Demand Management Options Research Articles

Trade-offs between water security and energy use: Lifecycle energy of water supply options in Paju, Korea

Despite net zero movement in Korea's water sector, comprehensive assessments of water-related energy in the region are lacking. Focusing on a water-stressed city with diversified water sourcing, this study evaluated both direct and indirect energy across the entire urban water cycle from abstraction to discharge and reclamation. By considering the energy embodied in pipelines and energy avoided from circular water use, this study compared the energy burdens and benefits of long-range piped water supply options (local supply and inter-basin import) and decentralized circular supply options (rainwater harvesting, greywater reuse, wastewater recycling, water loss reduction, water demand management). The results showed that conventional piped water supply options were still more energy-efficient than decentralized rainwater harvesting, greywater reuse, and some wastewater recycling options. In the case of Paju, advanced treatments required to provide high-quality industrial water made circular water options particularly less energy-efficient. The trade-offs between water security and energy use would be further strengthened in 2040, when the energy needs of the city's water supply increase by 27%. Expansion of the wastewater recycling would add 11% of the energy needs, whereas adoption of water-saving appliances in residential buildings decrease energy needs by 6%. For energy-efficient water management, Paju needs to consider adopting water demand management options, optimizing reclamation technologies and size, and harvesting renewable energy.

Demand management approaches in services sector and influence on company performance

PurposeThe purpose of this paper is to empirically examine the impact of supply chain risks (SCRs) and demand management strategies (DMSs) on the company performance in order to study the use of DMSs in delivering improved results even in the presence of SCRs. The SCRs considered under the study are as follows: demand variability, constrained capacity and quality of services delivery, and competitive performance, customer satisfaction and financial performance are the measures considered for company performance.Design/methodology/approachThis study is based on a survey of 439 businesses in India representing 10 groups of services industries (information technology/IT enabled services, business process outsourcing, IT infrastructure, logistics/transportation, healthcare, hospitality, personal services, consulting, education and training, consumer products and retail), using structural equation modeling (SEM) methods.FindingsThe findings reveal that presence of demand variability risk has significant influence upon the use of demand planning and forecasting, controlling customer arrival during peaks and shifting demand to future. Mismatch of capacity against demand (unused capacity) leads to the use of techniques to influence business during lean periods, thereby resulting in enhanced supply chain (SC) and financial performance. Controlling customer arrival during peaks to shift the demand to lean periods leads to enhanced financial performance. Presence of delivery quality risk does not significantly influence the use of DMS. Also, short-term use of customer and business handling techniques does not exert significant influence on company performance.Research limitations/implicationsThe study has limitations as follows: (1) respondents are primarily from India while representing global organizations, (2) process/service redesign to relieve capacity as a DMS is not considered and (3) discussion on capacity management strategies (CMSs) is also excluded.Practical implicationsSC managers can be resourceful in shifting the peak demand to future with the application of techniques to control customer arrival during peaks. The managers can also help enhance business by influencing business through offers, incentives and promotions during lean periods to use available capacity and improve company performance.Originality/valueThis study is one of the first empirical works to explore how presence of SCRs influences the use of DMS and impacts the three types of company performance. The study expands current research on demand management options (DMOs) by linking three dimensions of company performance based on the data collected from ten different groups of service industry.

Climate change and reservoir sedimentation implications for irrigated agriculture in the Indus Basin Irrigation System in Pakistan

