In this USD 400 million project for the National Water Supply and Drainage Board (NWSDB) in Colombo, Sri Lanka, Ceywater Consultants teamed with Nihon Suido Consultants Co. and NJS Consultants Co. to introduce district metered area (DMA) sectorization into the existing water distribution network. The project team modeled and analyzed network hydraulics, and identified opportunities to reduce non-revenue water (NRW) to 18 percent from the prevailing rate of 40 to 50 percent.
Ceywater’s team used WaterGEMS, Bentley’s decision-support tool for water distribution networks, in conjunction with the NWSDB’s GIS to model the existing network, identify optimal zones for the DMAs, and pinpoint suitable locations for new valves. GIS integration with WaterGEMS eliminated the need to feed data into the network models. It also allowed hydraulic modeling specialists and GIS professionals to work on models simultaneously, saving considerable time and reduced possible errors.
Demand allocation among the DMAs was based on prevailing water consumption rates. Low pressure zones prone to water intrusion were recommended for pipe replacement or rehabilitation. The reduction of NRW will eventually improve the NWSDB’s revenue, reduce the waste of potable water, and conserve Sri Lanka’s valued water resources. The savings realized as a result of this project will enable the NWSDB to address the demand for water among populations that have not been served previously.
The interoperability capabilities of WaterGEMS enabled the integration of the hydraulic model with an ArcGIS database. This seamless information mobility and interoperability allowed modelers to extract data from AutoCAD drawings to WaterGEMS and similarly from ArcGIS to WaterGEMS. The integration of WaterGEMS and GIS also enabled the use of existing satellite images and other GIS data for modeling purposes, minimizing the need for costly and time-consuming manual site surveys.