Bangladesh and India share 54 transboundary rivers. Despite that, the transboundary water management between these two countries is heavily concentrated on the Ganges river basin, in which, mode of cooperation is still based on physical sharing of water. The study is developed on the argument that Bangladesh and India need a shift of focus in their current mode of transboundary water management from physical sharing of water to sharing of benefits derived from the use (and non-use) water in order to foster transboundary water cooperation in the Ganges river basin. Based on a single-case study, the research work aims to explore the scope of benefit-sharing in the transboundary water cooperation in the Ganges river basin and how benefit-sharing can be facilitated between these two countries. The findings show that the water negotiation in the Ganges basin would become much more complicated in the future, primarily due to the growing gap between the demand and the availability of water. The adverse impact of climate change will further deteriorate the situation. Besides, the changing nature of India’s domestic politics and the growing internal conflict between its provincial states will weaken the Indian central government’s authority to manage transboundary water resources jointly. Therefore, in the future, Bangladesh and India would find it difficult to elicit a positive-sum outcome from any water negotiation in Ganges river if they still focus on the volumetric allocation of water. The study suggests that inland navigation and water transit, multipurpose storage dam projects and joint management of the Sundarbans can be the potential areas for benefit-sharing in the Ganges basin. The study stresses the importance of shifting the policy outlook and developing institutional arrangements between Bangladesh and India to introduce and facilitate benefit-sharing in the Ganges river basin that will help to share benefits equitably, hence foster cooperation.

Disaster risk reduction policies and practitioners alike emphasise the importance of vulnerability reduction. However, the concept of vulnerability is highly dynamic, and research still strives to understand and capture its complexity. The purpose of this study was to improve the understanding of flood vulnerability in rural disaster-prone communities in Mozambique. To explore previous experiences of floods, I conducted semi-structured interviews with local risk committee members and community members in the lower Limpopo river basin. The findings were analysed with an analytical framework consisting of the Disaster Pressure and Release (PAR) model, drawing on political ecology and the Access model. Disaster was studied as a process revealing important factors, capabilities and strains affecting peoples’ vulnerability. This paper illustrated that rural communities in the lower Limpopo river basin are vulnerable to floods in a variety of ways. The findings presented unsafe conditions such as the fragile local economy, unsafe natural resources, strained physical resources and limited access to human and social capital. Several factors deriving from political, social and economic structures were found to influence specific forms of vulnerability expressed in relation to floods. Therefore, this paper contributes to new insights of how flood vulnerability can be described and explained in Mozambique.

This thesis provides an analysis how social learning can be supported during the implementation of the WFD. Four research questions address the different characteristics of river basin management: 1) How do spatial misfits between participatory and decision-making institutions impede social learning"2) Does the formalized context of river basin management in Europe allow for social learning" 3) What are conducive environments for social learning in river basin management" 4) How does research contribute to social learning in river basin management" What challenges arise in applied research"The concept of social learning (SL), especially as developed in the European project HarmoniCOP (www.harmonicop.uos.de), formed the theoretical backbone of the analysis. This allowed to consider the challenge of SL to be supported by process design or the institutional settings. At the same time, it allowed to understand to which extent the efficiency of this support depends on the question whether or not the participants in the process recognize the options for improving their knowledge base and make use of them. The analyses have been mainly based on a German case study on the international Elbe river basin district, which was embedded in the European project HarmoniCOP. Here, the specific challenges (spatial misfit; the need for collaboration in formalized contexts) have been addressed exploring participatory and other collaboration processes as well as the actors approach to SL. In order to understand collaboration processes between research and water management, the role of research in delivering tools to support the new challenges of the WFD has been studied during activities of the European Concerted Action Harmoni-CA (www.harmoni-ca.info). The thesis closes with recommendations to improve social learning in practical river basin management.