Pakistan relies greatly on the water of the Upper Indus basin (UIB) for its vast agriculture in the Indus Basin Irrigation System (IBIS). There are already concerns about the extent of unsustainable water use in the IBIS, particularly of groundwater, and these concerns are likely to increase in the future due to population increase and associated increased demand for food. In addition, climate change, continuing reservoir sedimentation in the major dams, and other impacts on water supply and demand are likely to have an impact on the practical implementation of the landmark inter-provincial Water Apportionment Accord (the Accord), which governs surface water allocation in the IBIS. There is, therefore, a need to assess the sustainability of irrigation in light of the potential variations of water availability in the basin under a series of plausible climate change and reservoir sedimentation scenarios.In this paper, we examine the impact of continuing reservoir sedimentation and climate change by 2050 on the water balance of canal commands in the IBIS. Firstly, we used a river system model, the first to include water management rules as in the Accord, to propagate climate induced changes on flows in the UIB and their impact on IBIS flow regulation and canal deliveries (Icw), with and without reservoir sedimentation. Secondly, we used a selection of General Circulation Models (GCMs) that showed skill at simulating the local climate of the IBIS to assess the projected changes to rainfall (Pn) and evapotranspiration (ETa). The analysis revealed that water balances in IBIS canal command areas are more significantly affected by changed inflows from the UIB than by localised climate induced changes (i.e. Pn and ETa). Continuing reservoir sedimentation in the dams to 2050 will diminish the capacity of the system to store flows during the wet summer Kharif season for its later release in the dry winter Rabi season. This will decrease the supply of Icw in the Rabi season to the downstream IBIS areas in Sindh and Balochistan provinces, and potentially increase supplies in the Kharif season. The impact of reservoir sedimentation on the Rabi water supply (33 mm (13%) decrease in median Icw, equivalent to 1.89 km3), is greater than the impact of projected localised climate change within the IBIS (2 mm (12%) decrease in median Pn, equivalent to 0.13 km3). Sedimentation combined with climate change decreases the median Icw by 51 mm (20%, equivalent to 2.91 km3) in Rabi in the low flow scenario and increases it by 48 mm (8%, equivalent to 2.72 km3) in Kharif in the high flow scenario. In the upstream Punjab province, however, reservoir sedimentation will have limited impact by 2050 due to lower ETa in Rabi and the availability of groundwater. Continued reservoir sedimentation beyond 2050 will also affect Punjab, again diminishing the supply of Icw in Rabi and increasing it in Kharif. Concurrently, declining Icw could lead to a substantial reduction in crop areas in the Rabi season. To avoid this undesirable scenario, Pakistan needs to explore both demand and supply management options to achieve food and economic security, as well as controlling sedimentation rates in reservoirs.

Simulating the impact of water demand management options on water consumption and wastewater generation profiles

ABSTRACT This paper describes the development and application of a simulation tool to assess the impact of water-efficient appliances and greywater recycling strategies on the domestic water consumption and wastewater generation profiles. Two time-series datasets of domestic water consumption in UK households – each consisting of more than 20,000 observations – were used to deduce water use appliance usage patterns as a function of water consumption per use for each water-use appliance and household characteristic (e.g. occupancy). The deduced trends were then used to develop a simulation tool that can generate water consumption and wastewater generation profiles reflecting user input for water use appliances and household characteristics. The inbuilt flexibility in the tool allows investigation of each water use appliance both individually and collectively, and facilitates informed decision-making for devising targeted retrofitting programmes. This research has application for water service provision and policy making globally, with potential impact on both water supply and wastewater management.

A sustainable urban water management model under uncertainty: a case study

PurposeTackling the challenges of water scarcity requires comprehensive management according to financial, environmental and social issues. This paper aims to develop a planning approach for systematic decision-making and pay attention to uncertainties in water demand management and supply investment.Design/methodology/approachThis study presents a multiobjective optimization model to manage water resources based on the balance of supply and demand. The objectives of the model include economic, social and environmental (sustainable development) factors. The model achieves an optimal urban water portfolio by using a scenario tree.FindingsThe mathematical goal programming (GP) in a multiobjective optimization model is applied and solved by the branch and bound method. The results indicate the selected supply augmentation and demand management options in each stage for 20 years according to the dry, normal and wetness year scenarios.Practical implicationsThis model is based on a real-world case and has been implemented in the city of Karaj. It can be applied for water management of other cities concerning sustainable development as well.Originality/valueThis paper innovates by considering the sustainable development criteria that are defined using three objective functions, including economic, social and environmental factors. The balance of supply and demand concerning uncertainty has not been investigated in any urban water portfolios. The standardized precipitation evapotranspiration index (SPEI) is incorporated to generate different scenarios. To the best of the authors’ knowledge, this approach is used for the first time.

