Dear John.Losses in water ...
Published by Prem Baboo, Researcher at www.researchGate.net
Dear John.
Losses in water utility operations occur in two distinctly different manners. Apparent losses occur due to customer meter inaccuracies, billing system data errors and unauthorized consumption. These losses cost utilities revenue and distort data on customer consumption patterns. Losses also occur as Real losses or water that escapes the water distribution system, including leakage and storage overflows. These losses inflate the water utility’s production costs and stress water resources since they represent water that is extracted and treated, yet never reaches beneficial use.
Real Losses, Apparent losses, Non‐Revenue Water
Different methods are available for detecting leakage such as ultrasound method.
What is Unaccounted-For-Water?
Definition
Unaccounted-for water (UFW) represents the difference between "net production" (the volume of water delivered into a network) and "consumption" (the volume of water that can be accounted for by legitimate consumption, whether metered or not). UFW = “net production” – “legitimate consumption”
Non-Revenue Water
Non-revenue water (NRW) represents the difference between the volume of water delivered into a network and billed authorized consumption.
NRW = “Net production” – “Revenue water”
= UFW + water which is accounted for, but no revenue is collected (unbilled authorized consumption).
Calculating Water Loss
Water loss is expressed as
• A percentage of net water production (delivered to the distribution system)
• As m3/day/km of water distribution pipe system network (specific water loss)
Others
m3/day/connection
m3/day/connection/ pressure
Water loss as % of net water production is the most common.
It could be misleading for systems with different net productions with same amount of real & apparent losses.
Four Components of a Comprehensive Water Loss Control Program
When considering a comprehensive water loss control program, four components are necessary:
- Leak Surveys and Leak Detection
- Speed and Quality of Repairs
- Pipeline and Asset Management
- Pressure Management