Demand Management Options Research Articles

Risk‐based water resources planning: Incorporating probabilistic nonstationary climate uncertainties

AbstractWe present a risk‐based approach for incorporating nonstationary probabilistic climate projections into long‐term water resources planning. The proposed methodology uses nonstationary synthetic time series of future climates obtained via a stochastic weather generator based on the UK Climate Projections (UKCP09) to construct a probability distribution of the frequency of water shortages in the future. The UKCP09 projections extend well beyond the range of current hydrological variability, providing the basis for testing the robustness of water resources management plans to future climate‐related uncertainties. The nonstationary nature of the projections combined with the stochastic simulation approach allows for extensive sampling of climatic variability conditioned on climate model outputs. The probability of exceeding planned frequencies of water shortages of varying severity (defined as Levels of Service for the water supply utility company) is used as a risk metric for water resources planning. Different sources of uncertainty, including demand‐side uncertainties, are considered simultaneously and their impact on the risk metric is evaluated. Supply‐side and demand‐side management strategies can be compared based on how cost‐effective they are at reducing risks to acceptable levels. A case study based on a water supply system in London (UK) is presented to illustrate the methodology. Results indicate an increase in the probability of exceeding the planned Levels of Service across the planning horizon. Under a 1% per annum population growth scenario, the probability of exceeding the planned Levels of Service is as high as 0.5 by 2040. The case study also illustrates how a combination of supply and demand management options may be required to reduce the risk of water shortages.

Estimation of single‐family residential irrigation demand management effectiveness

This article presents a systematic procedure to quantify savings potential of single‐family residential irrigation demand management strategies that can be used to evaluate the optimal blend of these strategies to achieve specified goals. Current irrigation practices, irrigable area, and irrigation application rate are derived for each single‐family residence based on parcel‐level tax assessor's data linked to customer‐level monthly water billing data. Water savings are calculated directly as the difference between current and proposed use after implementation of a management option for each residence. This information is used to develop performance functions that estimate total water savings as a function of the number of implementations for each residence. This procedure allows demand management options to be compared directly with other supply augmentation options when determining the optimal blend. Probabilistic models are derived from benchmark parcel‐level datasets for evaluation of other utilities where direct measurements are unavailable.

Least Economic Cost Regional Water Supply Planning – Optimising Infrastructure Investments and Demand Management for South East England’s 17.6 Million People

This paper presents a deterministic capacity expansion optimisation model designed for large regional or national water supply systems. The annual model selects, sizes and schedules new options to meet predicted demands at minimum cost over a multi-year time horizon. Options include: supply-side schemes, demand management (water conservation) measures and bulk transfers. The problem is formulated as a mixed integer linear programming (MILP) optimisation model. Capital, operating, carbon, social and environmental costs of proposed discrete schemes are considered. User-defined annual water saving profiles for demand management schemes are allowed. Multiple water demand scenarios are considered simultaneously to ensure the supply–demand balance is preserved across high demand conditions and that variable costs are accurately assessed. A wide range of supplementary constraints are formulated to consider the interdependencies between schemes (pre-requisite, mutual exclusivity, etc.). A two-step optimisation scheme is introduced to prevent the infeasibilities that inevitably appear in real applications. The model was developed for and used by the ‘Water Resources in the South East’ stakeholder group to select which of the 316 available supply schemes (including imports) and 511 demand management options (considering 272 interdependencies) are to be activated to serve the inhabitants of South East of England. Selected schemes are scheduled and sized over a 25 year planning horizon. The model shows demand management options can play a significant role in the region’s water supply and should be considered alongside new supplies and regional transfers. Considering demand management schemes reduced overall total discounted economic costs by 10 % and removed two large reservoirs from the least-cost plan. This case-study optimisation model was built using a generalised data management software platform and solved using a mixed integer linear programme.

