Residential Water Demand Research Articles

Estimating Residential Water Demand in a Relocation Area with Inadequate Piped Water System

This paper assesses household water demand and estimates a demand equation particularly for low-income households in the Philippines. The study uses survey data on the value and volume of household water purchases from different water providers in a government resettlement area. The paper provides empirical evidence on the impact of average water price on household water consumption, as well as the effects of household income and size on household water consumption. The study finds that households buying water from jetmatic pump wells and water tankers pay more than five times that of those served by the piped water system. This much higher cost of water from non-Water District sources could have constrained their water consumption to just about half that of the Water District customers. The estimated water demand equation reveals that demand for water significantly decreases with the average price of water but is only weakly responsive to price changes, with a price elasticity of –0.38. It is also found that water demand is not significantly affected by household income implying that it is not the households’ low income but the unavailability of efficient water providers that constrains consumption to a bare minimum. These findings confirm the high vulnerability of low-income households to inadequate and inefficient water providers, necessitating more prudent programming of the resettlement areas’ water supply system.

A multilevel analysis of the drivers of household water consumption in a semi-arid region

Communities across the Western United States face the growing challenge of managing water resources in the face of rapid population growth and climate change. There are two contrasting approaches to understanding and managing residential water demand in this context. Many scientists and water managers see water use as a reflection of individual attitudes and decisions where people are assumed to have the agency to act independently of structural constraints. Conversely, other scientists and policymakers focus on the importance of the built environment and the broader social, economic, and policy contexts within which households make water decisions. Using multilevel models, we compared attitudinal, demographic, and structural drivers of indoor and outdoor residential water use for a sample of households in Northern Utah. We estimated multilevel mixed-effect Poisson models with robust standard errors using matched household survey data with metered residential water use records. Outdoor water use had a substantially greater amount of neighborhood-level variation than indoor water use. Structural factors generally eclipsed individual agency in our analysis. While indoor use was most strongly predicted by household size, tenure status, and length of residence, outdoor water use was most associated with the built environment (lot size and the presence of vegetable gardens and underground sprinklers), socioeconomic status (household income, rental status), and residents' sensitivity to lawn watering norms. Higher water prices were associated with lower water use, with lower-income households being more responsive to prices than higher-income households. Our findings have important implications for water managers and policymakers.

Evaluating the Sensitivity of Residential Water Demand Estimation to Model Specification and Instrument Choices

AbstractThere is a substantial body of work that estimates residential water demand as a function of price, household characteristics, and weather. While most results suggest demand is inelastic, researchers have found qualitatively different estimates of price elasticity—both elastic (>1) and inelastic (<1). Inconsistency in the choice of the price signal, its instruments, and appropriate weather variables across studies makes it difficult to determine if the differences in elasticity estimates are real—due to location characteristics—or an artifice of model specification. Predicting accurate demand responses to price changes enables water utilities to stabilize and anticipate future revenue while meeting conservation goals. However, specifying residential water demand with the appropriate model (under block rate structure) is challenging for three reasons: (1) uncertainty around the appropriate price signal, (2) a lack of theoretical motivation for determining which (and how) weather variables affect demand, and (3) simultaneity issues in estimation require the use of instruments, which vary across studies. Therefore, to elucidate the effects of model choices on elasticity, we use a single location and systematically vary the specification of price, instruments, and weather variables across a suite of models. We reaffirm past results that households respond to the average price. We find reasonably stable and robust estimates of price elasticity across different weather and price instrument specification—with some notable exceptions—implying that low‐cost information like average temperature is sufficient to accurately reflect the data‐generating process, reducing costs and allowing for a parsimonious model.

Advanced Control of a District Heating System with High Residential Domestic Hot Water Demand

Proper adjustment of domestic hot water (DHW) load structure can balance energy demand with the supply. Inefficiency in primary energy use prompted Omsk DH company to be a strong proponent of a flow controller at each substation. Here the return temperature is fixed to the lowest possible value and the supply temperature is solved. Thirty-five design scenarios are defined for each load deviation index with equally distributed outdoor temperature ranging from +8 for the start of a heating season towards extreme load at temperature of -26°C. All the calculation results are listed. If a flow controller is installed, the customers might find it suitable to switch to this type of DHW supply. Considering an option with direct hot water extraction as usual and a flow controller installed, the result indicates that the annual heat consumption will be lower once network temperatures during the fall or spring months are higher. The heat load profiles obtained here may be used as input for a simulation of a DH substation, including a heat pump and a tank for thermal energy storage. This design approach offers a quantitative way of sizing temperature levels in each DH system according to the listed methodology and the designer's preference.

