Water Allocation Rules Research Articles

HESS Opinions: The unsustainable use of groundwater conceals a “Day Zero”

Abstract. Water scarcity is a pressing global issue driven by increasing water demands and changing climate conditions. Based on novel estimates of water availability and water use in Chile, we examine the challenges and risks associated with groundwater (GW) withdrawals in the country's central-north region (27–35° S), where extreme water stress conditions prevail. As total water use within a basin approaches the renewable freshwater resources, the dependence on GW reserves intensifies in unsustainable ways. This overuse has consequences that extend beyond mere resource depletion, manifesting into environmental degradation, societal conflict, and economic costs. We argue that the “Day Zero” scenario, often concealed by the uncertain attributes of GW resources, calls for a reconsideration of water allocation rules and a broader recognition of the long-term implications of unsustainable GW use. Our results offer insights for regions worldwide facing similar water scarcity challenges and emphasize the importance of proactive and sustainable water management strategies.

Assessment of water demand reliability using SWAT and RIBASIM models with respect to climate change and operational water projects

Reliability assessment in the allocation of water resources under the changing climate condition has invaluable importance in planning the water demand at the basin scale. This study details an integrated framework for evaluation of the reliability between water supply and demand under climate change scenarios in the Zarrineh Rood River basin in the northwest of Iran. Initially, recorded climatic data in six synoptic stations are downscaled and projected for the period 2020–2040 based on the 14 GCMs using the LARS-WG method. Afterwards, the SWAT model is used to simulate the basin hydrology with consideration to the baseline and future climate periods at six hydrometric stations. Finally, the available water is allocated using the RIBASIM model based on the current supply-demand chain and predefined governmental water allocation rules for different sectors. Results showed that under climate change, the total runoff of the basin and the entrance catchments to the Zarrineh Rood River dam would decrease about 8% and 28%, respectively. The reliability of the water supply for joint drinking-industrial and agricultural demands would also decrease from 96.4% to 93.4%, and 90.2–89.5%, respectively. As such, the average annual streamflow from the Zarrineh Rood River ending to Lake Urmia will reduce by 10% if the operational water projects remain active.

A water resource simulator in Python

A new generalised water resource network modelling Python library, Pywr, is presented. Given hydrological inflows, Pywr simulates customisable water allocation and operation rules throughout complex multi-purpose managed water systems at each user-defined time-step. The model uses a low-level interface to existing linear programming solvers for fast priority-based optimisation-driven simulation. The library uses an object based system for users to provide input data and record simulation outputs. A novel multi-scenario simulation method provides an almost 4-fold improvement in model run-times and supports calculating robustness metrics across scenarios. A flexible interface to specify multi-objective optimisation formulations as part of a model’s input file is included. These features enable analysts to apply advanced water planning approaches, such as robust decision making and robust optimisation, to real systems. The library is available under the GPLv3 open source licence, includes several examples and a regression test suite.

Making concrete flexible: Adapting the operating rules of the Cantareira water system (São Paulo, Brazil)

The Cantareira system is a network of reservoirs located in the inland region of São Paulo State. In 1974 it started operating to bring water from a sparsely populated region – the headwaters of the Piracicaba, Capivari, and Jundiaí (PCJ) rivers – to a densely inhabited and fast-growing region – the São Paulo Metropolitan Region (SPMR). Since then, the operating rules of the Cantareira system have been revised and renegotiated twice, in 2004 and 2017, to better respond to technical challenges and changing political, legal and institutional conditions. The article presents the evolution of the water allocation rules, its drivers and how it has reflected in the regional sharing of the benefits provided by the water transfer. This case showcases that also infrastructure-based allocations can be dynamic and adaptable to face new challenges, but the room for maneuver for changing the configuration of benefit sharing is limited.

