Urban Residential Water Demand Research Articles

Urban Residential Water Demand and Household Size: A Robust Meta‐Regression Analysis*

We present the results of a meta‐analysis of household‐size water demand elasticity. The analysis is based on 75 primary studies. As there is evidence of publication bias, publication bias–corrected estimates are reported. For indoor water use, we find that in countries with gross domestic product (GDP) per capita below $10,000, the household‐size elasticity is approximately 0.4–0.5, and in countries with GDP per capita above $10,000, it is approximately 0.5–0.6. For outdoor water use, we find that there is no increase in water use as household size increases, at low incomes (GDP less than $5000 per capita), but the effect becomes positive at higher incomes. In countries with a GDP per capita between $5000 and $15,000, the household‐size outdoor water use elasticity is approximately 0.1, and in countries with a GDP per capita above $15,000, it is approximately 0.2. The positive household‐size elasticity implies that the cost of meeting basic water needs, per person, increases with household size in countries that use increasing block pricing for water. The use of a single volumetric price, equal to marginal cost, combined with a fixed charge, would lessen this effect and also improve system efficiency.

User-based fuzzy end-use modeling of indoor urban residential water demand

Stochastic models for estimating residential water demand use high-resolution field data consuming large costs and significant time. An attempt for the accurate estimation of water demand may result in its complex analytical model due to numerous factors affecting the water use event. Moreover, as the water supply system is always subjected to variations in demand, the accuracy of water demand estimation in its design can be side-lined. The water demand in residential buildings is mainly governed by the users’ characteristics and their daily schedule. In this view, the use of Fuzzy Logic can be advantageous to model the uncertainty in water demands. The presented study attempts to provide a methodology to estimate urban indoor residential water demand with the help of user-based end-use models in the absence of field data and generate various possible water demand patterns of fixtures. Usergroups were created for assuming spatial variations in water demand. Fuzzy Logic was used to develop the end-use models using data on urban users’ characteristics, their diurnal activities, and water use habits to estimate the demand characteristics of fixtures. The model may also facilitate the computation of pipe sizing in building water supply systems.

Determinants of urban residential water demand in Libya

This paper analyses the effect of several economic, environmental and social determinants for the per capita demand for water in Libya. In this study, the econometric model based on E-views method, instrumental and ARDL model are applied. The cointegration analysis has shown a significant positive effect of temperature on water demand over the short and long term. Also, there is a positive relationship between rainfall and water demand in the long term and its less impact in the short term. There is a significant positive relationship between urban population and water demand. On the other hand, there is a significant negative effect of income on water demand. Therefore, water demand is inflexible to changes in income. The study demonstrated that there is a negative effect on water price in relation to water demand. The estimated long-term variable of water value is 220.98.

Determinants of urban residential water demand in Libya

This paper analyses the effect of several economic, environmental and social determinants for the per capita demand for water in Libya. In this study, the econometric model based on E-views method, instrumental and ARDL model are applied. The cointegration analysis has shown a significant positive effect of temperature on water demand over the short and long term. Also, there is a positive relationship between rainfall and water demand in the long term and its less impact in the short term. There is a significant positive relationship between urban population and water demand. On the other hand, there is a significant negative effect of income on water demand. Therefore, water demand is inflexible to changes in income. The study demonstrated that there is a negative effect on water price in relation to water demand. The estimated long-term variable of water value is 220.98.

Determinants of Urban Residential Water Demand in Libya

This article analyzes the effect of several economic, environmental and social determinants for the per capita demand for water in Libya. Besides prices, income and population size, the article reflects the impact of urban population size, the temperature, summer temperature, and precipitation. The article also explores why the current per capita residential water demand in the urban areas is about more than in the other areas in Libya. In this study, the econometric model based on E-views method, instrumental-variable procedures, the ARDL model and the demand equation are applied. The co-integration analysis has shown a significant positive effect of temperature on water demand over the short and long term with partial flexibility of long-term temperature (5.44). Also, there is a positive relationship between rainfall and water demand in the long term and its less impact in the short term. There is a significant positive relationship between urban population and water demand. The greater urban population is greater the water demand and vice versa, partial flexibility of the urban population in the long term is at 0.23. On the other hand, there is a significant negative effect of income on water demand. Therefore, water demand is inflexible to changes in income. The study demonstrated that there is a negative effect on water price in relation to water demand. The estimated long-term variable of water value is 220.98, indicates that if the water price increases by 100%, the demand for water will go down by 221%.

