Water Sector Impact Evaluation

Project Timing

March 2013 – August 2013


Water and Sanitation


Dar es Salaam and Morogoro –  Tanzania


MCA – Tanzania (Millennium Challenge Corporation)

Current Status



This impact evaluation was undertaken on behalf of the   Millennium Challenge Account Tanzania (MCA-T), part of the   Millennium Challenge Corporation (MCC) in collaboration with Social Impact, with the aim of assessing water sector projects in Dar es Salaam and Morogoro. These projects are intended to improve the supply and quality of water in the two regions, and the survey aimed to measure the impact of the water works on several outcomes of interest, such as water consumption, time spent fetching water, sources of water (domestic/commercial), water expenditures, water quality at point of consumption, incidence of water-borne disease (particularly incidence of diarrhoea among children under five years), investments in physical and human capital, time allocated within the household to productive activities, and household income.

About 5000 households were sampled across Morogoro and Dar es Salaam and an extensive baseline survey was conducted spanning both the dry and wet seasons. The Morogoro sample had an additional short survey conducted prior to the longer baseline survey. All households were sampled to continue, after the baseline, for another 3 rounds of phone surveys. This implies up to 5 rounds of data for close to half the sample. Frequent data collection is useful in order to obtain more accurate measures of water availability (as water availability varies significantly over time). Water samples were collected and tested at the household, community and system levels. Rainfall data was collected from weather stations as rainfall affects water availability. Monthly reports were also obtained from the public utilities, to provide supplementary data. Finally, the survey included a qualitative component in both the survey regions, with focus group discussions and structured interviews being conducted among a range of relevant water users and suppliers, such as female water users in low-income areas, water-related business owners, various types of water sellers, community managed water source operators, and district health and education officers.

The project will exploit differences in treatment exposure across households to measure the effects of the programme. Because treatment exposure will not be random Generalised Propensity Score Matching (GPSM) and Difference-in-differences (DD) regressions will be used to control for observables that jointly determine treatment and outcomes. A secondary identification strategy is to use distance to the distribution network as an instrument for treatment


Baseline Results were presented in Dar es Salaam in July 2014.  MCC have published the final report and project materials here.