A Global Analysis of Future Water Deficit Based On Different Allocation Mechanisms

AbstractFreshwater scarcity is already an urgent problem in some areas but may increase significantly in the future. To assess future developments, we need to understand how future population growth, agricultural production patterns, energy use, economic development, and climate change may impact the global freshwater cycle. Integrated models provide opportunities for quantitative assessment. In this paper, we further integrate models of hydrology and economics, using the models IMAGE and LPJmL, with explicit accounting for (1) electricity, industry, and municipal and irrigation water use; (2) intersectoral water allocation rules at the 0.5° × 0.5°grid scale; and (3) withdrawal, consumption, and return flows. With the integration between hydrology and economy we are able to understand competition dynamics between the different freshwater users at the basin and grid scale. We run model projections for three Shared Socioeconomic Pathways (SSPs), more efficient water use, and no expansion of irrigated areas to understand the competition dynamics of these different allocation mechanisms. We conclude that (1) global water withdrawal is projected to increase by 12% in SSP‐1, 26% in SSP‐2, and 29% in SSP‐3 during 2010–2050; (2) water deficits (demand minus allocated water) for nonagricultural uses are small in 2010 but become significant around 2050; (3) interannual variability of precipitation results in variability of water deficits; (4) water use efficiency improvements reduce water withdrawal but have little impact on water deficits; and (5) priority rules at the local level have a large effect on water deficits, whereas limiting the expansion of irrigation has virtually no effect.

Minimization of water pumps' electricity usage: A hybrid approach of regression models with optimization

Due to pervasive deployment of electricity-propelled water-pumps, water distribution systems (WDSs) are energy-intensive technologies which are largely operated and controlled by engineers based on their judgments and discretions. Hence energy efficiency in the water sector is a serious concern. To this end, this study is dedicated to the optimal operation of the WDS which is articulated as minimization of the pumps’ energy consumption while maintaining flow, pressure, and tank water levels at a minimum level, also known as pump scheduling problem (PSP). This problem is proved to be NP-hard (i.e. a difficult problem computationally). We therefore develop a hybrid methodology incorporating machine-learning techniques as well as optimization methods to address real-life and large-sized WDSs. Other main contributions of this research are (i) in addition to fixed-speed pumps, the variable-speed pumps are optimally controlled, (ii) and operational rules such as water allocation rules can also be explicitly considered in the methodology. This methodology is tested using a large dataset in which the results are found to be highly promising. This methodology has been coded as a user-friendly software composed of MS-Excel (as a user interface), MS-Access (a database), MATLAB (for machine-learning), GAMS (with CPLEX solver for solving optimization problem) and EPANET (to solve hydraulic models).

Simulating Water Allocation and Cropping Decisions in Yemen’s Abyan Delta Spate Irrigation System

Agriculture employs more Yemenis than any other sector and spate irrigation is the largest source of irrigation water. Spate irrigation however is growing increasingly difficult to sustain in many areas due to water scarcity and unclear sharing of water amongst users. In some areas of Yemen, there are no institutionalised water allocation rules which can lead to water related disputes. Here, we propose a proof-of-concept model to evaluate the impacts of different water allocation patterns to assist in devising allocation rules. The integrated model links simple wadi flow, diversion, and soil moisture-yield simulators to a crop decision model to evaluate impacts of different water allocation rules and their possible implications on local agriculture using preliminary literature data. The crop choice model is an agricultural production model of irrigation command areas where the timing, irrigated area and crop mix is decided each month based on current conditions and expected allocations. The model is applied to Yemen’s Abyan Delta, which has the potential to be the most agriculturally productive region in the country. The water allocation scenarios analysed include upstream priority, downstream priority, equal priority (equal sharing of water shortages), and a user-defined mixed priority that gives precedence to different locations based on the season. Once water is distributed according to one of these allocation patterns, the model determines the profit-maximising plant date and crop selection for 18 irrigated command areas. This aims to estimate the impacts different water allocation strategies could have on livelihoods. Initial results show an equal priority allocation is the most equitable and efficient, with 8% more net benefits than an upstream scenario, 10% more net benefits than a downstream scenario, and 25% more net benefits than a mixed priority.

