Residential end-use water demand analysis for a heterogeneous urban water and sanitation configuration in Siem Reap, Cambodia

A major limitation in planning urban water and sanitation in low- and middle-income countries is the capacity to define what services already exist in contexts that are challenging to meter. This paper demonstrates how residential water end-use analysis may be applied to model a detailed without-project situation and help to identify contextually relevant least-cost interventions. We present such an end-use analysis for a heterogeneous infrastructure configuration in Siem Reap Municipality, Cambodia. This analysis sampled end-use consumption data from 97 of 1630 geographically stratified households from 14 enumeration zones in two adjacent villages. The study represents a socio-technically diverse population accessing services from a mix of service provision types and household infrastructures at a high spatial resolution. A semi-structured survey questionnaire, observation protocol, and empirical flow measurements were used to collect end-use parameter data (frequency, duration, and volume or flow rate). Our analysis effectively disaggregates daily per capita demand for socio-demographic attributes, including income level, household size, length of tenure, different water access typologies and wastewater sinks. Bottom-up water balances of this nature provide a flexible and inclusive basis for identifying, forecasting and comparing how possible water and sanitation options may impact urban households differently in a Southeast Asian context. • Outlines a method for the social generation of residential water end-use data. • Samples from a heterogeneous urban water and sanitation configuration. • Defines a context-specific without-project case for comparing possible interventions. • Discusses how RWEUA may help to evaluate interventions in heterogeneous urban contexts. • Prompts further studies to define water end-use parameters in other LMIC contexts.