京都大学 / 0048 / 新制・論文博士 / 博士(工学) / 乙第13278号 / 論工博第4181号 / 新制||工||1726(附属図書館) / (主査)教授 角 哲也, 教授 寶 馨, 准教授 Sameh Kantoush, 教授 立川 康人 / 学位規則第4条第2項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Dams and reservoirs with multiple purposes require effective management to fully realize their purposes and maximize efficiency. For instance, a reservoir intended mainly for the purposes of flood control and hydropower generation may result in a system with primary objectives that conflict with each other. This is because higher hydraulic heads are required to achieve the hydropower generation objective while relatively lower reservoir levels are required to fulfill flood control objectives. Protracted imbalances between these two could increase the susceptibility of the system to risks of water shortage or flood, depending on inflow volumes and operational policy effectiveness. The magnitudes of these risks can become even more pronounced when upstream use of the river is unregulated and uncoordinated so that upstream consumptions and releases are arbitrary. As a result, safe operational practices and risk management alternatives must be structured after an improved understanding of historical and anticipated inflows, actual and speculative upstream uses, and the overall hydrology of catchments upstream of the reservoir. One of such systems with an almost yearly occurrence of floods and shortages due to both natural and anthropogenic factors is the dual reservoir system of Kainji and Jebba in Nigeria. To analyze and manage these risks, a methodology that combines a stochastic and deterministic approach was employed. Using methods outlined by Box and Jenkins (1976), autoregressive integrated moving average (ARIMA) models were developed for forecasting Niger river inflows at Kainji reservoir based on twenty-seven-year-long historical inflow data (1970-1996). These were then validated using seven-year inflow records (1997-2003). The model with the best correlation was a seasonal multiplicative ARIMA (2,1,1)x(2,1,2)12 model. Supplementary iv validation of this model was done with discharge rating curves developed for the inlet of the reservoir using in situ inflows and satellite altimetry data. By comparing net inflow volumes with storage deficit, flood and shortage risk factors at the reservoir were determined based on (a) actual inflows, (b) forecasted inflows (up to 2015), and (c) simulated scenarios depicting undefined competitive upstream consumption. Calculated highrisk years matched actual flood years again suggesting the reliability of the model. Monte Carlo simulations were then used to prescribe safe outflows and storage allocations in order to reduce futuristic risk factors. The theoretical safety levels achieved indicated risk factors below threshold values and showed that this methodology is a powerful tool for estimating and managing flood and shortage risks in reservoirs with undefined competitive upstream consumption

Large river water basins play a critical role in the economic, health, and biodiversity conditions of a region. In some basins, such as the Zambezi River Basin, extreme weather events introduce cycles of drought and heavy rainfall that can have extreme impacts on local communities vulnerable to environmental shifts. Annual flood pulse dynamics drive ecological dynamics in the system. In the dry season, water dependent wildlife in northern Botswana concentrates along the Chobe River- Floodplains. Elephant concentration, in particular, is matched to surface water quality declines. These flood pulse events have been linked to diarrheal disease outbreaks in the local population, the magnitude of which is associated positively with flood height. Modeling these interactions can advance our ability to predict events and develop mitigation and prevention actions. However, many challenges hinder this development including availability of data in regions that lack resources and the difficulties in create models for such large basins that account for overland water movement. This thesis presents work focused on addressing these challenges. Chapter 2 reports the development of a freely available Large Basin Data Portal (LBDP) that can be used to identify and create critical inputs for hydrodynamic models. This portal was used to create a hydrological model of the Upper Zambezi River Basin model (Chapter 3), a hydrodynamic model of the one of the three subbasins of the Zambezi River. The model was used to calculate downstream river discharges entering the Chobe-Zambezi Floodplains based on upstream rain events. The Upper Zambezi River Basin model was integrated with another more detailed model of the Chobe- Zambezi Floodplains (Chapter 4) that is designed to model the Chobe River and flood water movement in the floodplains. The models were created using the set of MIKE modeling software. The models were used to study various scenarios including water reductions that might occur due to climate change or drought and water increase that might be associated with extreme weather events. / Doctor of Philosophy / River water plays a key role in the livelihood of people and wildlife especially in region of the world suffering chronic economic challenges. The areas surrounding the Zambezi River in Africa is home to one of the most diverse ecological systems in the world. Extreme weather conditions bring cycles of drought and flooding especially in the Upper Zambezi region where wildlife, including the largest population of African elephants in the world, move closer to the Chobe River, a tributary of the Zambezi River, seeking water in the dry seasons. This research is focused on building a set of tools and models to enable studying the linkage between these events and aid in predicting the extent of the floods in the Chobe River Floodplain system based on rainfall in the Angolan high lands and other landscape features. Understanding how these dynamics are linked and the outcome in the downstream system provides a lead time for potential action.