Optimization of equitable irrigation water delivery for a large-scale rice irrigation scheme

Equitable water allocation is essential in an irrigation scheme for obtaining potential crop yields from the entire scheme, especially when water supply is inadequate. An optimization model achieved this goal by coupling an optimal water allocation model with available water supply and irrigation water demand for a river-fed rice irrigation system in Malaysia. This model consists of a paddy field water balance module and an optimization module. The outputs from the module are daily irrigation demand and surface runoff, if there is any. The optimization module consists of an objective function, which minimizes water shortage across the scheme area while maintaining equity in water allocation. This model performs optimization subject to several system constraints, and the decision variable of the model is daily releases or supply to the tertiary canals. Performance of this model remained unaffected under different water supply conditions, and the optimization model reliably examined the effects of alternate water allocation and management rules with field information. It improves efficiency and equity in water allocation with respect to crop growth stages and water shortages rather than simply cutting irrigation supply on a proportional basis to overcome water shortages. Keywords: irrigation, optimization, simulation, equitable deliveries, rice DOI: 10.25165/j.ijabe.20181105.3536 Citation: Rowshon M K, Iqbal M, Mojid M A, Amin M S M, Lai S H. Optimization of equitable irrigation water delivery for a large-scale rice irrigation scheme. Int J Agric & Biol Eng, 2018; 11(5): 160–166.

Water security: stakeholders’ arena in the Awash River Basin of Ethiopia

Water insecurity is a growing challenge manifested from global to local scales. This paper examines stakeholders and their roles to tackle the challenges of water insecurity in the Awash basin of Ethiopia. The empirical evidence is based on stakeholder analysis employing key informant interviews with water experts using snowball techniques, focused group discussions with water user associations, and local communities. Moreover, secondary data sources were used to supplement the field data. The study is informed by Institution of Sustainability (IoS) to understand stakeholders’ arena in water security goal. The government institutions, private institutions, external bodies, and the local community were the key stakeholders. They engaged in water use, allocation, distribution, policy making, advocacy, and setting rules and regulations, development and management, and financing of water sector–water transaction processes. Nevertheless, it was found out that the stakeholders are not acting synergistically and coordinated to tackle the anthropogenic and natural factors affecting water quality, quantity, and access to safe water on a sustainable basis. Poor coordination fragmented the endeavours of various stakeholders and constrained effective participation. Power asymmetry among the actors limited their collaboration. In addition, there is little enforcement of water rules and regulations to surmount such challenges. Given these challenges, the dire water insecurity is a conspicuous manifestation in the basin. The potential of enforcing existing laws, engagement of pertinent stakeholders, as well as coordinating the action of these actors must be exploited to achieve sustainable water resources management and thereby water security. The political commitment is a sine qua non in the entire endeavour.

Adapting to Variable Water Supply in the Truckee-Carson River System, Western USA

In snow-fed inland river systems in the western United States, water supply depends upon timing, form, and amount of precipitation. In recent years, this region has experienced unprecedented drought conditions due to decreased snowpack, exacerbated by exceptionally warmer winter temperatures averaging 3–4 °C above normal. In the snow-fed Truckee-Carson River System, two sets of interviews were conducted as part of a larger collaborative modeling case study with local water managers to examine local adaptation to current drought conditions. A comparative analysis of these primary qualitative data, collected during the fourth and fifth consecutive years of continued warmer drought conditions, identifies shifts in adaptation strategies and emergent adaptation barriers. That is, under continuous exposure to climate stressors, managers shifted their adaptation focus from short-term efforts to manage water demand toward long-term efforts to enhance water supply. Managers described the need to: improve forecasts and scientific assessments of snowmelt timing, groundwater levels, and soil moisture content; increase flexibility of prior appropriation water allocation rules based on historical snowpack and streamflow timing; and foster collaboration and communication among water managers across the river system. While water scarcity and insufficient water delivery infrastructure remain significant impediments in this arid region, climate uncertainty emerged as a barrier surrounding adaptation to variable water supply. Existing prior appropriation based water institutions were also described as an adaptation barrier, meriting objective evaluation to assess how to best modify these historical institutions to support dynamic adaptation to climate-induced water supply variability. This study contributes to a growing body of research that assesses drought adaptation in snow-fed inland river systems, and contributes a unique report concerning how adaptation strategies and barriers encountered by local water managers change over time under continuous exposure to climate stressors. These locally identified adaptation strategies forward a larger collaborative modeling case study by informing alternative water management scenarios simulated through a suite of hydrologic and operations models tailored to this river system.