A study on the spatial and temporal variability of the urban residential water consumption and its influencing factors in the major cities of China

In recent years, urban residential water demand has continually grown with the rapid urbanization in China, which has been the main contributor to the increase of total urban water consumption. The fast growth of urban water consumption poses a great threat to urban water security and sustainable water resources management. To explore the dominant factors influencing the urban residential water consumption and further to propose the effective measures to control the fast growth of water consumption, this study selected the daily water consumption per capita (DWCC) as an indicator to quantitatively characterize the residential water consumption level and analyzed the spatial and temporal characteristics of DWCC in the period of 2005–2014 based on the data collected from 38 major cities in China. The results showed that the average values of DWCC in the 38 major cities were 141.9 L/d, 159.4 L/d and 129.3 L/d in 2005, 2010 and 2014 respectively. The urban residential water consumption showed a significant decreasing trend in the period of 2005–2014 due to the strategy of water-saving society construction in China. Meanwhile, the DWCC was showing a great spatial variability among different cities, which was much greater in southern cities than that in northern cities. The reason behind this is that the main influencing factors differ greatly among different cities. Based on the path analysis, we also identified the dominant factors influencing the DWCC from the 9 main possible factors. The amount of available water resources, the domestic water price and the usage rate of water-saving appliances are recognized as the dominant influencing factors. At last, the differential countermeasures are proposed to improve the urban water-saving management level and guarantee the urban water security in China.

Have Chinese water pricing reforms reduced urban residential water demand?

AbstractChina continues to deal with severe levels of water scarcity and water pollution. To help address this situation, the Chinese central government initiated urban water pricing reforms in 2002 that emphasized the adoption of increasing block rate (IBR) price structures in place of existing uniform rate structures. By combining urban water use records with microlevel data from the Chinese Urban Household Survey, this research investigates the effectiveness of this national policy reform. Specifically, we compare household water consumption in 28 cities that adopted IBR pricing structures during 2002–2009, with that of 110 cities that had not yet done so. Based on difference‐in‐differences models, our results show that the policy reform reduced annual residential water demand by 3–4% in the short run and 5% in the longer run. These relatively modest reductions are consistent with the generous nature of the IBR pricing structures that Chinese cities have typically chosen to implement. Our results imply that more efforts are needed to address China's persistent urban water scarcity challenges.

Prediction of urban residential end-use water demands by integrating known and unknown water demand drivers at multiple scales II: Model application and validation

Detailed prediction of end-use water demand at multiple spatial and temporal scales is essential for planning urban water supply using multiple water sources based on fit-for-purpose criteria. This paper presents the application of a stochastic model to predict urban residential end-use water demands at multiple spatial and temporal scales. The model includes an improved representation of spatial and temporal variability of urban residential water use by considering the effect of a significant number of water demand drivers such as household size, dwelling type, appliance efficiency, availability of water end-uses/appliances at dwellings, presence of children, presence of people at home, diurnal behavioral patterns and temperature. A stochastic approach is used to describe the variability of residential water demand that is not captured by these known explanatory variables. The model is validated against quarterly meter readings and hourly water use data. The validation of household water demand at a quarterly scale with billing data shows Correlation coefficients (R2) ranging between 90% and 96% and Nash-Sutcliffe coefficients ranging between 0.70 and 0.92 for the four seasons analyzed which, verifies the predictive capacity of the model. The model validation also demonstrates the statistical stability of the selected probability distributions used in modeling the unexplained behavior of urban residential water consumers. The hourly scale validation also demonstrates a satisfactory predictive capacity in predicting household water demand. This also evidences the effectiveness of the modeling approach to predict urban residential water demand at multiple temporal scales.

Prediction of urban residential end-use water demands by integrating known and unknown water demand drivers at multiple scales I: Model development

Detailed prediction of water demand by their end-uses at multiple scales is essential to support planning of Integrated Urban Water Management, an increasingly applied approach to deal with the problem of water scarcity. This paper presents an urban residential water demand modeling framework that can predict end-use water demand at multiple scales, especially at small scales with a robust explanatory capacity. This is achieved by integrating the complex water demand dynamics of urban residential water use and their underlying variables into a single model. The model described in this study can predict shower, toilet, tap, dishwasher, clothes washer, irrigation, evaporative cooler, bath, and other uses which account for the entire household water use. The model aims to predict water demand at multiple spatial (household/cluster/suburb) and temporal scales (hourly, daily, weekly and seasonal) by considering behavioral differences triggered by factors such as seasonality and presence of people at home. The model incorporates an improved representation of spatial variability by considering behavioral differences between customer groups, and improves the capability to deal with areas with different demographic and housing characteristics. This research confirms the capacity of stochastic modeling methods to represent unexplained behavior of water consumers.

