by Robbert van der Bij
From 11 to 21 February 2019, Reint-Jan de Blois – NRW expert from VEI – visited 3 WaterworX partners in Cali and Neiva Colombia. We supported the 3 water companies in quantifying physical and commercial losses with billing system (top-down) and field measurement (bottom-up) data. We addressed several organizational and technical challenges that partners will work on in the coming period.
Reint-Jan, for example, coached the NRW Team in Las Ceibas in utilizing existing telemetry (24/7 flow and pressure measurement) to quantify the physical (leakage) losses with Minimum Night Flow data. These losses were unrealistically high, suggesting that the DMA was not yet fully isolated. That evening, the NRW team engineer and technician inspected the valves with a leak noise pen and confirmed that they were ‘leaking’ water to the neighboring DMA. Actions to address (service/replace) or measure this flow (temporary ‘ultrasonic’ flow meter) will be implemented in the coming weeks to reliable establish the physical/commercial losses and prioritize appropriate measures accordingly.
The Management Team of our other partner, Acuavalle, agreed to appoint a dedicated NRW team to fast track the implementation of prioritized NRW reduction activities. A GIS-based Digital Elevation Model is currently being used to assign elevation coordinates to the distribution network in Epanet (hydraulic model). The model will be calibrated with field-based flow and pressure measurements and guide the delineation of pressure-zone based DMAs. Incoming lines to high pressure areas (and proportional leakage volume) losses will be fitted with Pressure Reducing valves to reduce water wastage (costs). An ongoing meter replacement program will address commercial loss and increase sales.
Finally, Aguas del Huila worked on a strategy to identify and separate a secondary pipeline network with untreated water from the potable water supply through a door-to-door survey to identify double connections and non-return valves to prevent return flows through the meter. In a nutshell, very important steps have been taken in the last two weeks.
The WaterworX project in Colombia consists of a partnership between three local Colombian companies. Acuavalle - a regional watercompany - providing water to 750.000 Colombians. Las Ceibas - the public service company for the city of Neiva - a city of 450.000 inhabitants. And finally Aguas del Huila - a regional planning bureau with limited operations - who we are helping to grow their operations to guarantee safe and affordable drinking water to ca. 200.000 people.