Sector Results and Learning:
Water, Sanitation, and Hygiene

This Water, Sanitation, and Hygiene (WASH) Sector Results and Learning page is a repository of evidence generated by all MCC-funded WASH interventions. To promote learning and inform future program design, this page captures monitoring data from key common indicators, showcases recent and relevant evaluations, includes all agency lessons from completed WASH evaluations to-date, and links to learning that has been aggregated across completed evaluations in the sector.

What Do We Invest In?

MCC has funded $1.2 billion in WASH interventions as of March 2023. These interventions fall into the following categories: water infrastructure; sanitation and/or wastewater infrastructure; hygiene and other training; and drainage infrastructure; and are often complemented by investments in policy and institutional reform.

Water Infrastructure

These programs address inadequacies in water supply, quality, or access by investing in water, sanitation, or wastewater infrastructure, and supporting utility strengthening.

Sanitation and/or Wastewater Infrastructure

These programs address inadequate access to sanitation by investing in sanitation and/or wastewater infrastructure and supporting water utility strengthening.

Hygiene & Other Training

These programs complement infrastructure investments and aim to improve hygiene and sanitary practices around water collection, storage, and use and the safe disposal of waste.

Drainage Infrastructure

These programs address excessive economic loss caused by flooding by building water drainage infrastructure.

What Have We Completed So Far?

MCC and its country partners develop and tailor Monitoring and Evaluation Plans for each program and country context. Within these country-specific plans, MCC uses common indicators to standardize measurement and reporting within certain sectors. See below for a subset of common indicators that summarize implementation achievements across all MCC WASH investments as of March 2023.


individuals trained in social and behavior change 


sanitation facilities constructed


kilometers of water pipelines constructed or replaced


millions of liters per day of water production capacity added

What Have We Achieved?

MCC commissions independent evaluations, conducted by third-party evaluators, for every project it funds. These evaluations hold MCC and country partners accountable for the achievement of intended results and also produce evidence and learning to inform future programming. They investigate the quality of project implementation, the achievement of the project objective and other targeted outcomes, and the cost-effectiveness of the project. The graphs below summarize the composition and status of MCC’s independent evaluations in the WASH sector as of February 2023. Read on to see highlights of published interim and final evaluations. Follow the evaluation links to see the status of all planned, ongoing, and completed evaluations in the sector and to access the reports, summaries, survey materials, and data sets.

Go to our List of Evaluations to see the status of MCC’s WASH sector evaluations

Highlighted Evaluations

Aerial view of the dam at Mt. Coffee Hydropower Plant, with a reservoir on one side and the St. Paul River on the other side.

February 10, 2023 | Liberia Compact

Improving water supply to the water utility in Liberia

The pipeline underperformed as the utility struggled to deliver water

  • Evaluation Type:
  • Evaluation Status: Final

MCC’s $238 million Liberia Compact (2016-2021) funded the $18 million Water Pipeline Sub-Activity, which was part of the Energy Project, to construct a raw water transmission pipeline to upgrade and replace the pre-war pipeline infrastructure. The sub-activity was based on the theory that the pipeline’s larger capacity, upstream inlet location, and gravity-fed design would increase the supply of raw water, protect against salt-water intrusion, and reduce electricity costs for the water utility. This would help meet the growing demand for water in Monrovia and improve the quality and consistency of water supplied to the utility’s service areas.

Read Evaluation Details or the Evaluation Brief

Two large water tanks behind fencing.

March 17, 2022 | Sierra Leone Threshold Program

Reforming the water sector in Sierra Leone

Water utility’s capacity increased, but financial performance is low

  • Evaluation Type:
  • Evaluation Status: Interim

MCC’s $40.5 million Sierra Leone Threshold Program (2016–2021) focused on establishing a foundation for the effective and financially viable provision of electricity and water services in Freetown. The $13.6 million Water Sector Reform Project (WSRP) aimed to improve sector coordination, strengthen commercial practices and enhance the Guma Valley Water Company’s (Guma) service provision. The $7.6 million Regulatory Strengthening Project (RSP) aimed to build the capacity of the new regulator, improve sector governance and support the long-term financial sustainability of the water sector.

Read Evaluation Details or the Evaluation Brief

A Jack resident transporting water from the communal kiosk

July 28, 2020 | Zambia Compact

Improving Peri-Urban Water Access in Lusaka, Zambia

Water access improves in peri-urban area of Lusaka but remains uneven

  • Evaluation Type:
  • Evaluation Status: Final

MCC’s $355 million Zambia Compact (2013–2018) supported private sector engagement in the water supply sector through the $6 million Innovation Grant Program. As a program grantee, MECB implemented the Smart Safe Water Supply Scheme Scaling-Up project, which aimed to save women’s time and reduce incidence of waterborne diseases for the target population by providing a reliable source of high-quality water.

