Page 70 - Water Loss Control

52 Cha pte r F i v e

Top-down Component based BABE and Bottom-up analysis of real
water balance FAVAD analysis losses
(see Chap. 7 for more details) (see Chap. 10 for more detail) (see Chap. 16 for more detail)

Analyze and verify system input Determine background leakage based Create temporary sample DMAs
volume (SIV) on system specifics (miles, of mains, # representative for entire distribution
of service connections, etc.), condition system—representing areas of
of system infrastructure and average different pipe age, pipe material,
system pressure operating pressure, etc.
Standardize authorized consumption
volumes by categorizing into
• Billed authorized consumption and Determine leakage based on number Determine key components of real
its subcomponents of leaks repaired, average system losses (background leakage, losses
• Un-billed authorized consumption pressure, and awareness—location and from reported and unreported leaks)
and its subcomponents repair time for each leak based on zonal minimum night-time
flow measurements
SIV minus authorized consumption
water loss Calculate the level of real losses by
adding up all the real loss Calculate system-wide volume of real
components detailed above
losses based on sample DMAs and
Determine apparent loss volume evaluate the effectiveness of pressure
management on background leakage,
Real losses losses from leakage flow rates, and break
background leakage + losses from frequencies through field testing
reported and unreported leaks repaired
Real loss water loss − apparent loss

Hidden losses
(losses that can be reduced by active leakage control) Cross check real losses from top-
down water balance against real
Real losses from water balance − real losses from component-based losses from field measurements
BABE and FAVAD analysis

Calculate the economic optimum volume of real losses and apparent losses
(see Chap. 9 for more details)

Design the appropriate intervention program against Design the appropriate intervention program against
real losses in order to achieve the economic apparent losses in order to achieve the economic
optimum volume of real losses – optimum volume of apparent losses—
using one, all, or a combination of the four principle using one all or a combination of the four principle tools
tools against real losses against apparent losses

Intervention against real losses Intervention against apparent losses

Evaluation of results Evaluation of results

FIGURE 5.1 Water loss control program—road map. (Source: Reinhard Sturm)