A decision support tool for sustainable planning of urban water systems: Presenting the Dynamic Urban Water Simulation Model

Population growth, urbanisation and climate change represent significant pressures on urban water resources, requiring water managers to consider a wider array of management options that account for economic, social and environmental factors. The Dynamic Urban Water Simulation Model (DUWSiM) developed in this study links urban water balance concepts with the land use dynamics model MOLAND and the climate model LARS-WG, providing a platform for long term planning of urban water supply and water demand by analysing the effects of urbanisation scenarios and climatic changes on the urban water cycle. Based on potential urbanisation scenarios and their effects on a city's water cycle, DUWSiM provides the functionality for assessing the feasibility of centralised and decentralised water supply and water demand management options based on forecasted water demand, stormwater and wastewater generation, whole life cost and energy and potential for water recycling. DUWSiM has been tested using data from Dublin, the capital of Ireland, and it has been shown that the model is able to satisfactorily predict water demand and stormwater runoff.

Selecting Portfolios of Water Supply and Demand Management Strategies Under Uncertainty—Contrasting Economic Optimisation and ‘Robust Decision Making’ Approaches

Planning appropriate portfolios of new water supplies and demand management measures requires considering a wide array of options and their interactions over a largely unknown future. Various modelling-assisted approaches are available to help this planning process. This paper applies two such frameworks to the UK’s Thames water resource system and compares their methods and outputs: how they consider uncertainty, how they represent supply and demand management options, and what plans each recommends. The first method is the current England and Wales industry standard: annual least-cost capacity expansion optimisation over a 25 to 30 year time horizon considering capital, operating (fixed and variable), social and environmental costs. The second approach uses stochastic simulation and regret analysis to select a preferred alternative, then statistical cluster analysis to identify causes of system failure enabling further plan improvement. When applied iteratively with system planners this second approach is referred to as Robust Decision Making (RDM). The economic optimisation approach considers all plausible combinations of supply and conservation schemes and recommends the least-cost schedule of their implementation. Our RDM application considers a smaller number of options but makes a more detailed assessment of the effect of uncertainty (supply, demand and energy price uncertainty were considered) on multiple criteria of system performance. The simulation-based approach also enables more realistic interaction amongst supply and demand management schemes. Both approaches recommended different plans which we explain by discussing the benefits and limitations of each. Joint application is recommended to produce least-cost plans that are robust considering multiple criteria of performance across a wide range of futures.

Water Allocation of Yellow River Basin in Shanxi

Traditionally the water resources development activities in China were related to improving irrigated agriculture. The quantity based administrative allocation is the most common water allocation mode in China today. This paper analysis the water allocation of Yellow River basin in Shanxi province via technical methods. The objectives of water allocation in Yellow River basin are expressed in terms of priority settings, and different demand management options are also evaluated using the proposed methodology.

The Indus basin in the framework of current and future water resources management

Abstract. The Indus basin is one of the regions in the world that is faced with major challenges for its water sector, due to population growth, rapid urbanisation and industrialisation, environmental degradation, unregulated utilization of the resources, inefficient water use and poverty, all aggravated by climate change. The Indus Basin is shared by 4 countries – Pakistan, India, Afghanistan and China. With a current population of 237 million people which is projected to increase to 319 million in 2025 and 383 million in 2050, already today water resources are abstracted almost entirely (more than 95% for irrigation). Climate change will result in increased water availability in the short term. However in the long term water availability will decrease. Some current aspects in the basin need to be re-evaluated. During the past decades water abstractions – and especially groundwater extractions – have augmented continuously to support a rice-wheat system where rice is grown during the kharif (wet, summer) season (as well as sugar cane, cotton, maize and other crops) and wheat during the rabi (dry, winter) season. However, the sustainability of this system in its current form is questionable. Additional water for domestic and industrial purposes is required for the future and should be made available by a reduction in irrigation requirements. This paper gives a comprehensive listing and description of available options for current and future sustainable water resources management (WRM) within the basin. Sustainable WRM practices include both water supply management and water demand management options. Water supply management options include: (1) reservoir management as the basin is characterised by a strong seasonal behaviour in water availability (monsoon and meltwater) and water demands; (2) water quality conservation and investment in wastewater infrastructure; (3) the use of alternative water resources like the recycling of wastewater and desalination; (4) land use planning and soil conservation as well as flood management, with a focus on the reduction of erosion and resulting sedimentation as well as the restoration of ecosystem services like wetlands and natural floodplains. Water demand management options include: (1) the management of conjunctive use of surface and groundwater; as well as (2) the rehabilitation and modernization of existing infrastructure. Other demand management options are: (3) the increase of water productivity for agriculture; (4) crop planning and diversification including the critical assessment of agricultural export, especially (basmati) rice; (5) economic instruments and (6) changing food demand patterns and limiting post-harvest losses.

