Bringing international water expertise to Sri Lanka’s capital city

Sri Lanka water supply

In such a large system, tracking down leaks can be extremely challenging.

To reduce losses from spillage and error in Colombo’s water network, NIRAS experts mapped out the system and have begun the process of identifying where issues can be found.

September 30, 2019

Every day around the world, an enormous volume of clean, potable water is wasted for the simplest of reasons: leaky pipes. In the industry, this is referred to as non-revenue water (NRW), which is produced by the water utility but lost in transit and never reaches the customer. Typically measured as a percentage of total water produced, a high NRW percentage can seriously threaten the financial sustainability of a country’s water utilities.

Sri Lanka water supply
One issue faced by the city is the age of infrastructure and lack of regular maintenance.

In Colombo, Sri Lanka, the NRW percentage is 49%. To help turn this situation around and support the government in improving their water management in and around the capital, the Asian Development Bank (ADB) launched the Greater Colombo Water and Wastewater Management Improvement Investment Programme. The project aims to improve the efficiency and financial sustainability of water supply services in the city by rehabilitating the water supply network, expanding the wastewater system, constructing a wastewater treatment plant, and reducing the amount of wasted water in the system to below 18%.

Since 2017, together with a local contractor, a team of NIRAS international experts have been working on Phase I to conduct a comprehensive review, hydraulic design, and to map the vast and complex water distribution network, a first step towards reducing NRW. Using geographic information system (GIS) software, the team reviewed the existing model, confirmed the present status of the system, and collected and analysed data on customer connections and consumption. With this wealth of information, they were able to propose how to achieve optimised efficiency in future construction.

The project will improve the quality of life for tens of thousands of residents in the greater Colombo area, including women and the poor, who will have more time for productive activities thanks to 24-hour water supply.

A kick-off meeting was held in Colombo on 19 August for Phase II of the project. This will see even more fine-grained metring devices installed, with in-depth flow measurement to assess where the water is being lost. House-to-house surveys will be conducted to find last-mile improvements that can be made. The project will wrap up in June of 2021 as years of incremental improvements will lead to a more robust system for the government and more reliable water delivery for the residents of Colombo.

62 %

targeted decrease in wasted water