Planning for urban water supply–demand portfolio using a hybrid robust stochastic optimization approach

Abstract Water management and preventing water shortage require accurate planning with attention to the importance of urban water. The problems ahead include the increase in demand and reduction in water supply resources due to factors that cause uncertainties and the high cost of water supply infrastructures. Most studies in urban water management consider only a single criterion. However, in this research, two objective functions, namely cost minimization and per capita water consumption maximization, were used simultaneously. A portfolio approach based on the balance of water supply and demand was developed taking uncertainty into account. Then, the problem was solved using a hybrid robust–stochastic optimization approach. The results showed the selected supply augmentation and demand management options in each stage under dry, normal, and wet year scenarios.

Sustainable household water-saving and demand management options for Kabul City

Increasing water demand has led to water scarcity in many urban areas in the arid and semi-arid regions. Indeed, population growth and the expansion of urban and industrialized areas have put great pressure on water resources. Currently, Kabul city is facing groundwater shortage, which is the main source of potable water. Due to rapid urbanization and population growth, and climate impacts, the groundwater level is lowered (∼ 1m/year), which has led to many wells drying out in recent years since 1998. Therefore, this study focuses on alternative options to sustain water resources and achieve water sustainability through implementing water-saving practices, including tapping new water resources (rainwater harvesting), and some of the options (faucet aerators, low-flow showerheads, and dual flush toilets), others as gray-water reuse. To analyze the potential of rainwater in Kabul city, long-term precipitation data from 1960-1980 and 2006-2013 from several stations around the city are used. The rooftops of the dwellings assumed to account for 30% of the total land area, according to the State of Afghanistan City 2015 report. Moreover, existing household water efficiency is compared to the most efficient available technologies. The result indicated 346 mm annual average precipitation, and 38.0 million m3/Year the potential precipitation volume that could be harvest from dwellings rooftops in Kabul city. Moreover, the rainwater harvesting could produce an average of 29 L/capita/day (LCD) of water for domestic usage, with a maximum of 75 LCD in February, a minimum of 5 LCD in September, and an annual 9593 L/capita/year (LCY). If we manage the maximum months, then it could produce the full domestic usage (38.1 LCD) until July. Furthermore, in terms of demand management, we have performed a case study on Macrorayon’s (1st, 2nd, 3rd, 4th) apartments that if low flow fixtures were utilized, how much water could be saved? The Macrorayon Department estimates the service population of its system at 100,000 people, the volume of consumption calculated to be 12,500 m3/day (125 LCD). Results show that after application of low flow fixtures, per capita consumption can be reduced to 57 LCD, 2.08 MCM/Year would be saved; and an additional population of 119,298 people would be covered by water supply. The result of this study is essential for policymakers to adopt current and future water challenges in Kabul city.

Impact Analysis of Demand Management on Runway Configuration in Metroplex Airports

Congestion in airports and metroplexes is increasingly becoming a key bottleneck in the global air transport system. It is largely due to inefficient utilization of runway resources and its consequences of imbalance between demand and capacity. Existing studies mainly focus on runway configuration in a single airport system, and little consideration is given to the impact of demand management on runway configuration in metroplexes. Therefore, this paper proposes a methodology and assessment framework for runway configuration with a focus on the exploitation of multiple active runways in metroplex airports. The primary innovation is an integrated runway configuration management formulation with air traffic demand management options. The first is static and dynamic runway configuration management models featuring three optimization objectives, four cases of demand-capacity imbalance, three air traffic demand management options and three assessment scenarios, for eleven priority settings. The second is an efficient multi-objective evolutionary algorithm with a mechanism of objective-guided individual selection, which can obtain close-to optimal solutions with a very low computational cost within 6 seconds. Computational experiments for the real-world case of the Shanghai metroplex airports show that, the inducing strategy of minimizing the total number of adjusted flights is the best mechanism for making satisfactory tradeoffs among multiple objectives in dynamic runway configuration. The proposed model reduces the total number of adjusted flights by an average of 36% compared with the baseline static runway configuration management. Furthermore, unlike the conventional approach of giving priority to arriving aircraft, a higher priority for departures is more effective in enhancing the performance of runway systems and reducing the number of adjusted flights. The proposed framework can be applied at pre-tactical (e.g., one-day planning) as well as tactical (e.g., several-hours rolling horizon) levels.