Water demand management optimization methodology

In contrast to traditional supply augmentation options, demand management options include specifying and/or replacing many small end uses that individually have a minimal effect on overall water use but that collectively can constitute significant aggregate reductions in demand. This article outlines a systematic procedure to quantify savings potential of single‐family residential indoor end‐use devices of a given utility and then select the optimal blend of retrofits to achieve a specified goal. Three steps are used to quantify savings potential of all end‐use devices. First, a utility's current end‐use fixture inventory and associated water use is estimated from parcel‐level data for each singlefamily residence. Second, customers are clustered into relatively homogeneous water use categories based on the age of the dwelling unit and the number of bathrooms. Third, water savings are calculated directly as the difference between current and proposed use after implementation of a management option for each group. This information is used to develop performance functions that estimate total water savings as a function of the number of fixture retrofits for each group.

Water scarcity and climatic change in India: the need for water demand and supply management

Against the discussion on the rationale and scope for water demand and supply management in India, this paper provides a brief overview of the status and effectiveness, as well as the technical, institutional and financial requirements of six demand management options (i.e. water pricing, water markets, water rights, energy regulations, water saving technologies, and user and community organizations) and one supply management option (involving the implementation of the National River Linking Project, NRLP). The paper then develops a framework that captures the analytics of water demand management in terms of both the impact pathways of and operational linkages among the options and their underlying institutions. Using this framework, the paper outlines a strategy for water demand management that can exploit well the inherent synergies among the options, and also align them well with the underlying institutional structure and its environment. Similarly, based on an analysis of the NRLP, the paper also indicates the strategy for implementing the NRLP and thereby promoting water supply management within the financial, institutional and political constraints. The paper concludes with the policy implications for water demand and supply management in India. Citation Saleth, R. M. (2011) Water scarcity and climatic change in India: the need for water demand and supply management. Hydrol. Sci. J. 56(4), 671–686.

Developing industrial water reuse synergies in Port Melbourne: cost effectiveness, barriers and opportunities

Urban water scarcity from ongoing drought and an increasing population are driving a range of water saving options to be explored in Melbourne (Australia). This paper assesses the cost effectiveness of five water treatment and industrial reuse options in the Fishermans Bend industrial area at Port Melbourne. In consultation with industrial stakeholders and the local water utility, the study design began by identifying potential water sources and sinks in the area. Treatment technologies for each option – using a combination of membrane bioreactors (MBR) and in some cases reverse osmosis (RO) technologies – were developed. In evaluating the potential for future implementation, the cost effectiveness ($/kiloLitre) was assessed relative to water supply augmentation and water demand management options available in Melbourne. Additionally, the opportunities and barriers for option implementation in Port Melbourne were contrasted with the Kwinana Industrial Area, Western Australia where many regional synergy projects have been undertaken. This research identifies that the future implementation of industrial ecology opportunities requires strong and ongoing stakeholder involvement as described in this paper.