Efficiency and acceptance of new water allocation rules - The case of an agricultural water users association

Water scarcity is one of the major environmental problems in Southern Europe. High levels of water stress and increasing frequency of droughts, along with a greater environmental protection, make it necessary to design water management strategies that are allocative efficient and balance supply and demand. When functioning markets cannot be developed, the allocation rules proposed in the literature of social choice have been recognized as a suitable alternative. However, the application of new water allocation rules can be impaired by a lack of acceptance and implementation problems. This paper examines these obstacles for the case of an agricultural water users association (WUA), situated in the basin of the River Ebro, in relation to the governance structure and collective decision rule of the WUA. It analyzes the extent to which the gains and losses of the farmers affect their acceptance, and examines conditions for building agreements with side payments that provide incentives for the majority of the farmers to form part of a possible agreement. The results show that the uniform and sequential rules improve the allocative efficiency under normal conditions compared to the status quo and the sequential rule even in the case of droughts. In the presence of side payments this rule is likely to be accepted and has only an insignificant impact on distributional inequality.

Allocating Water under Bankruptcy Scenario

Most of the transboundary river basins are contested due to the overlapping water demands of their riparian countries. Hence, these border crossing river basins are under immense pressure from the rising water demand. Thus, most of these essential fresh water resources could face water bankruptcy scenario in the future. The Nile river basin is one of these contested river basins. The demand for the river’s water is rising rapidly. Research studies indicated that the river basin could become water bankrupt in the near future. In this article the authors applied the classical bankruptcy water allocation rules for allocating the predicted available water of the river basin. In addition, the authors proposed an innovative way of accounting the water contribution of riparian states and also a mechanism for weighing the water deficit allotted to them. Generally, the authors hope that this article shades some light on allocation of water under water scarcity in the Nile river basin and in other border crossing river basins which could help for avoiding water conflicts and ensuring the sustainability of these crucial freshwater resources.

Farm-based cropping pattern optimization and conjunctive use planning using piece-wise genetic algorithm (PWGA): a case study

So far, several agro-economic optimization models have been developed in order to deal with agricultural water resources planning and management, among which the cropping pattern and water allocation optimization models are of significant importance. However, these models usually consider the land as a plain entirety and fail to account for a number of important contributing factors, including the private ownership of agricultural lands and the unique characteristics of each land parcel. Hence, the solutions provided by these models are not fully applicable in real-world and are only meant to help the decision-maker in analyses. In the present study, a new model is developed in order to incorporate farm-level data, and to propose optimal cropping pattern and conjunctive use decisions at farm level. Furthermore, a modified genetic algorithm has been developed by piecewise reorganization of chromosome structure, namely piecewise genetic algorithm (PWGA), and is presented in order to tackle the nonlinearity and the high number of variables involved in the model. A URM-based groundwater model is also coupled with PWGA in order to improve the computational efficiency of the framework. The proposed model is then run for various scenarios and the results are compared with those of the general approaches. The results of this study demonstrate that the general plain-level models tend to overestimate the expected net benefits. Moreover, the proposed model is able to optimize the cropping pattern and water allocation rules over the area while supporting each land parcel with appropriate decisions.