Tesis por compendio / [EN] New European policies established in the Blueprint (EC, 2012) propose the use of water accounting for the allocation and reservation of water resources. This course correction contrasts with the calculation of water balances that has been used since the last century in Spain for this purpose. According to the European Commission (EC, 2015) the difference between the two approaches is the inclusion of the economic component. This argument is indisputable, but it would also add that both "asset accounts" and the physical supply and use tables require a type of information that had not been considered until now. In view of this new challenge, the use of hydrological and water resources management models is essential. This thesis aims to implement a methodology for the transition between water balances and water accounting considering the special characteristics of the Mediterranean basin (with a high degree of regulation and the use of unconventional resources). In the same line, it raises the need for the definition of an indicator to assess the performance of a water resources system taking into consideration the origin of the water resources as a measure of the degree of stress suffered by the systems. This thesis is presented by publications and seeks to address the methodologies and indicators used to date in the planning and management of water resources. First, the state of the art is analyzed in the first publication of the thesis, as detailed in Annex 1. The second publication, analyzes the key elements for formulating water balances that will determine, to a large extent, results obtained, as detailed in Annex 2. The third publication, in Annex 3, tries to explain how in those basins where the use of water resources is close, or even higher, to their availability, the use of balances based solely on variables such as rainfall and temperature are not sufficient. And due to the high regulation of water resources they should also include the results of water management models. This approach contrasts with the proposals made by the countries of northern Europe focused mainly on hydrological models. In order to address the water accounting approach a pilot case located in the Andalusian Mediterranean basins was analysed. This work is presented in the fourth publication, reproduced in Annex 4. This initial analysis has served to highlight the need to develop a complementary software that allows unify the results of hydrological and water management models for calculating water accounts. The development of this software, which has been called AQUACCOUNTS, and its application to a general case with all the detail required in water resources planning has been published in the fifth article presented in Annex 5, taking the Júcar River Basin as a case study. From these results, a classification of water exploitation systems was carried out according to their degree of stress. These results were compared with the ones in Annex 2 which proposes the use of the indicator of exploitable water resources and which has been obtained with the traditional water balances approach. Finally, Annex 6 includes the last publication of this thesis focused on the effects of climate change in the Po River Basin (Italy) by using water accounting. This work has served to identify those key elements within the simulation models and opens the door to improve them within the approach proposed by the SEEA-W. This thesis aims to collaborate with those responsible for European policies in water resource planning for the application of those methodologies and tools appropriate to each territory. / [ES] Las nuevas políticas europeas establecidas en el Blueprint (EC, 2012) proponen el uso de la contabilidad del agua para la asignación y reserva de los recursos. Esta corrección del rumbo (cambio de paradigma) contrasta con el cálculo de balances que se ha venido utilizando desde el siglo pasado en España para dicho fin. Según la Comisión Europea (EC, 2015) la diferencia entre ambos planteamientos se halla en la inclusión de la componente económica. Este argumento es indiscutible, pero habría que añadir además que tanto las "asset accounts" como las tablas físicas de uso y suministro requieren un tipo de información que hasta ahora no se había considerado. A la vista de este nuevo reto, el uso de los modelos hidrológicos y de gestión de los recursos hídricos se hace imprescindible. Con esta tesis se pretende llevar a cabo una metodología que permita la transición entre los balances hídricos y las cuentas del agua teniendo en cuenta las especiales características de las cuencas mediterráneas (con un elevado grado de regulación y el uso de recursos no convencionales). En esta misma línea se plantea la definición de un indicador que trate de discutir el comportamiento conjunto de un sistema de recursos hídricos y que tenga en consideración el origen de los recursos empleados como medida del grado de estrés de los sistemas. Esta tesis se presenta por compendio de publicaciones y trata de abordar las metodologías e indicadores utilizados hasta la fecha en la planificación y gestión de los recursos hídricos. En primer lugar se analiza el estado del arte que constituye la primera publicación de la tesis, tal y como se detalla en el Anexo 1. La segunda publicación, analiza los elementos clave para la formulación de balances