Turn Water Losses to Gains: How District Metering Can Help Reduce Nonrevenue Water

Maynilad shares lessons from its nonrevenue water management program through training activities and plant tours. Photo credit: ADB.

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The experience of a water utility in Manila shows that dividing a large network into smaller zones improves leak detection and distribution efficiency.


One of the major challenges facing water utilities in many Asian cities is the high level of nonrevenue water. Treated water is lost in distribution systems due to leaking pipes, metering inaccuracies, illegal connections, and other reasons.

Bringing water loss levels down is expected to deliver significant benefits to both end-users and water providers, as demonstrated by success stories from Phnom Penh in Cambodia and Dhaka in Bangladesh. For the consumer, this means a continuous supply of adequate, clean, and affordable water. For the utility, recovering lost water means higher revenues and an enhanced capacity to supply quality water to customers, keep water tariffs affordable, and expand its service area.

In the Philippines, one of the water concessionaires in the National Capital Region, Maynilad Water Services, Inc. (Maynilad), achieved much success in addressing nonrevenue water by adopting a comprehensive program that focuses on capacity building of its personnel, equipment and technology upgrades, establishment and maintenance of a data management system, and facility and process improvements.

A key strategy that Maynilad employed is district metering. The main principle behind this approach is to subdivide a large network into smaller, more manageable areas.

Transforming an Aging Network

Maynilad was granted in 1997 its first 25-year concession to provide water, sewerage, and sanitation in Metro Manila’s West Zone, covering 17 cities and municipalities. It inherited an aging water distribution network spanning 3,800 kilometers.

At that time, the network served 6.1 million people through 700,000 water service connections. This represents a service coverage of 81%—of which less than half or 46% had a 24-hour water supply. There were three million people within the service area that had no access to water service from the utility.

Maynilad’s nonrevenue water was at 67%, equivalent to 1.5 billion liters of water daily, which could fill 600 Olympic-sized swimming pools. Up to 75% of water losses came from physical losses primarily because of the age and condition of the pipe network.

The company embarked on a Water Service Transformation Program in 2007, which included measures to significantly reduce and better manage its nonrevenue water. It shifted to district metering and started sectioning off its service connections into hydraulic systems and then establishing district metered areas to further segment these connections.

Advantages of District Metering

The district metered area approach in nonrevenue water management enables utilities to more accurately measure and, thus, better manage water losses. It provides the following advantages:

Develop more effective water loss interventions. By breaking down a large network into smaller and isolated district metered areas with established permanent flow and pressure monitoring points, utilities can identify the exact locations where water losses occur and enable them to better prioritize and plan water loss reduction activities and interventions.

Achieve equitable water distribution. Using disaggregated information from the district metered areas, water utilities can reallocate excess water to other areas where it is needed. They can better manage water pressure and comply with service level requirements by regulators.

Improve investment efficiency. Water utilities can leverage data and information on water service and infrastructure conditions from district metered areas as a decision support tool for prioritizing capital expenditures.


By 2022, Maynilad’s expanded network of 1.52 million service connections was segmented into hydraulic systems comprised of 20,000 to 100,000 connections and further partitioned into district metered areas with 500 to 2,000 connections.

This expanded network serves 10 million people, a 64% improvement from 2007. Water service coverage rose to 95% by 2022, with 80% enjoying uninterrupted water.

The water utility managed to reduce nonrevenue water down to 30.31%.

Table 1: Maynilad's Water Service Transformation Program

Key Result Areas 2007 2022
Population served 6.1 million 10 million
Number of water service connections 700,000 1.52 million
Water coverage 81% 95%
Coverage with 24-hour supply 46% 80.2%
Nonrevenue Water 66.8% 30.31%

Maynilad shares its experience and expertise from applying district metering through the Maynilad Water Academy. At a recent training session for Asian Development Bank staff, Maynilad experts discussed nonrevenue water assessment and management planning, meter management, establishment of district metered areas, leak detection, and the water balance framework. The training also included a plant tour of the company’s Paranaque Water Reclamation Facility, a facility that can convert treated wastewater into potable water for distribution to the main water supply network.

The academy also conducts learning activities on Basic Water Supply Operations, Basic Wastewater Management, Geographic Information Systems, Water Safety Planning, Hydraulic Modelling, and Strategic Planning for Water Districts.


Nonrevenue water management is a critical part of advancing water security and resilience.

Despite global efforts to ensure the availability and sustainable management of water and sanitation for all, water security remains a challenge. In Asia and the Pacific, around 2 billion people can be considered water insecure. This situation is further exacerbated by various factors, such as climate change and increasing water demand. The effects are very much felt in cities across the region where many water utilities struggle to provide reliable water service to an ever-increasing urban population.

Maynilad’s experience demonstrates how reducing water losses can increase a utility’s operational efficiency and ability to provide better service while reducing operations and maintenance costs and delaying capital expenditures related to the development of new water sources.

More importantly, gains from reducing water losses trickle down to end-consumers in the form of improved access to safe and affordable water.


Asian Development Bank. 2017. The Dhaka Water Services Turnaround. Manila.

Maynilad Water Services, Inc. 2023. Maynilad’s Parañaque NEW WATER Facility touted as “Water Reuse Project of the Year” at the 2023 Global Water Awards. News.

S. Park and D. McGregor. 2021. Behind Phnom Penh’s Water Success Story. China Water Risk.

Sing (Terry) Cho
Senior Urban Development Specialist (Waste Management), Water and Urban Development Sector Office, Sectors Group, Asian Development Bank

Terry Cho has over 25 years of experience in developing solid waste disposal, water supply, and wastewater treatment projects in Asia. Before joining ADB, he was a senior water and sanitation specialist at the World Bank and a senior investment operations specialist at the Asian Infrastructure Investment Bank. He also held roles in leading consulting firms where he became an international expert in water, wastewater, and waste management technologies.

Wiljeim B. Laureola
Senior Manager, Nonrevenue Water Training & Technical Operations Services, Maynilad Water Services Inc.

Wiljeim Laureola is in charge of conducting nonrevenue water (NRW) trainings for Maynilad and outside clients. He currently manages NRW teams that cater to reducing district metered area NRW levels in various business areas. Before joining Maynilad in 2008, he worked as a project engineer for several vertical construction projects, ranging from residential houses to multistory commercial buildings.

Asian Development Bank (ADB)

The Asian Development Bank is committed to achieving a prosperous, inclusive, resilient, and sustainable Asia and the Pacific, while sustaining its efforts to eradicate extreme poverty. Established in 1966, it is owned by 68 members—49 from the region. Its main instruments for helping its developing member countries are policy dialogue, loans, equity investments, guarantees, grants, and technical assistance.

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