Decision-dependent uncertainty in adaptive real-options water resource planning

Staged water infrastructure capacity expansion optimization models help create flexible plans under uncertainty. In these models exogenous uncertainty can be incorporated into the optimization using an a priori hydrological and demand scenario ensemble. However some water supply intervention uncertainties cannot be considered in this way, such as demand management or technological options. In these cases the uncertainty is endogenous or ‘decision-dependent’, i.e., the optimized timing and selection of interventions determines when and which uncertainties must be considered. We formulate a multistage real-options water supply capacity expansion optimization model incorporating such uncertainty and describe its effect on cost and option selection.

Assessing social acceptability of management options for harmonising irrigation with environmental concerns: A pilot study from the Murrumbidgee Valley, Australia

The flows in regulated rivers are strongly dependent on water demand by downstream water users. In irrigated catchments the river flow regimes are deliberately distorted to cater for crop demand, with significant deleterious ecological impacts. A number of opportunities exist to manipulate irrigation demand and supply to provide more natural seasonality of flows and optimise the social, environmental and economic outcomes from water use in a catchment. Possible options to achieve this goal include improved cropping mix incentives, groundwater - surface water substitution, intra and inter-seasonal water trading and harmonisation of on- and off-farm storage, distribution, application and drainage infrastructure with environmental outcomes. Each of these options will impact in some way on irrigation and wider communities. In this paper 'community' involvement in setting irrigation research agendas and evaluating water management options in the Murrumbidgee Valley, Australia is explored. A brief assessment of social acceptability, combined with hydrological and economic models, was found to be an effective approach for scoping different irrigation demand management options to improve seasonality of flows. In this study the value of articulating assessment criteria when dealing with new and potentially disruptive options for the management of irrigation demand in a catchment context is demonstrated.

Ecosystem Service Impacts of Urban Water Supply and Demand Management

Utilities face the challenge of enhancing long-term water security while minimising undesirable economic, social and environmental impacts of supply and demand management options. This paper provides an example of how the ecosystem services concept can be used to enumerate and organise broad impacts of water supply options. A case study of Adelaide, South Australia, is used to examine costs and benefits associated with different sources of water and source-water mix scenarios. Ecosystem service impacts are estimated using estimates from the literature. Seven water supply and demand management options are considered for Adelaide: 1) the River Murray, 2) Mt. Lofty Ranges catchments, 3) wastewater reuse, 4) desalination, 5) stormwater harvesting, 6) groundwater and 7) water conservation. The largest costs are associated with sourcing water from conservation measures such as water restrictions on outdoor watering estimated at $1.87/kL. Salinity damage costs associated with residential uses are estimated at up to $1.54/kL. Salinity damage costs of wastewater reuse were estimated at $1.16/kL. The largest benefit is coastal amenity services associated with stormwater harvesting and treatment estimated at $1.03/kL. Results show that there is a trade-off between financial costs and ecosystem services impacts with source-water mix scenarios with the highest ecosystem services cost having the lowest financial O&M cost and vice versa. This highlights the importance of taking ecosystem services into account when evaluating water supply options.