Urban Residential Water Demand Prediction Based on Artificial Neural Networks and Time Series Models

Water demand prediction is essential in any short or long-term management plans. For short-term prediction of water demand, climatic factors play an important role since they have direct influence on water consumption. In this paper, prediction of future daily water demand for Al-Khobar city in the Kingdom of Saudi Arabia is investigated. For this purpose, the combined technique of Artificial Neural Networks (ANNs) and time series models was constructed based on the available daily water consumption and climatic data. The paper covers the following: forecast daily water demand for Al-Khobar city, compare the performance of the ANNs [General Regression Neural Network (GRNN) model] technique to time series models in predicting water consumption, and study the ability of the combined technique (GRNN and time series) to forecast water consumption compared to the time series technique alone. Results indicate that combining time series models with ANNs model will give better prediction compared to the use of ANNs or time series models alone.

How Do Residents Respond to Price under Increasing Block Tariffs? Evidence from Experiments in Urban Residential Water Demand in Beijing

Economic theory generally assumes that consumers respond to marginal price, which is the price of the last unit of goods consumed, when making economic decisions. However, this assumption may not hold for goods with multi-block rate schedules. This paper explores the effects of water price information on residents’ behaviors under increasing block tariffs. The empirical evidence from the study suggests the middle-income groups respond to average price, which is based on the price level given by total fees divided by total consumption. This evidence supports the hypothesis that the incremental block tariffs are actually treated the same as uniform pricing for the middle-income group, while the highest income group is not sensitive to price changes. On the contrary, residents of the two lowest income groups respond to marginal price and probably go further to compare prices of different blocks and set consumption at kink points of price schedules to achieve maximal welfare. This study also finds that a higher second block price promotes consumption at kink points, and increased payments in first block consumption lead to less incentive to induce discrete choice behavior.

Spatial Determinants of Urban Residential Water Demand in Fortaleza, Brazil

This paper aims at estimating the residential water demand function for the city of Fortaleza, Brazil, considering the potential impact of including spatial effects in the model. The empirical evidence is a unique micro-data set obtained through a household water consumption survey carried out in 2007. We estimated three econometric models, which have as explanatory variables the average/marginal price, the difference, income, number of male and female residents and the number of bathrooms, under different spatial specifications: the Spatial Error Model (SEM), the Spatial Autoregressive model (SAR), and finally, the Spatial Autoregressive Moving Average model (SARMA). Results suggest that the SARMA model is the “best” as shown by a series of tests. Such results contradict conclusions drawn by Chang et al. (Urban Geogr 31(7):953–972, 2010), House-Peters et al. (JAWRA J Am Water Resour Assoc 46(3), 2010), and Ramachandran and Johnston (2011). This means, among other things, that not controlling spatial effects is a key specification error, underestimating the effect of almost all variables in the model. Sometimes, these differences can be as high as 24.66 % and 13.32 % for price elasticity in the Average Price and the McFadden models, respectively.

Evaluation of plumbed rainwater tanks in households for sustainable water resource management: a real-time monitoring study

In recent years, there has been a significant emphasis placed on achieving reductions in urban residential water demand through the application of alternative water resources on various housing development scales based on a “fit-for-purpose” concept. One such resource is rainwater that could be used in various non-potable applications at household level in urban areas. Savings in mains water achieved through the inclusion of rainwater as a source for residential use are plausible; however, analyses on quantifying the actual reduction in mains water demand are still at an early stage to incorporate into strategic planning for urban water supply. This paper highlights the real-time monitoring outcomes of 20 detached households with plumbed rainwater tanks in an attempt to assess their volumetric reliabilities, diurnal water demand patterns and water energy nexus. The rainwater usage (or mains water saving) was validated and assessed using 12 months monitoring data and an average yearly rainwater usage of 40 kl/household was found. The volumetric reliability, which is the ratio of the rainwater usage to the total household water demand, was found to be on average 31%. The instantaneous peak water demand was estimated to range between 16 and 93 l/min within the monitored homes, which has a strong implication for the design of household water supply system. Furthermore, the specific energy usage for rainwater supply in the 20 homes was estimated to be 1.52 kWh/kl. This study constitutes important research which provides critical input into strategic urban water planning for sustainable water resource management. The study is focussed on the South East Queensland region of Australia but the methodology developed for the monitoring and assessment of water savings in households with plumbed rainwater tanks will be useful for adoption worldwide by water professionals engaged in alternative water resources planning for urban developments.