Read Evaluation Details or the Evaluation Brief

May 16, 2019 | Tanzania Compact

Improving Water Supply in Dar es Salaam, Tanzania

Infrastructure investments improved reliability and quality of piped water

  • Evaluation Type:
  • Evaluation Status: Final

MCC’s $695 million Tanzania Compact (2008-2013) funded the $39.9 million Lower Ruvu Plant Expansion Activity in Dar es Salaam, which was part of the $54.6 million Water Sector Project (WSP). The objective of the project was to increase investment in human and physical capital and reduce prevalence of water-related diseases. The activity aimed to increase production and quality of water in Dar es Salaam by rehabilitating the Lower Ruvu (LR) Water Treatment Plant (WTP). The activity increased water production by 50% with the plant producing 270 million liters per day (MLD).

Read Evaluation Details or the Evaluation Brief

Go to our Evaluation Brief page to see all completed WASH sector evaluations

What Have We Learned from Our Results?

To link the evidence from the independent evaluations with MCC practice, project staff produce an MCC Learning document at the close of each interim and final evaluation to capture practical lessons for programming and evaluation. Use the filters below to find lessons relevant to your evidence needs.

  • Evaluations designs need to be adaptable as the situation on the ground shifts.

    Evaluations designs need to be adaptable as the situation on the ground shifts. This evaluation started as a continuous treatment approach using Generalized Propensity Score Matching (GPSM). At the midline, MCC realized that this was not a viable way to account for attribution of results. The design then pivoted to a binary treatment with Lower Ruvu households as the treatment group and Upper Ruvu households as the control. However, the Upper Ruvu households were contaminated by a new water treatment plant in that area. The design then pivoted again to a rigorous pre-post performance evaluation for always connected households and an impact evaluation for newly connected households, using Coarsened Exact Matching (CEM) to compare newly-connected with still-unconnected households. All of the changes to the design reflect the need for flexibility as the situation on the ground changes. In order to allow evaluations to be adaptable, MCC has internal processes such as annual evaluation risk reviews and the Evaluation Management Committee (EMC) to have cross-departmental input to inform evaluation decisions.

  • Once an evaluation methodology is agreed on in an Evaluation Design Report, the full Evaluation Management Committee must communicate continuously to ensure the design is preserved.

    Once an evaluation methodology is agreed on in an Evaluation Design Report, the full Evaluation Management Committee must communicate continuously to ensure the design is preserved. As detailed above, the project looked to invest in new areas with its cost-savings, and chose areas that were designated “controls” for the evaluation. The evaluation team learned about this decision just in time – it was very nearly too late. Communications should be clear and continuous to ensure the “too late” scenario does not occur, and MCC investments in the agreed evaluation approach are preserved.

  • Test key assumptions.

    Test key assumptions. DRWS provided hygiene and sanitation training to communities to encourage good hygiene behaviors and provide information about the new sanitation facilities. While the household survey investigated hygiene behaviors, the evaluation did not test water samples to assess the quality at the point of source or point of consumption. As such, we are not able to test the critical assumptions that the new water sources do in fact result in increased consumption of higher quality water and that households are not inadvertently contaminating water after collecting it.

  • MCC should use the findings of completed program evaluations to inform its understanding of the logic and potential benefits of similar programs in development.

    MCC should use the findings of completed program evaluations to inform its understanding of the logic and potential benefits of similar programs in development. These evaluation findings contribute to a growing body of evidence about how urban water interventions work and should help improve MCC’s design and assessment of similar interventions in the future. For example, the evaluation demonstrates that results can differ based on the customer type, e.g., new customers experienced time savings, while existing customers did not. It highlights the possibility that benefits to new customers could differ depending on whether they connect to an existing network or an entirely new network, and sheds light on other urban dynamics that should be considered, e.g., spillover benefits and the use of multiple water sources. It also demonstrates the need to plan for wastewater treatment, especially for entirely new water systems like that in Semonkong, and in cases where project benefits depend heavily on industrial water use. This planning did not happen during the design of the Lesotho project and the evaluation found that wastewater treatment was both lacking in Semonkong and a persistent constraint to industrial water use. The MCC Economist who authored the agency’s Cost Benefit Analysis Guidance for water sanitation, and hygiene, engaged on the learning coming from this evaluation and can incorporate this learning into that guidance if or when it is updated. The findings will also be available to all MCC staff and external audiences for use going forward.

  • There is value in conducting an infrastructure assessment as a precursor to measuring program outcomes.

    There is value in conducting an infrastructure assessment as a precursor to measuring program outcomes. The evaluation’s infrastructure assessment found that Mocuba emergency works were destroyed in a flood and confirmed that the Nacala works remained incomplete. As such, MCC decided not to fund data collection evaluating those investments, since it would be impossible for those investments to demonstrate benefits. Conducting the infrastructure assessment early in the evaluation prevented MCC from funding costly data collection for infrastructure which would not reap benefits.

How Have We Aggregated Learning Across the Sector?

MCC has developed a Principles into Practice paper using evidence from completed independent evaluations in the WASH sector Principles into Practice: Lessons from Evaluations of MCC Water, Sanitation, and Hygiene (WASH) Programs. The Principles into Practice series offers a frank look at what it takes to make the principles MCC considers essential for development operational in the projects in which MCC invests. The learning captured in this paper informs MCC’s ongoing efforts to refine and strengthen its own model and development practice in the WASH sector. MCC hopes this paper will also allow others to benefit from, and build upon, MCC’s lessons.