Predicting Residential Water Demand with Machine-Based Statistical Learning

AbstractPredicting residential water demand is challenging because of two technical questions: (1) which data and variables should be used and (2) which modeling technique is most appropriate for h...

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%.

Simulating Marginal and Dependence Behaviour of Water Demand Processes at Any Fine Time Scale

Uncertainty-aware design and management of urban water systems lies on the generation of synthetic series that should precisely reproduce the distributional and dependence properties of residential water demand process (i.e., significant deviation from Gaussianity, intermittent behaviour, high spatial and temporal variability and a variety of dependence structures) at various temporal and spatial scales of operational interest. This is of high importance since these properties govern the dynamics of the overall system, while prominent simulation methods, such as pulse-based schemes, address partially this issue by preserving part of the marginal behaviour of the process (e.g., low-order statistics) or neglecting the significant aspect of temporal dependence. In this work, we present a single stochastic modelling strategy, applicable at any fine time scale to explicitly preserve both the distributional and dependence properties of the process. The strategy builds upon the Nataf’s joint distribution model and particularly on the quantile mapping of an auxiliary Gaussian process, generated by a suitable linear stochastic model, to establish processes with the target marginal distribution and correlation structure. The three real-world case studies examined, reveal the efficiency (suitability) of the simulation strategy in terms of reproducing the variety of marginal and dependence properties encountered in water demand records from 1-min up to 1-h.

Residential water demand responds asymmetrically to rising and falling prices

ABSTRACTThis paper econometrically estimates residential water consumption in Germany between 2007 and 2013 based on a panel of almost 3000 supply areas. In particular, the analysis distinguishes periods of rising and falling water and sewage water prices. The short-run (long-run) price elasticity is estimated at around 4.2% (13%), but water demand appears to respond asymmetrically to rising and falling prices. When prices are rising, the short-run (long-run) price elasticity is around 6.5% (17%). When prices are falling, the short-run price elasticity is not statistically different from zero, and the long-run price elasticity is estimated at around 12%. Additional results illustrate that employing average prices instead of marginal prices results in substantially overestimating the price elasticity. These findings are particularly relevant for utilities and regulators planning to alter the tariff structure towards a higher fixed fee and a lower volumetric fee.

Can Allocation-Based Water Rates Promote Conservation and Increase Welfare? A California Case Study

An allocation-based rate (ABR) is a special type of increasing block rate (IBR) price structure that is receiving increased attention from urban water suppliers in places like California where population growth and climate change continue to increase water scarcity. Previous work by Baerenklau et al. [Baerenklau, KA, KA Schwabe and A Dinar (2014a). Allocation-based water pricing promotes conservation while keeping user costs low. Agricultural and Resource Economics Update, 17(6), 1–14; Baerenklau, KA, KA Schwabe and A Dinar (2014b). The residential water demand effect of increasing block rate water budgets. Land Economics, 90(4), 683–699.] investigates the conservation potential of ABR and finds that consumption under ABR was 10–15% below that of a comparable uniform rate structure for a southern California case study. This paper extends that work by using the discrete–continuous choice framework to estimate household-level welfare effects of ABR for the same dataset. We find that despite the observed decrease in consumption, average household welfare actually increased under ABR due to its non-linear structure. We also find that similar results would have been achievable with a simpler standard IBR structure. While either of these block rate structures is welfare-preferred to uniform price and quantity instruments, neither clearly dominates the other.

Cross-sectional study of factors influencing the residential water demand in Bangalore

ABSTRACTThe study investigates the influences of demographic and infrastructural covariates that drive the household water demand in the 198 municipal wards of Bangalore, India. In contrast to previous studies that rely on direct household income data, this study captures the household income effect on water demand with a set of proxy income covariates such as average built-up area, proportion of households in different income categories, per capita park area, population density, road infrastructure, etc. The macro-level demand study uses cross-sectional data comprising of dependent and independent variables of 198 municipal wards of Bangalore in the month of July 2015. Linear and non-linear demand models estimate the influence of factors using the ordinary least squares (OLS) method and results are compared. Results indicate that average built-up area, proportion of high income households and per capita park area positively influence the water demand while the number of members per household negatively influences water demand.