Impacts of water demand side policies on Mongolian residential users

The water industry in Ulaanbaatar, Mongolia, experiences water scarcity and managerial and economic problems due to global warming and financial crises. This paper explores several possible solutions by analysing householders' stated attitudes towards and stated (predicted) responses to different demand side policies. Using data from a survey of approximately 660 households (HHs) in Ulaanbaatar, this research is a seminal study of Mongolian residential water demand and is the first time the contingent behaviour method (CBM) has been employed to estimate price elasticity of water demand in this country. The CBM is particularly useful in data-poor environments, where one cannot use actual data to generate estimates. In this study, researchers use stated responses to a series of hypothetical changes in price to generate estimates of the price elasticity of demand for water of different types of HHs, including residents of formal apartments and those living in informal Ger areas, are characterized by a low level of public services, including water and sanitation services of the city. Householders' attitudes towards different price and non-price policies are also examined. The findings are of interest to those wishing to postpone water scarcity by better managing urban residential water demand – particularly in transit and developing economies.

Household size and residential water demand: an empirical approach*

The effectiveness of pricing policies depends on the price elasticity of consumption. It is well documented that residential demand for water is influenced by heterogeneity associated with differences in the size of the household and socioeconomic characteristics. In this paper, we focus on household size. Our initial hypothesis is that users’ sensitivity to changes in price is different depending on the number of household members. To this end, we carry out an empirical estimation of urban water demand in Zaragoza (Spain) distinguishing between households with different sizes using data at the individual level. As far as we are aware, this approach to urban residential water demand is new in the literature. The analysis suggests that all households are sensitive to prices regardless of size. A more relevant finding is that small households are more sensitive to price changes.

Potential for Pricing Policies in Water Resource Management: Estimation of Urban Residential Water Demand in Zaragoza, Spain

This paper presents an empirical study to estimate the urban residential water demand in Zaragoza, Spain; this allows the testing of the short-run sensitivity of water demand to changes in a set of socioeconomic variables and especially in prices. A residential water demand model is estimated using a dynamic panel data technique. Furthermore, three water demand equations have been proposed and two alternative process specifications are applied. The empirical application suggests that the linear demand specification is the most adequate. Finally, the results indicate that domestic demands are inelastic with respect to price.

Price impact on urban residential water demand: A dynamic panel data approach

In this paper, we formulate and estimate a model of residential water demand with the aim of evaluating the potential of pricing policies as a mechanism for managing residential water. The proposed econometric model offers a new perspective on urban water demand analysis by combining microlevel data with a dynamic panel data estimation procedure. The empirical application suggests that residential users are more responsive to a lagged average price specification. Another result of the estimated model is that price is a moderately effective tool in reducing residential water demand within the present range of prices, with the estimated values for income elasticity and “elasticity of consumption with respect to family size” reinforcing this conclusion.

Estimating urban residential water demand: Effects of price structure, conservation, and education

Water demand equations are estimated using the most current American Water Works Association (1984) survey of 430 (of 600 largest) U.S. utilities. The data set was augmented by monthly rainfall and temperature data from the National Oceanic and Atmospheric Administration's climatological data. Demographic data were obtained from the U.S. Department of Commerce (1988). Besides the usual endogeneity problems involving block price structures this paper also examines the possible endogeneity of conservation and education programs. Three types of models were used: a marginal price model, an average price model, and Shin's (1985) price perception model. The results generally show that price elasticity is higher in the South and the West. Conservation does not appear to reduce water use, but public education appears to have reduced water usage in the West. The Shin (1985) tests in this study indicate that consumers react more to average than marginal prices in all regions.

Policy relevance in studies of urban residential water demand

Precise estimates of demand elasticities for a given area may not be necessary for policy purposes. Given the general nature of the demand for urban water, simple cross‐sectional comparisons of prices and quantities in similar areas may be most reliable for policy use. Short‐run elasticities give little information for policy purposes. Comparison of well‐defined price and quantity data from five cities with similar arid environments suggests a long‐run price elasticity for residential water of about −0.5 over a wide range of water prices. The potential for price adjustments to affect use is enormous.

Urban Residential Demand for Water in the United States

from recent severe drought and the substantial increase in urban population which has led to an increased demand for water by all sectors including residential, commercial, and industrial users. Concurrently, capital expenditures necessary to increase the capacity of any water system have increased dramatically due to a general price inflation which has offset advantages from economies of scale generated by technological change and improved operating efficiencies [Hanke 1975, p. 219]. The estimation of urban water demand has progressed from a requirements concept, to economic demand models in which the scope is limited to a homogeneous region and/or population, to generalized multivariate models covering the entire nation. This study presents a generalized model allowing for categorical effects due to regional and size-of-city differences on urban residential water demand.