Current and future groundwater withdrawals: Effects, management and energy policy options for a semi-arid Indian watershed

Effects of future expansion/intensification of irrigated agriculture on groundwater and surface water levels and availability in a semi-arid watershed were evaluated using an integrated hydrologic model (MIKE SHE/MIKE 11) in conjunction with biophysical measurements. Improved water use efficiency, water storage, and energy policy options were evaluated for their ability to sustain the future (2035) increased groundwater withdrawals. Three future withdrawal scenarios (low = 20, medium = 30, high = 50 wells/100 km2/year) based on the historical rate of growth of irrigation wells were formulated. While well drying from falling groundwater levels was limited to drought and consecutive below average rainfall years, under the current (2015) withdrawals, significant increases in frequency and duration (17–97 days/year) of well drying along with 13–26% (19–37 mm) reductions in surface flows were predicted under the future withdrawals. Higher (27–108%) energy demands of existing irrigation pumps due to declining groundwater levels and reduced hydroelectric generation due to decreased surface flows would create a vicious water-food-energy nexus in the future. Crop failure, one of the main causes of farmers’ emotional distress and death in the region, is predicted to exacerbate under the future withdrawal scenarios. Shift to negative net recharge (−63 mm) and early and prolonged drying of wells under the high scenario will reduce the groundwater availability and negatively affect crop production in more than 60% and 90% of cropped areas in the Rabi (November–February) and summer (March–May) seasons, respectively during a drought year. Individual and combined demand (drip irrigation and reduced farm electricity subsidy) and supply (water storage) management options improved groundwater levels and reduced well drying by 55–97 days/year compared to business-as-usual management under the high scenario. The combined management (50% drip conversion, 50% reduction in subsidy, and enhanced water storage) mitigated well drying even during drought and consecutive below average rainfall years under the high scenario. A conservative economic evaluation for management options under the high scenario showed increases in crop production and per farmer annual profits by $987–$1397 during a drought year (average household income = $1520/year). A scale-up of results showed that diverting 50% state power subsidy ($6 billion for 3–6 years) can almost entirely fund the conversion to drip irrigation ($4.2 billion) and water storage structures ($2.9 billion) and help meet the water supply demand of a 50% increase in irrigated area under the high scenario. Converting flood to drip irrigation in 50% of irrigated area under the high scenario can reduce the electric energy consumption (7 × 106Mwh/year) and carbon footprint (6000 Mt/year) of groundwater irrigation by 24% in the state. Management options considered can potentially create a sustainable water-food-energy nexus in the larger semi-arid hard rock region. Reducing the power subsidy will require a strong political will since it has been used as a tool to win the elections in India. Considering future agricultural intensification, timely interventions are needed to ensure the livelihood and well-being of millions of small- and medium-scale farmers that rely on low storage, hard rock aquifers in the semi-arid regions of the world.

Assessment of Sustainability of Urban Water Supply and Demand Management Options: A Comprehensive Approach

A comprehensive evaluation framework that can assess a wide range of water supply and demand management policy options in terms of economic, social, environmental, risk-based, and functional performance is crucial to ascertain their level of sustainability. However, such a detailed, generic, and holistic policy evaluation framework is not found in the literature. This paper reviews studies to evaluate water supply and/or demand management options conducted during 2000–2016. Primarily, the paper reviews the evaluation criteria used by different studies for decision making given their significant difference and the importance of a comprehensive set of criteria to complete a rigorous evaluation. In addition, a comprehensive set of water supply and demand management options are not considered together for a comparative assessment to prioritise best options for a certain area and time. Further, performance of these options needs to be evaluated for a range of uncertainties arising from changes of spatial and temporal variables of the system. While this paper highlights the important aspects that need to be included in a comprehensive policy evaluation framework, available studies collectively present a rich set of information to support it.

Demand management to mitigate impacts of plug-in electric vehicle fast charge in buildings with renewables

Plug-in electric vehicle penetration is increasing due to technical advancements and environmental concerns. Along with residential plug-in electric vehicle charging, the public charging infrastructure is much needed to reduce plug-in electric vehicles' range anxiety and foster their adoption. Renewable energy and demand management programs are considered viable options that can reduce the impacts of widespread plug-in electric vehicle penetration on the electric grid. This research studies the impacts of plug-in electric vehicle direct current fast charging on a simulated standalone retail building's peak demand and energy consumption, and presents the ability of renewable energy and demand management options to reduce their impacts. Additionally, insights into a public charge station usage are presented by monitoring different types of plug-in electric vehicle charge behaviors at a retail site. Research findings indicate that demand management of building end-use loads along with the use of solar photovoltaic can contribute to absorbing plug-in electric vehicle penetration at the building level ranging from the average of 7% for the demand management option alone to an average of 38% for the combination of demand management and solar photovoltaic, and contributing to shifting building peak demand to late evening hours.

