Project: Measuring the long-term ripple effects of water and sanitation investments in Zambia

Clean water, effective sanitation, and reliable drainage systems don’t just improve health, they transform lives. In Lusaka, Zambia’s capital, the Millennium Challenge Corporation (MCC) invested in large-scale upgrades to urban water and sanitation infrastructure through the Lusaka Water Supply, Sanitation, and Drainage (LWSSD) Project. Years later, MCC turned to our team to confirm: Did these investments deliver the value that was hoped for?

Limestone Analytics conducted an evaluation-based cost-benefit analysis (ECBA) to answer that question. First, Limestone reviewed the evaluation results and the previous CBA and identified key opportunities to introduce (or backfill) key methodological and parametric changes that might affect the impacts of the investment. With MCC’s approval, Limestone then rebuilt MCC’s original economic model to reflect actual costs, outcomes, and timelines. Our team quantified benefits like time savings, reduced flood risks, and improved public health and flagged where the impacts fell short or differed from expectations. This work was conducted in close coordination with MCC’s Zambia team and aligned with the agency’s rigorous economic standards. The result was a detailed, transparent analysis of what changed and why.

For MCC, conducting an ECBA is more than just an exercise in accountability. It’s a tool for learning. By comparing projected benefits with real-world results, MCC can improve how it designs, manages, and adjusts future investments. ECBAs also reveal which assumptions hold up over time and which ones need revisiting, strengthening the agency’s evidence base for decisions across sectors and countries.

Our analysis helped clarify where the LWSSD Project achieved strong returns and where course corrections could improve future programming. It also deepened understanding of how water infrastructure shapes urban resilience and well-being.