Urban Water Management Using Fuzzy-Probabilistic Multi-Objective Programming with Dynamic Efficiency

This paper introduces a new multi-objective optimization model for integrated urban water management. The model, based on compromise programming, is applied for the case of Tabriz city in Iran. The water demand of this city is rapidly growing and because of the limited resources, water supply is now more vulnerable to any mismanagement. Therefore the model attempts to optimize the water supply plan of city concerning three main objectives of maximizing the water supply, minimizing the cost and minimizing the environmental hazards. Due to the vagueness in defining the first objective, it is modeled by using the fuzzy set theory. Further, the uncertainty in satisfying some constraints is tackled by using the chance constraint approach. The decision variables are the extent of water withdrawal from the city aquifer, three different water transfer schemes and also the extent of demand management by leaks detection and pipes rehabilitation. Then the fuzzy-probabilistic multi-objective model is solved by considering the new idea of dynamic efficiency in the utility of decision maker and the results provide the optimum water supply in the planning horizon. The model results in robust solutions in which the demand management option dominates the new water transfer. Implementing the results of this model supports the environmental conservation and sustainable development.

Promoting irrigation demand management in India: options, linkages and strategy

Against the backdrop of a discussion on the rationale, logic and scope of irrigation demand management in India, this paper provides a brief overview of the status, effectiveness and technical and institutional requirements of six demand management options, that is, water pricing, water markets, water rights, energy regulations, water saving technologies and user organizations. The paper then develops a framework that captures the analytics of irrigation demand management in terms of both the impact pathways of and the operational linkages between the options and their underlying institutions. Using this framework, the paper also outlines a strategy for irrigation demand management that can exploit the inherent synergies between the options and align them well with the underlying institutional structure and its environment. After discussing how such a strategy can be effectively promoted within the institutional and political constraints facing countries such as India, the paper concludes with the policy implications of irrigation demand management.

The challenge of water conservation and water demand management for irrigated agriculture in South Africa

More than 50% of South Africa's catchments are deemed to be over-allocated. The challenge is to find ways to bring the over-allocated catchments back into balance in a manner that does not shock the socio-economic fabric of the country. The logical starting point is to try to do better with less water. In this article, water conservation and water demand management (WC & WDM) options are discussed, with particular reference to the irrigation sector as it is the dominant water user in South Africa. The concept of banking water, which incentivizes irrigators to become more water use efficient, is also explored.

Assessment of rainwater use and greywater reuse in high-rise buildings in a brownfield site

This study describes the use of rainwater and greywater (originated from bathroom only) for provision of non-contact indoor and outdoor use in high-rise buildings. A brownfield development site in Box Hill suburb of Melbourne was selected as case study site for this investigation. The performance of alternative servicing options was compared with conventional water supply, stormwater and wastewater servicing. A water balance model UVQ (Urban Volume and Quality) was applied to determine storage capacities and to evaluate the percentage reduction in water supplying, stormwater run-off and wastewater disposal, as well as volumes of rainwater use and greywater reuse. In this study, the impact of variation in collection area (600 m(2) and 900 m(2)) and appliance discharge volumes was examined. A number of demand management options were also investigated. The results of this study indicate greywater reuse is more suited than rainwater use for this development because of the steady, constant supply of greywater compared to the highly fluctuating, storm-event supply of rainwater and the high population density creating comparatively large volumes of greywater.

Identification of opportunities to improve efficiency by water consumption assessment

Characterization of water demand can be of great value for the management of water supply systems. Especially when water resources are limited, permanently or seasonally, the identification of the types of consumers and their characteristics is essential to identify opportunities to promote efficiency and demand management options. For each customer category, information to be obtained includes individual uses, typical daily usage patterns (average and dispersion), specific characteristics and magnitude. Knowledge and systematization of water uses also provide data to improve water balance and thus allow reducing uncertainty in estimation of losses. A study carried out in Algarve, a region where stress on water supply resources has been increasing, is presented aiming at better characterization of water consumption in the region to improve response both to normal and emergency situations.

Managing irrigation demand to improve seasonality of river flows

AbstractHuman interventions often lead to unsustainable river systems. There is always a trade‐off between level of socio‐economic gains from consumptive use in the river system and the need to maintain the natural seasonality of river flows supporting the ecosystem function. In the case of the Murrumbidgee River, Australia, irrigation demand is concentrated in the summer season while natural inflows to the river occur during the winter season. The summer‐dominated irrigation water demand has created environmental and supply problems by altering the natural flow regime. This paper presents a hydrologic assessment of a range of irrigation demand management options for improving the natural seasonality of the river flow. Among the possible alternatives, change of cropping pattern by achieving a better mix of summer and winter crops is recommended as the most feasible alternative, which can also save up to 211 million m3 of water yearly. This water can then be released during the winter time to augment the environmental flows of the river. Other irrigation demand management options explored in this paper include aquifer storage and recovery, on‐farm and off‐farm water savings and construction of intermediate surface water storages. Copyright © 2008 John Wiley & Sons, Ltd.