Assessment of Retrofitting Measures for a Large Historic Research Facility Using a Building Energy Simulation Model

A calibrated building simulation model was developed to assess the energy performance of a large historic research building. The complexity of space functions and operational conditions with limited availability of energy meters makes it hard to understand the end-used energy consumption in detail and to identify appropriate retrofitting options for reducing energy consumption and greenhouse gas (GHG) emissions. An energy simulation model was developed to study the energy usage patterns not only at a building level, but also of the internal thermal zones, and system operations. The model was validated using site measurements of energy usage and a detailed audit of the internal load conditions, system operation, and space programs to minimize the discrepancy between the documented status and actual operational conditions. Based on the results of the calibrated model and end-used energy consumption, the study proposed potential energy conservation measures (ECMs) for the building envelope, HVAC system operational methods, and system replacement. It also evaluated each ECM from the perspective of both energy and utility cost saving potentials to help retrofitting plan decision making. The study shows that the energy consumption of the building was highly dominated by the thermal requirements of laboratory spaces. Among other ECMs the demand management option of overriding the setpoint temperature is the most cost effective measure.

Adaptation of water resource systems to an uncertain future

Abstract. Globally, water resources management faces significant challenges from changing climate and growing populations. At local scales, the information provided by climate models is insufficient to support the water sector in making future adaptation decisions. Furthermore, projections of change in local water resources are wrought with uncertainties surrounding natural variability, future greenhouse gas emissions, model structure, population growth, and water consumption habits. To analyse the magnitude of these uncertainties, and their implications for local-scale water resource planning, we present a top-down approach for testing climate change adaptation options using probabilistic climate scenarios and demand projections. An integrated modelling framework is developed which implements a new, gridded spatial weather generator, coupled with a rainfall-runoff model and water resource management simulation model. We use this to provide projections of the number of days and associated uncertainty that will require implementation of demand saving measures such as hose pipe bans and drought orders. Results, which are demonstrated for the Thames Basin, UK, indicate existing water supplies are sensitive to a changing climate and an increasing population, and that the frequency of severe demand saving measures are projected to increase. Considering both climate projections and population growth, the median number of drought order occurrences may increase 5-fold by the 2050s. The effectiveness of a range of demand management and supply options have been tested and shown to provide significant benefits in terms of reducing the number of demand saving days. A decrease in per capita demand of 3.75 % reduces the median frequency of drought order measures by 50 % by the 2020s. We found that increased supply arising from various adaptation options may compensate for increasingly variable flows; however, without reductions in overall demand for water resources such options will be insufficient on their own to adapt to uncertainties in the projected changes in climate and population. For example, a 30 % reduction in overall demand by 2050 has a greater impact on reducing the frequency of drought orders than any of the individual or combinations of supply options; hence, a portfolio of measures is required.

Future Water Supply and Demand Management Options in the Athabasca Oil Sands

The Athabasca River Basin, home to Canada's growing oil sands mining industry, faces challenging trade-offs between energy production and water security. Water demand from the oil sands mining industry is projected to increase as climate change is projected to alter the seasonal freshwater supply. In this study, a range of water management options are developed to investigate the potential trade-offs between the scale of bitumen production and industry growth, water storage requirements, and environmental protection for the aquatic ecosystems, under projections of mid-century climate change. It is projected that water storage will be required to supplement river withdrawals to maintain continuous bitumen production under the impacts of future climate warming. If high growth in future bitumen production and water demand is the priority, then building sufficient water storage capacity to meet industry demand will be comparable to a week of lost revenue because of interrupted production. If environmental protection is prioritized instead, it will require over nine times the water storage costs to maintain water demand under a high industry growth trajectory. Future water use decisions will need to first, determine the scale of industry and environmental protection, and second, balance the costs of water storage against lost revenue because of water shortages that limit bitumen production. This physically based assessment of future water trade-offs can inform water policy, water management decisions, and climate change adaptation plans, with applicability to other regions facing trade-offs between industrial development and ecosystem water needs. Copyright © 2016 John Wiley & Sons, Ltd.