Complements of the house: Estimating demand-side linkages between residential water and electricity

Abstract Past studies have estimated residential demand for water and electricity in isolation, but these goods are often used as joint inputs in household production activities. As such, separately estimating electricity and water demand may lead to biased demand parameter estimates. If prices are positively correlated and goods are complements, ignoring cross-price effects will exaggerate own-price elasticity estimates, leading to inaccurate revenue and conservation forecasts. Moreover, understanding the water-electricity demand relationship will allow for synergistic conservation strategies. We propose a joint estimation procedure using 3-Stage-Least-Squares-Fixed-Effects (3SLS-FE) to highlight linkages between water and electricity and conclude that water demand, in particular, appears less own-price elastic when cross-prices are included in the demand system. Results from our study region suggest that water and electricity are gross complements (with an average cross-price elasticity of approximately − 0.1 ). A simple simulation is included to highlight how omitting cross-price elasticities may lead to inaccurate forecasting and suboptimal decisions.

Voluntary Management of Residential Water Demand in Low and Middle-Low Income Homes: A Pilot Study of Soacha (Colombia)

The efficient use of water in urban contexts becomes a priority in the face of population growth and the potential vulnerability of water supply as a result of the impacts of climate change. This pilot study focuses on the use of educational strategies to promote the voluntary management of residential water demand. Three schools in the municipality of Soacha (Colombia) were involved, where students from 12 to 15 years old participated as promoters of water consumption educational campaigns within their families, covering a total of 120 low and middle-income families. Three intervention strategies (that is, a virtual platform, learning activities, and graphical tools) were carried out. The effects of these intervention strategies on changes in the water consumption were analyzed to establish the dependence of this variable with socio-demographic, economic, environmental and quality of life factors. Different information gathering tools were used, such as validated local water utility bills, surveys and self-reports. The graphical tools reduced consumption by 14%, but other strategies did not show significant reductions. However, according to self-reported data, all educational campaigns did have positive outcomes on the participants’ behavior. It was found that socioeconomic factors, such as type of housing, socioeconomic strata, living in a rented home, and quality of life variables (such as enjoying nature and culture, good and fluid family relationships, and material possessions) significantly affected the changes in water consumption behavior.

Threshold Effect in Residential Water Demand: Evidence from Smooth Transition Models

This paper aims to empirically examine the presence of nonlinear behavior in residential water demand for the case of Tunisia. We specifically explore the existence of nonlinearity with respect to the magnitude of water price changes through a logistic smooth transition regression (LSTR) framework and an increasing multi-step water pricing scheme. Using quarterly time series for the period 1980–2007 which describes residential water consumption and its main determinants, our results provide strong evidence that water consumption responds nonlinearly to the extent of price changes for the two consumption blocks considered. Water price elasticities are found to be higher when variation in tariffs surpasses a given threshold. More precisely, we find a unit elastic water demand for lower block consumers (low-income households) when price changes exceed a threshold of roughly 5%. For the upper block consumers (high-income households), water consumption is less elastic in comparison to low-income households, but still significant when the price variation exceeds a threshold of 2.6%. Our findings imply that increasing the length of the lower block of consumption may help achieve goals of social equity, while increasing tariff progressivity, at least for upper block consumers, helps promote water saving.

Spatio-Temporal Diffusion of Solar Thermal Systems in Germany: A Spatial Panel Data Analysis

Solar thermal roof-top installations offer the potential to meet an important share of residential water and space heating demand in Germany. These systems are subsidised with grants under the so-called market incentive program. The political goal is to encourage the adoption of renewable energy and to reduce CO2-emissions in the heating market in view of a low-carbon building stock. Solar thermal adoption levels are currently rather low after a high period in 2008 and 2009. Also, solar thermal adoption rates distinctly vary between regions. This paper tries to disentangle influences governing regional and temporal differences in residential solar thermal uptake. Spatial panel regression models are estimated to capture spatial interactions, while controlling for potential adoption determinants, including economic considerations, household characteristics and climatic suitability. The panel data contain observations for over 1 million solar thermal installations across 402 German regions covering the period from 2001 to 2015. Results indicate that differences in profitability influence the spatial and temporal patterns of solar thermal uptake. Regional diffusion is mainly driven by solar radiation. The development of fossil fuel prices is accountable for different adoption rates over time. New constructions do not seem to foster solar thermal use, indicating that solar heating is easily applied to existing houses. Larger households are more inclined to use solar heating, given that they use more efficiently solar generated heat. Results also show that spatial dependence drives the diffusion of solar thermal systems. These findings imply that there is potential for new policies and business models to increase the geographic and social diversification of solar thermal adoption.