Assessing integrated water management options for urban developments – Canberra case study

Urban water services in the Australian Capital Territory (ACT) are currently provided through conventional centralised systems, involving large-scale water distribution, wastewater collection, water and wastewater treatment. A study was conducted to assist Environment ACT in setting broad policies for future water services in Canberra. The current paper presents the outcomes of a study examining the effects of various water servicing options on water resources and the environment, for two townships in Canberra, one existing and one greenfield site. Three modelling tools were used to predict the effects of various alternative water servicing scenarios, including demand management options, rainwater tanks, greywater use, on-site detention tanks, gross pollutant traps, swales and ponds. The results show that potable water reductions are best achieved by demand management tools or a combination of greywater and rainwater use for existing suburbs, while third pipe systems are preferred for greenfield sites. For this specific climatic region and end use demands, modelling predicted increased water savings from raintanks compared to greywater systems alone, with raintanks providing the additional benefit of reduced peak stormwater flows at the allotment scale. Rainwater and stormwater reuse from stormwater ponds within the catchments was found to provide the highest reduction in nutrient discharge from the case study areas. Environment ACT amended planning controls to facilitate installation of raintanks and greywater systems, and commenced a Government funded rebate scheme for raintanks as a result of this study.

Dealing with Closed Basins: The Case of the Lower Jordan River Basin

During the past 50 years, the Lower Jordan River basin experienced a rapid and comprehensive process of development of its rare water resources. This led to its progressive closure; almost no water is left that can be mobilized and used while demand, notably in urban areas, keeps increasing. Despite the need to consider demand management options to alleviate the Jordanian water crisis, the potential of these options appears limited in the mid-term; the growing demand of the population and the sustaining of agriculture are unlikely to be met without supply augmentation measures which will reopen the basin.

Trade-off analysis for restoring environmental flows through irrigation demand management

The aim of this paper is to evaluate economic trade-offs of introducing irrigation demand management measures to modify river flows in order to mimic natural flow variations in the rivers. A number of irrigation demand management options were identified through rigorous discussions with the key stakeholder groups in the Murrumbidgee Catchment. The impacts of alternative demand management options are presented in terms of a matrix of economic costs and associated water savings. The modelling results revealed that 10–15% of peak water use during summer can be reduced from the average total annual water use of 1400 GL. This may result in reduced economic return or require private and public investments in the form of on-farm water saving technologies, canal lining or construction of en-route storage. However, if we value the saved water at current market prices, then benefits are expected to be higher than the costs involved. Among all other options, spreading water use over summer and winter season through new crop mixes promises to be the most cost-effective irrigation demand management option for improving seasonality of flow in the rivers. The study also found that increasing on-farm water use efficiency to reduce peak water use is in the farmer’s economic self-interest through reduced water inputs per unit of production; it will also help increase streamflows if suitable mechanisms for securing environmental flows can be implemented.

Identification of opportunities to improve efficiency by water consumption assessment

Characterization of water demand can be of large value for the management of water supply systems. Especially when water resources are limited, permanently or seasonally, the identification of the types of consumers and its characteristics are essential to identify opportunities to promote efficiency and demand management options. For each customer category, information to be obtained includes individual uses, typical daily usage patterns (average and dispersion), specific characteristics and magnitude. Knowledge and systematization of water uses also provides data to improve water balance and thus allows reducing uncertainty in losses estimation. In this paper, a study carried out in Algarve, a region where stress on water supply resources has been increasing, is presented aiming at better characterise water consumption in the region to improve response both to normal and in emergency situations.