Many-objective optimization and visual analytics reveal key trade-offs for London’s water supply

In this study, we link a water resource management simulator to multi-objective search to reveal the key trade-offs inherent in planning a real-world water resource system. We consider new supplies and demand management (conservation) options while seeking to elucidate the trade-offs between the best portfolios of schemes to satisfy projected water demands. Alternative system designs are evaluated using performance measures that minimize capital and operating costs and energy use while maximizing resilience, engineering and environmental metrics, subject to supply reliability constraints. Our analysis shows many-objective evolutionary optimization coupled with state-of-the art visual analytics can help planners discover more diverse water supply system designs and better understand their inherent trade-offs. The approach is used to explore future water supply options for the Thames water resource system (including London’s water supply). New supply options include a new reservoir, water transfers, artificial recharge, wastewater reuse and brackish groundwater desalination. Demand management options include leakage reduction, compulsory metering and seasonal tariffs. The Thames system’s Pareto approximate portfolios cluster into distinct groups of water supply options; for example implementing a pipe refurbishment program leads to higher capital costs but greater reliability. This study highlights that traditional least-cost reliability constrained design of water supply systems masks asset combinations whose benefits only become apparent when more planning objectives are considered.

Employing Water Demand Management Option for the Improvement of Water Supply and Sanitation in Nigeria

The aim of this paper is to assess the importance of Water Demand Management (WDM) strategy to the improvement of water supply and sanitation in Nigeria. Persistent water supply shortages and poor sanitation have since remained important features of the Nigerian urban and rural communities. Most often governmental solution to these problems has been to develop and exploit the available water resources and the level of sanitation for the people. This predominant approach which is also known as augmentation method is supply driven with the primary purpose being how best to meet the perceived water and sanitation demand. One of the major disadvantages of this approach is the huge financial involvement associated with it. Conversely, quite recently water resource managers have begun to direct attention on how consumers can be motivated to regulate the amount and manner in which they use and dispose water to alleviate pressure on freshwater supplies. This new approach is known as water demand management. It is demand driven in that consumers determine their own water need. Employment of WDM by consumers especially in water scarce areas as was discussed in the paper will decrease the amount of water use, thereby limiting unnecessary financial expenditure in exploiting new sources to meet the ever increasing demand.

Development, water and energy in the context of climate change in North Africa

This article adopts a holistic approach to explore and quantify interactions between water and energy in the context of climate change in North Africa. We bring together results from different research areas to describe the physical interactions and to shortly discuss governance issues in the sectors of water and energy. We highlight the fact that water demand management options combined with a sustainable energy model is a priority action to answer the challenge of climate change adaptation in North African countries. We use the IPAT formula approach to compute scenarios for quantifying the magnitudes of advantages to expect from water demand side management actions coupled with energy efficiency options. According to our results, water demand management is a very appropriate adaptation option with significant benefits in terms of water saving, energy use and energy bill. Overall, in 2050, the water saved thanks to demand management actions could be around 68 billion of cubic meters, which is the magnitude of the total water demand of Egypt in 2005. Depending on the scenario and assumptions, the expected cumulated benefit in terms of energy bill over the period 2005–2025 could range between 30 and 48 billion US Dollar, which is comparable to the GDP of Tunisia in 2011 (46 billion US Dollar). Nevertheless, up to 2050, regardless the scenario, additional options will be needed to cover the water deficit of the region. This leads us to consider virtual water as an additional option to reduce the local water demand. Finally, we discuss the political implications and the reforms to be implemented for integrating water and energy demand side policies in North Africa.