que determinarán, en gran medida, los resultados obtenidos, tal y como se detalla en el Anexo 2. La tercera publicación, en el Anexo 3, trata de explicar cómo en las cuencas donde el aprovechamiento de los recursos es cercano o incluso superior a su disponibilidad, el uso de los balances basados únicamente en variables como la precipitación y la temperatura no son suficientes, sino que debido a la alta regulación de los recursos debe recurrirse además a los modelos de gestión. Este planteamiento contrasta con las propuestas planteadas por los países del norte de Europa centrados principalmente en los modelos hidrológicos. Para abordar el tema se ha partido de un caso piloto localizado en las cuencas mediterráneas andaluzas. Este trabajo se presenta en la cuarta publicación, que se reproduce en el Anexo 4. A partir de este análisis inicial, se vio la necesidad de desarrollar un software complementario que permitiese unificar tanto la información de partida como los resultados de los modelos hidrológicos y de gestión para el cálculo de la contabilidad del agua. El desarrollo de este software, que ha sido denominado AQUACCOUNTS, y su aplicación a un caso general con todo el detalle requerido en planificación se ha publicado en el quinto artículo que se presenta en el Anexo 5, siendo la Demarcación Hidrográfica del Júcar el caso de estudio. A partir de los resultados obtenidos se ha llevado a cabo una clasificación de los sistemas de explotación según su grado de desarrollo comparándose con los resultados obtenidos en el Anexo 2 que propone el uso del indicador de recursos explotables y que se ha obtenido con las metodologías tradicionales de balances. Por último, el Anexo 6 recoge la última publicación de esta tesis en la que se analizan los efectos del cambio climático en la cuenca del río Po (Italia) mediante el uso de la contabilidad del agua. Este trabajo ha servido para identificar aquellos elementos clave dentro de los modelos de simulación y abre las puertas a una mejora de los mismos dentro del enfoque planteado por el SEEA-W. Esta tesis pretende colaborar con los responsables de las políticas europeas en materia de planificación para la apl / [CA] Les noves polítiques europees establides en el Blueprint (EC, 2012) proposen l'ús de la comptabilitat de l'aigua per a l'assignació i reserva dels recursos hídrics. Esta correcció del rumb (o canvi de paradigma) contrasta amb el càlcul de balanços que s'ha utilitzat des del segle passat a Espanya per a aquesta finalitat. Segons la Comissió Europea (EC, 2015) la diferència entre ambdós plantejaments es troba en la inclusió de la component econòmica. Este argument és indiscutible, però caldria afegir a més que tant les "asset accounts" com les taules físiques d'ús i subministrament requerixen un tipus d'informació que fins ara no s'havia considerat. A la vista d'este nou repte, l'ús dels models hidrològics i de gestió dels recursos hídrics es fa imprescindible. Amb esta tesi es pretén dur a terme una metodologia que permeta la transició entre els balanços hídrics i els comptes de l'aigua tenint en compte les especials característiques de les conques mediterrànies (amb un elevat grau de regulació i l'ús de recursos no convencionals). En esta mateixa línia es planteja la definició d'un indicador que tracte de discutir el comportament conjunt d'un sistema de recursos hídrics i que tinga en consideració l'origen dels recursos empleats com a mesura del grau d'estrés dels sistemes. Esta tesi es presenta per compendi de publicacions i tracta d'abordar les metodologies i indicadors utilitzats fins a la data en la planificació i gestió dels recursos hídrics. En primer lloc s'analitza l'estat de l'art que constituïx la primera publicació de la tesi, tal com es detalla en l'Annex 1. La segona publicació, analitza els elements clau per a la formulació de balanços que determinaran, en gran manera, els resultats obtinguts, tal com es detalla en l'Annex 2. La tercera publicació, en l'Annex 3, tracta d'explicar com en les conques on l'aprofitament dels recursos és pròxim o inclús superior a la seua disponibilitat, l'ús dels balanços basats únicament en variables com la precipitació i la temperatura no són suficients, sinó que a causa de l'alta regulació dels recursos ha de recórrer-se a més als models de gestió. Este plantejament contrasta amb les propostes plantejades pels països del nord d'Europa centrats principalment en el models hidrològics. Per a abordar el tema s'ha partit d'un cas pilot localitzat en les conques mediterrànies andaluses. Este treball es presenta en la quarta publicació, que es reproduïx en l'Annex 4. A partir d'aquest anàlisi inicial, es va veure la necessitat de desenrotllar una ferramenta complementaria que permetera unificar tant la informació de partida com els resultats dels models hidrològics i de gestió per al càlcul de la comptabilitat de l'aigua. El desenrotllament d'esta ferramenta, que ha sigut denominat AQUACCOUNTS, i la seua aplicació a un cas general amb tot el detall requerit en planificació s'ha publicat en el quint article que es presenta en l'Annex 5, sent la Demarcació Hidrogràfica del Xúquer el cas d'estudi. A partir dels resultats obtinguts s'ha dut a terme una classificació dels sistemes d'explotació segons el seu grau de desenrotllament comparant-se amb els resultats obtinguts en l'Annex 2 que proposa l'ús de l'indicador de recursos