Water Sensitive Urban Design Tool

The 21st century is the century of City and Urbanization. As urban communities spread and populations grow, the impact on the natural environment escalates. The hydrological cycle is among the environmental aspects most impacted by urbanization. Consequently, this study suggests a “Water Sensitive Urban Design Tool” that comprises three dimensions: (i) determining the specific issues facing residential water demand; (ii) identifying the factors influencing these issues; and (iii) the relevant water sustainability objectives and criteria. The WSUD tool could be utilized by urban designers and planners to assess the water performance of residential urban areas. It could be employed to evaluate current conditions, suggested retrofitting options, or Greenfield developments. Thus, the tool not only measures the water sensitivity of residential areas but could also support decision-making and guide development. To evaluate the suggested WSUD tool and examine its suitability to the Egyptian context, particularly the residential sector, a survey was conducted with water-related experts and design specialists. Based on the survey a finalized version of the WSUD Tool was formalized.

Electrical appliances moderate households\u2019 water demand response to heat

Analysis of potentially interconnected residential water and energy demand is sparse. In a 1-in-10 random sample of Singapore households living in apartments, water use per capita declines over the socioeconomic distribution, whereas electricity use rises. Here I show that in this leading Asian city and tropical climate, water and electricity demand respond differentially to heat across different socioeconomic groups. When temperatures rise, water demand increases among lower-income households but remains unchanged among higher-income households. In sharp contrast, heat induces larger shifts in electricity demand among higher-income households. With air-conditioner penetration ranging from 14 to 99% across different socioeconomic groups, my interpretation is that water provides heat relief for households that have yet to adopt air conditioning. How Singaporeans’ resource demands respond to heat at different income levels can inform the future responses of a vast urban population on rising incomes living in the water-stressed tropics, in similar and warming climates.

Economic development and residential water consumption in Chile

AbstractA better understanding of the relative importance of factors related to climate change and to changes associated with economic growth would serve to inform water policy and to focus scarce public resources on anticipated problems arising from distinct sources of changes in water demand. This article investigates the determinants of residential water consumption in Chile, a developing country that has seen noteworthy changes in incomes, household size, poverty rates and levels of urbanization, and which is projected to experience significant climatic but varied changes, depending on the region of the country. Panel data for 1998-2010 at the municipal level is used to analyze the sensitivity of residential water demand to climate and development-related factors. In the case of Chile, the effect on water consumption of these development-related changes is estimated to be several times that of the changes associated with climate projections for 50 to 80 years in the future.

Exploring the Statistical and Distributional Properties of Residential Water Demand at Fine Time Scales

Residential water demand consists one of the most uncertain factors posing extra difficulties in the efficient planning and management of urban water systems. Currently, high resolution data from smart meters provide the means for a better understanding and modelling of this variable at a household level and fine temporal scales. Having this in mind, this paper examines the statistical and distributional properties of residential water demand at a 15-minute and hourly scale, which are the temporal scales of interest for the majority of urban water modeling applications. Towards this, we investigate large residential water demand records of different characteristics. The analysis indicates that the studied characteristics of the marginal distribution of water demand vary among households as well as on the basis of different time intervals. Both month-to-month and hour-to-hour analysis reveal that the mean value and the probability of no demand exhibit high variability while the changes in the shape characteristics of the marginal distributions of the nonzero values are significantly less. The investigation of performance of 10 probabilistic models reveals that Gamma and Weibull distributions can be used to adequately describe the nonzero water demand records of different characteristics at both time scales.

Correction: Hou, B. et al. Conceptual Framework and Computational Research of Hierarchical Residential Household Water Demand. Water 2018, 10, 696

We wish to make the following correction to the published paper[...]

Rainwater harvesting, a measure to meet domestic water requirement; a case study Islamabad, Pakistan.

Pakistan is located in the semi-arid region of the world where water scarcity is a major issue. In such areas, rainwater harvesting (RWH) is considered to be the best alternate source of domestic water supply. Rainwater harvesting is being considered as an integral part of the sustainable water management in many parts of the world. Rainfall patterns in arid areas are typically highly variable, both spatially and temporally. Hence, there is always a need to evaluate rainwater harvesting keeping in view the seasonal variations for a specific area. In rainwater harvesting, a mechanism is designed to collect surface runoffs effectively during rainfall events from residential rooftops. In this paper, it has also been analyzed that rainwater has a great potential to be taken as a source of water demands in residential colonies of major cities like Islamabad being our study area. Here, 116 m2 (five marlas) housing pocket has been considered as a model site for which various water demands have been calculated depending upon residential needs and horticulture requirements of the study pocket. Rainwater from rooftops has been used to reduce freshwater needs of the houses. As a result, residential water demands for fresh water have reduced by almost 22% average.