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The encyclopedia · Strategy & Leadership · Operational decision · 2012–2022

Colombo cut water losses from 49% to 15% and added revenue without building new supply

An ADB program divided Colombo's leaky network into district metered areas, testing each zone until non-revenue water fell below 18%, making surplus sellable.

National Water Supply and Drainage Board

The solution

Colombo's water network, much of it from the British colonial era, leaked heavily. Surveys between 2009 and 2012 put non-revenue water in the Colombo Municipal Council area at 49% — roughly double the national average — degrading pressure, risking contamination, and forcing many households to queue at standpipes.

The National Water Supply and Drainage Board, with a $202 million ADB multitranche facility and $73 million from the Sri Lankan government, divided the network into district metered areas, replaced and rehabilitated pipes, and installed customer meters including in tenement housing that had relied on unmetered standpipes.

The program met its target of non-revenue water below 18% by 2020, and by 2022 the average was 15% across 47 fully operational district metered areas. Utility revenue rose 20%, every household in improved areas gained 24/7 pressurized supply, and roughly 85,000 cubic meters of daily surplus became saleable — worth about 3.5 billion Sri Lankan rupees a year.

Why it worked

  • District metered areas make losses visible at a scale managers can actually act on
  • Step testing fixes one section at a time, so progress is provable before moving on
  • Metering previously unmetered standpipe users converts free water into billed revenue
  • Recovered water displaces the need for expensive new production and treatment capacity
What it achievedCutting leakage is cheaper than new supplyclever

What can be applied

If a utility's own losses cap what it can deliver, recovering water it already produces can beat building new capacity: measure losses per district, then fix one bounded section at a time.

Aftermath

The program also funded staff training, a Center of Excellence, a customer call center, SCADA and energy-efficient pumps, and solar panels, which improved day-to-day operations. The utility reported significant production-cost savings even as energy tariffs rose, because far less water needed treatment and pumping. The remaining district metered areas continued to be commissioned after 2022, with metering issues being resolved zone by zone.

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