explotables i que s'ha obtingut amb les metodologies tradicionals de balanços. Finalment, l'Annex 6 arreplega l'última publicació d'esta tesi en què s'analitzen els efectes del canvi climàtic en la conca del riu Po (Itàlia) per mitjà de l'ús de la comptabilitat de l'aigua. Este treball ha servit per a identificar aquells elements clau dins dels models de simulació i obri les portes a una millora dels mateixos dins de l'enfocament plantejat pel SEEA-W. Esta tesi pretén col·laborar amb els responsables de les polítiques europees en matèria de planificació per a l'aplicació d'aquelles metodologies i ferramentes més adequades a cada territori. / Pedro Monzonís, M. (2016). Assessment of water exploitation indexes based on water accounting [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/71677 / Compendio

From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / Southwestern rivers are few in numbers and low in discharge. The physiographic and climatic reasons for this are discussed. To the east of the 100th meridian, rainfall is reliable and agriculture is stable; while to the west, there is a chronic deficit of water, droughts are frequent and lifestyles must be accordingly adjusted. Dam building results in greatly increased silting behind the dam in both the river and its tributaries and accelerated channel erosion below the dam. Total flow must also decrease due to withdrawals and increased evaporation from reservoirs. The correction of apparent errors in measuring the virgin flow of the Colorado River now indicates that this flow is about 15 maf/yr. Current legal allocations total 17.5 maf/yr of river water, including the central Arizona project (cap), which will withdraw 1.2 maf/yr. While the river is being dammed and overallocated beyond all reason, the water table is being mined at the alarming rate of 20 ft/yr. In central Arizona, it has dropped to about 250 ft below the surface, and even if all withdrawals ceased immediately, it would take many centuries of of desert rains before it would return to its former level of 50 ft. The cap water will cancel only about 1/2 of this overdraft annually. A glance at the phoenix area today shows that rain follows neither the farmers plow nor the subdividers bulldozer.

Numerous studies indicate that the hydrology of a river basin is influenced by Land Use Land Cover (LULC) and climate. LULC affects the quality and quantity of water resources through its influence on Evapotranspiration (ET) and initiation of surface runoff while climate affects the intensity and spatial distribution of rainfall and temperature which are major drivers of the hydrologic cycle. Literature reports several works on either the effect of changing LULC or climate on the hydrology. However, changes in LULC and climate occur simultaneously in reality. Thus, there is a need to perform an integrated impact assessment of such changes on the hydrological regime at a basin scale. In order to carry out the impact assessment, physically-based hydrologic models are often employed. The present study focuses on assessment of the effect of changing LULC and climate on the hydrology of the Upper Ganga basin (UGB), India, using the Variable Infiltration Capacity (VIC) hydrologic model. In order to obtain the changes that have occurred in the LULC of the basin over a time period, initially LULC analysis is carried out. For this purpose, high resolution multispectral satellite imageries from Landsat are procured for the years 1973, 1980, 2000 and 2011. The images are pre-processed to project them to a common projection system and are then co-registered. The processed images are used for classification into different land cover classes. This step requires training sites which are collected during the field visit as part of this work. The classified images, thus obtained are used to analyse temporal changes in LULC of the region. The results indicate an increase in crop land and urban area of the region by 47% and 122% respectively from 1973 to 2011. After initial decline in dense forest for the first three decades, an increase in the dense forest is observed between 2000- 2011 (from 11.44% to 14.8%). Scrub forest area and barren land are observed to decline in the study region by 62% and 96% respectively since 1973. The land cover information along with meteorological data and soil data are used to drive the VIC model to investigate the impact of LULC changes on streamflow and evapotranspiration (ET) components of hydrology in the UGB. For the simulation purpose, the entire basin is divided into three regions (1) upstream (with Bhimgodha as the outlet), (2) midstream (with Ankinghat as the outlet) and (3) downstream (with Allahabad as the outlet). The VIC model is calibrated and validated for all the three regions independently at monthly scale. Model performance is assessed based on the criterion of normalized root mean square error (NRMSE), coefficient of determination (R2) and Nash-Sutcliffe efficiency (NSE). It is observed that the model performed well with reasonable accuracy for upstream and midstream regions. In case of the downstream region, due to lack of observed discharge data, model performance could not be assessed. Hence, the simulations for the downstream region are performed using the calibrated model of the midstream region. The model outputs from the three regions are aggregated appropriately