Water governance and adaptation to climate change in the Indus River Basin

Summary Conflicting approaches to water governance at multiple scales within large international river basins may have detrimental effects on the productivity of water resources and consequently the economic activities of the basin. In the Indus River Basin, local scale water productivity decisions are affected by international and intra-national scale water governance. Water availability and productivity is modulated by the Indus Waters Treaty between India and Pakistan, and within Pakistan by the agreements governing water allocation between and within provinces. Much of the literature on governance at multiple scales in the Indus basin, and others, has employed qualitative methods of institutional analysis. This paper extends that approach with quantitative modeling of surface water allocation rules at multiple scales and the consequent economic impact on water use and productivity in the Indus River of Pakistan. The effects of the existing water allocation mechanisms on the ability to adapt to possible future climate conditions are examined. The study is conducted using the Indus Basin Model Revised – Multi-Year (IBMR–MY), a hydro-agro-economic model of the Indus River within Pakistan that simulates river and canal flows, groundwater pumping, water use and economic activities with a distributed, partial equilibrium model of the local scale agro-economic activities in the basin. Results suggest that without changes in response to changing conditions, the current governance mechanisms impede the provinces’ ability to adapt to changing climate conditions, in ways that are significant, inflicting economic costs under both high and low flow conditions. However surface water allocation between the provinces does not appear to hinder adaptation. The greatest gains for economic water allocation are achieved at the sub-provincial level. The results imply that adaptive mechanisms for water allocation that allow response to changing climate conditions within provinces may be a promising adaptive response in the Indus Basin.

Inequality and rules in the governance of water resources

This paper considers two types of farmer, with unequal land endowments, who voluntarily contribute to a joint project for the maintenance of an irrigation network. The collective output (water) is distributed according to some allocation rule and used by each farmer in combination with land to produce a final good. The analysis shows that the initial degree of inequality affects the allocation rule that maximises the amount of water collectively provided. Specifically, two forces act in opposite directions. The first ‘effort-augmenting’ force pushes the distribution of water towards the agent with the higher return to water in the attempt to maximise the aggregate level of effort. This is the prominent force when efforts are highly substitute. If efforts display some degree of complementarity, the effort mix, alongside with aggregate effort, becomes important. A second ‘effort-mix’ force then emerges, that favours more egalitarian or even progressive water allocation rules.

Determination of cost coefficients of a priority-based water allocation linear programming model – a network flow approach

Abstract. This paper presents a method to establish the objective function of a network flow programming model for simulating river–reservoir system operations and associated water allocation, with an emphasis on situations when the links other than demand or storage have to be assigned with nonzero cost coefficients. The method preserves the priorities defined by rule curves of reservoir, operational preferences for conveying water, allocation of storage among multiple reservoirs, and transbasin water diversions. Path enumeration analysis transforms these water allocation rules into linear constraints that can be solved to determine link cost coefficients. An approach to prune the original system into a reduced network is proposed to establish the precise constraints of nonzero cost coefficients, which can then be efficiently solved. The cost coefficients for the water allocation in the Feitsui and Shihmen reservoirs' joint operating system of northern Taiwan was adequately assigned by the proposed method. This case study demonstrates how practitioners can correctly utilize network-flow-based models to allocate water supply throughout complex systems that are subject to strict operating rules.

