in the upper watersheds of several large river basins in the Southwestern United States severely constrains the use of otherwise available major water supply sources. The Water Rights Analysis Package modeling system has been routinely applied in Texas since the late 1990s in regional and statewide planning studies and administration of the state’s water rights permit system, but without consideration of water quality. The modeling system was recently expanded to incorporate salinity considerations in assessments of river/reservoir system capabilities for supplying water for environmental, municipal, agricultural, and industrial needs. Salinity loads and concentrations are tracked through systems of river reaches and reservoirs to develop concentration frequency statistics that augment flow frequency and water supply reliability metrics at pertinent locations for alternative water management strategies. Flexible generalized capabilities are developed for using limited observed salinity data to model highly variable concentrations imposed upon complex river regulation infrastructure and institutional water allocation/management practices.

River Flows for Alternative Conditions of Water Resources Development

The Texas water availability modeling (WAM) system consists of the water rights analysis package (WRAP) river/reservoir system simulation model, which is generalized for application any place in the world, and WRAP input data sets for all of the river basins of Texas. The WRAP/WAM system combines historical natural river basin hydrology with specified scenarios of water resources development, management, and use. Multiple-year sequences of monthly river flows for natural and alternative conditions of development are simulated. The paper compares flow-frequency statistics for nine major Texas rivers under natural and current conditions. The WRAP modeling system was recently expanded to provide flexible additional capabilities to develop stream flows representing various other user-specified conditions. An investigation of the Brazos River Basin demonstrates the new methodologies for adjusting river flows to reflect specified water management scenarios of interest.

Raster‐network regionalization for watershed data processing

Difficulties exist in calculating watershed parameters from raster datasets over large regions because of the excessive computation time involved. A technique is presented which divides a large region into hydrologically distinct subregions, in each of which raster analyses are performed, in order to efficiently process large raster datasets. The results of raster analyses are stored as attributes on the resulting vector data. The vector data are then merged, and appropriate values accumulated to obtain regional parameter values for points of interest along the stream network. The technique, called Raster‐Network Regionalization, uses the vector stream network as the backbone for the integration of subregions into a single region. A case study is presented which utilizes the technique to prepare geospatial inputs for the Water Rights Analysis Package simulation model.

Conditional Reliability Modeling of Short-Term River Basin Management

A conditional reliability model (CRM) is presented for assessing reliabilities for meeting water needs over the next several months, conditioned upon current reservoir storage contents. The CRM procedure was developed in conjunction with a generalized river/reservoir system model called the Water Rights Analysis Package (WRAP). The CRM methodology is presented in the context of the WRAP model, but the process is applicable to other models as well. A new concept of conditional frequency duration curves, representing probability distributions of naturalized streamflows conditioned on preceding simulated reservoir storage, is incorporated in the CRM methodology. The results of the model are probability-weighted values of storage or diversion from many short-term simulations that start with the same storage condition. Applications of the model in annual operational planning, drought contingency planning, and reservoir resilience analysis are presented, along with pertinent discussions of the fundamental concepts of the model and comparison with the alternative, simpler approach of assuming each short-term simulation is equally likely to occur.