to generate the total hydrologic response of the UGB. Using the calibrated models for different region of the UGB, sensitivity analysis is performed by generating hydrologic scenarios corresponding to different land use (LU) and climate conditions. In order to investigate the impact of changing LU on hydrological variables, a scenario is generated in which climate is kept constant and LU is varied. Under this scenario, only the land cover related variables are altered in the model keeping the meteorological variables constant. Thus, the effect of LU change is segregated from the effect of climate. The results obtained from these simulations indicated that the change in LU significantly affects peak streamflow depth which is observed to be 77.58% more in August 2011 in comparison with the peak streamflow of August, 1973. Furthermore, ET is found to increase by 46.44% since 1973 across the entire basin. In order to assess the impact of changing climate on hydrological variables, a scenario is generated in which LU is kept constant and climate is varied from 1971-2005. Under this scenario, land cover related variables are kept constant in the model and meteorological variables are varied for different time periods. The results indicate decline in the simulated discharge for the years 1971, 1980, 1990, 2000 and 2005, which is supported by decline in observed annual rainfall for the respective years. Amongst 1971 and 2005, year 2005 received 26% less rainfall resulting in 35% less discharge. Furthermore, ET is observed to be negligibly affected. To understand the integrated impact of changing LU and climate on hydrological variables, a scenario is generated in which both climate and LU are altered. Based on the data available, three years (1973, 1980 and 2000) are considered for the simulations. Under this scenario, both land cover and meteorological variables are varied in the model. The results obtained showed that the discharge hydrograph for the year 1980 has significantly higher peak compared to the hydrographs of years 1973 and 2000. This could be due to the fact that the year 1980 received maximum rainfall amongst the three years considered for simulations. Although the basin received higher rainfall in the year 1980 compared to that in 2000, ET from the basin in the year 1980 is found to be 21% less than that of the year 2000. This could be attributed to the change in LU that occurred between the years 1980 and 2000. Amongst the years 1973 and 2000, there is not much difference in the observed rainfall but ET for the year 2000 is observed to be significantly higher than that of year 1973. It is concluded from the present study that in the UGB, changing LULC contributes significantly to the changes in peak discharge and ET while rainfall pattern considerably influences the runoff pattern of the region. Future work proposed includes assessment of hydrologic response of basin under future LULC and climate scenarios. Also the model efficiency can be assessed by performing hydrologic simulations at different grid sizes.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / James K. Koelliker / Small reservoirs catch and store water for long periods and they decrease streamflow and increase ground-water recharge. A field monitoring program provided the measured water depth for four years in several reservoirs in the Republican River Basin where there are concerns about their aggregate effects in the basin. The daily water budget operation for one reservoir was developed. Daily seepage rates were estimated by using precipitation, inflow and evaporation which was assumed equal to grass reference evapotranspiration (ET0), that average 120 to 150 cm/yr, along with the measured stage-storage and stage-surface area relationships. Two computer simulation modules, written in FORTRAN 95, were developed to estimate 1) overflow and gross seepage and 2) potential for ground-water recharge underneath the reservoir. Required daily input data are precipitation, ET0, and inflow from the watershed area. Required reservoir site characteristics include stage-storage and stage-surface area relationships, a standard seepage rate (S0) at 14 different levels in the reservoir, soil-water and plant-growth characteristics and a monthly crop-residue factor. The gross seepage module calculates water depth that determines daily overflow, the water-surface area for evaporation and the head of water on the 14 levels to cause seepage losses. If a level is not inundated, seepage is zero. If a level is inundated less than 0.3-m, S0 is used. When the water head (hL) on a level exceeds 0.3 m, the seepage rate (SL) is increased by, SL = S0 * (hL/0.3)0.25. This relationship was chosen after testing several exponent values between 0 and 1. The modules were calibrated on one reservoir and verified on two others in northwestern Kansas. Results showed runoff from the watersheds averaged about 1.2 to 1.6 cm/yr from the average annual precipitation of 46 to 62 cm. The three reservoirs reduced streamflow at the reservoir site by 74 to 97%, but 90 to 95% of the retained runoff was calculated to contribute to ground-water recharge. Several sensitivity analyses for model inputs were done. Results showed that, the ratio of the average annual inflow volume from the watershed area to the reservoir storage volume was the most sensitive input variable tested.