A negotiation support system for disputes between Iraq and Turkey over the Tigris-Euphrates basin

• A NSS for disputes between Iraq and Turkey over the Tigris-Euphrates basin. • A NSS based on context suggested and UN Convention principles recognised by Turkey. • Negotiation outcomes arising from dynamic interactions between the parties. • An application of the NSS based on plausible and reasonable, but tentative, data. • Contextual water allocation rules in the negotiation and cooperation scenarios. This paper describes a flexible prototype negotiation support system (NSS), to be used in a participatory context, based on the negotiation setting that was suggested by Turkey: bilateral negotiations between Turkey and Iraq, annual analysis, the assumption that Iraq and Syria have no inherent water rights, differences in water entitlements or needs are neglected, analysis restricted to the Tigris-Euphrates basin, current irrigation technologies in Turkey and Iraq, and negotiations on water quantity and quality that account for national dam construction plans. The analysis is based on all principles of the 1997 UN Convention that are recognised by Turkey: net benefits defined at a basin level, equitable use, non-significant harm, maintenance of water quality. The goal is to achieve a balance of interests among the parties that combines analysis of the quantity and quality of water and the net benefits. The negotiation outcomes arise from simulated dynamic interactions between the parties. We demonstrate an application of the NSS based on plausible and reasonable, but tentative, data to provide insights into water allocation rules, side-payments, water requirements of the two parties, and cooperation. Allocations should meet Iraqi non-significant harm and equitable use constraints and allocate the remaining water to Turkey for agricultural use in the feasible negotiation scenario, whereas allocations should meet Turkish maximum agricultural water demands and allocate the remaining water to Iraq for agricultural use in the unlikely cooperation scenario.

Equity in bulk water allocation: the case of the Mahaweli Ganga Development Project in Sri Lanka

This article evaluates the equity performance of bulk water allocation as an irrigation management strategy in the Mahaweli Ganga Development Project, Sri Lanka. Through semi-structured interviews with farmers and irrigation officials, the study collected local perceptions using seven indicators: water rights; decision-making process; contribution of resources for irrigation maintenance; water allocation rules; actual water distribution; information sharing; and conflict resolution. The results highlight gaps in the institution such as the need to enhance the water rights of landless farmers, further encourage crop diversification, increase transparency in decision making, instil a risk-management approach, and strengthen accountability.

Optimal water and waste load allocation in reservoir–river systems: a case study

In this paper, a new methodology is developed for optimization of water and waste load allocation in reservoir–river systems considering the existing uncertainties in reservoir inflow, waste loads and water demands. A stochastic dynamic programming (SDP) model is used to optimize reservoir operation considering the inflow uncertainty, and another model called PSO-SA is developed and linked with the SDP model for optimizing water and waste load allocation in downstream river. In the PSO-SA model, a particle swarm optimization technique with a dynamic penalty function for handling the constraints is used to optimize water and waste load allocation policies. Also, a simulated annealing technique is utilized for determining the upper and lower bounds of constraints and objective function considering the existing uncertainties. As the proposed water and waste load allocation model has a considerable run-time, some powerful soft computing techniques, namely, Regression tree Induction (named M5P), fuzzy K-nearest neighbor, Bayesian network, support vector regression and an adaptive neuro-fuzzy inference system, are trained and validated using the results of the proposed methodology to develop real-time water and waste load allocation rules. To examine the efficiency and applicability of the methodology, it is applied to the Dez reservoir–river system in the south-western part of Iran.

Obtaining natural-like flow releases in diverted river reaches from simple riparian benefit economic models

We propose a theoretical river modeling framework for generating variable flow patterns in diverted-streams (i.e., no reservoir). Using a simple economic model and the principle of equal marginal utility in an inverse fashion we first quantify the benefit of the water that goes to the environment in relation to that of the anthropic activity. Then, we obtain exact expressions for optimal water allocation rules between the two competing uses, as well as the related statistical distributions. These rules are applied using both synthetic and observed streamflow data, to demonstrate that this approach may be useful in 1) generating more natural flow patterns in the river reach downstream of the diversion, thus reducing the ecodeficit; 2) obtaining a more enlightened economic interpretation of Minimum Flow Release (MFR) strategies, and; 3) comparing the long-term costs and benefits of variable versus MFR policies and showing the greater ecological sustainability of this new approach.