WSDP: MODULE 3
TOPIC 8: WATER CONSERVATION AND WATER DEMAND MANAGEMENT STRATEGY
8. WATER CONSERVATION AND WATER DEMAND MANAGEMENT STRATEGY
8.1. WATER RESOURCE MANAGEMENT INTERVENTIONS
CoCT is committed to implement the previously proposed and approved WCWDM Strategy
(2007) and the newly developed WCWDM Strategy once finalised, in order to reduce the
water losses within the distribution systems as follows:
Description
GOAL A
Water Losses

Apparent Losses
(Unbilled
Unauthorised
Consumption)

Unauthorised
Consumption


Customer Meter
Inaccuracies
Real Losses

Leakage on
Transmission and
Distribution Mains

GOAL D
Leakage on
Overflows at
Storage Tanks

Leakage on Service
Connections up to
point of customer
meter
NRW (includes bad debts)

Unbilled Authorised
Consumption

Apparent Losses
(Unbilled
Unauthorised
Consumption)
Real Losses

Actual
Percentage
18.5%
Target
Intervention
>15%
7%
4%
- Meter replacement program
- Meter Audits and data cleanup
1.0%
1%
6.0%
3%-4%
Conforms to International
benchmarks. Water Audits would
be useful in reducing and
maintaining
- Water Audits
- Meter age analysis/Audits
Meter replacement Program
11.5%
11.49%
7%-8%
7%-8%
0.05%
-
0
-
23.2%
>20%
4.7%
2%-3%
7%
3- 4%
As stated in Goal A
11.49%
8-10%
As stated in Goal A
- Pressure Management
- Leak Detection
- Pipe Replacement
Monitor and respond to concerns
– pro-active maintenance and on
demand maintenance/repairs.
-
Metering and monitoring and
pro-active maintenance
Unaccounted-for water (UAW or water losses) for the period July 2010 to June 2011 stood at
18.5%. The target for 10 year Water Conservation and Water Demand Management
Strategy is less than or equal to 15% by 2015/16 according to director objectives.
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8.1.1. Reduction of Wastage
The overall target of this goal is to reduce water wastage by consumers. A number of
projects have been implemented involving promotional projects (awareness and educational
campaigns); regulation and enforcement; development and implementation of equitable tariff
structures; customer assistance towards efficient water usage (retro-fit programmes) and
targeting inefficient use within CCT operations.
8.1.2. Water resource management interventions: Situation Assessment and
Implementation progress to date
The annually average water produced in 2010/11 stood at 336.64 Mm3/y. On average, the
volume of water produced has always been greater than water supplied.
Nevertheless, water production steadily increased from 331.1 Mm3 per year in 2009/10 to
336.64 Mm3 per year in 2010/11. The average yearly volumes of water produced in 2010/11
increased by 0.04%.
The Water Demand Management Unit has initiated many projects with the intention of
reducing the water demand. In addition, most of the maintenance activities of the
Reticulation branch also have a Water Conservation/Water Demand Management impact,
for example replacing a leaking water main.
8.1.3. Targets for reducing unaccounted for water and water inefficiencies
Unaccounted-for water (UAW or water losses) for the period July 2010 to June 2011 stood at
18.5%. The target for 10 year Water Conservation and Water Demand Management
Strategy is less than or equal to 15% by 2015/16 according to director objective (see Table
2).
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8.1.4. Reducing high-pressures for residential consumers: urban
Pressure reduction (Installation of smart pressure reducing valves as well as advanced
pressure management). Reducing pressure in the network has an immediate effect on the
leakage in the system and also aids in enhancing the life of the pipe-work infrastructure.
Lower pressure reduces usage with every opening tap action in a pressure managed
network which is an immediate saving.
It has the added benefit of reducing the amount of
apparent losses that occur as a result of meter inaccuracies. The latter is due to a smaller
volume of water flowing through the meter. Overall pressure reduction reduces the overall
strain and stresses on the overall system.
8.1.5. Reducing high pressures for residential consumers: rural
The City has a very small rural component and reducing pressures here will result in an
insignificant water saving.
8.1.6. Public information and education programmes
Consumers have been made aware of the need to save water through a variety of means.
Many shopping malls have been targeted in the Metro together with the Airwave media.
Display stands have been set up at most events held around the City including during Local
Government-, Water- and Sanitation Weeks. Education institutions and schools have also
been targeted for education programmes
8.1.7. Leaks Projects
The focus here was to fix leaks in domestic plumbing on private property. The following
projects have been undertaken to date:

Fixing of leaking infrastructure (taps, toilets, cisterns) on low-income household
properties

Installation of Water Management Devices to assist consumers to manage their water
consumptions

Plumbing in low cost housing were leaks can be least afforded remains a concern, there
is a need to work close with the housing department to explore ways to improve the
pluming specification, inspections and construction supervision of pluming in low cost
housing.
8.1.8. Leak and meter repair programme: rural
See urban.
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8.1.9. Working for water programme; Removal of Alien Vegetation
The CCT has an ongoing programme for the removal of alien vegetation in the catchment
areas of their dams. This programme will have the effect of increasing available run-off.
The CCT also contributes towards the removal of alien vegetation in DWA catchments
through a catchment management charge.
The City’s Integrated Aquatic Weed Control Programme aims to assist with management of
alien aquatic weeds which occur in rivers, canals, wetlands, dams and treatment ponds.
Depending on conditions prevailing in the target water body, mechanical, manual, chemical
or biocontrol methods may be recommended.
8.1.10. Treated Effluent Re-use
Two thirds of the City’s water consumption ends up in the 24 Wastewater Treatment Works
and from there the final effluent is discharged back into the environment. The opportunity for
re-using the treated effluent has not yet been fully exploited. Thus far, the majority of Golf
Courses in the City are using treated effluent for irrigation purposes, as do parks and sport
fields. A limited number of Industries are also benefiting from the lower tariff.
Currently, approximately 12 823.16 Ml/month (November 2011, USPC Report) of treated
effluent is used. It is important to note that the volume of treated effluent use does not
directly translate into water demand savings, as not the full volume of treated effluent use
replaces potable water demand. A portion of the use replaces ground water use or in
specific cases what otherwise would be no use at all.
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8.1.11. Water resource management interventions: Future trends and goals
The WCWDM strategy is looking to further implement various programmes/interventions in
order to conserve our water resource and reduce the consumer water demand.
As the implementation of the WC/DM Strategy intensifies the assumptions will be tested and
the targets reviewed either up or down depending on the accuracy of the current
assumptions. District management areas will be implemented throughout the Council by
installing additional district meters. Leak detection activities will be intensified and a
dedicated team will soon be established.
8.1.12. Public information and education programmes
The following programmes/projects will be continued:

Aftercare Programmes & liaison

Schools training
8.1.13. Leak and meter repair programmes: urban
The following initiatives are planned for over the next two years:

Further comprehensive demand projects will be identified and rolled out over the next 5
years. In Delft, the integrated leak repair project was implemented and is now complete.

The Fix-It leak projects will continue in various areas. The Fix-It leak projects targets
high-volume consumers in low cost areas until such a time as a comprehensive demand
project is implemented.

A comprehensive debt management policy has been implemented. Part of the debt
management will be to introduce flow limiters (water demand management devices).
The debt management policy will be implemented as part of the comprehensive demand
management projects but also on an ad-hock basis for high-volume consumers in low
cost areas as part of the Fix-It leak initiative.
8.1.14. Leak and meter repair programmes: rural
Refer to 8.1.15
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8.1.15. Funding
There are a number of examples in S.A. where large industries have sponsored various
WC/WDM initiatives by Councils in order to ensure a more secure supply of water. This idea
can be expanded considerably and can be utilised to fund a number of the proposed
WC/WDM initiatives. There are also a number of foreign programmes that offer funding
opportunities. Some examples are the UN habitat programme and the African Cities Water
Conservation programme.
There are a number of private companies that are willing to enter into concessions or joint
management contracts to manage Water Services delivery or specific key performance
indicators such as the reduction of non-revenue demand.
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8.2. WATER BALANCE
By undertaking a water balance, WSAs can calculate the amount of water that is being lost
to their systems. The non-revenue water provides an indicator of how efficiently the water
supply system is being run, and provides information to the WSA on how to improve the
system. Non-revenue water is a direct loss to the WSA.
Table 1: Non-Revenue Water balance according IWA balance
Billed
Authorised
Consumption
707.46Ml/d
Billed metered
consumption
707.46Ml/d
Revenue Water
707.46Ml/d
Billed unmetered
consumption
0 Ml/d
Authorised
Consumption
750.94 Ml/d
Unbilled
Authorised
Consumption
43.48Ml/d
System
Volume
Input
921.29 Ml/d
Apparent
Losses
64.87 Ml/d
Water Losses
170.35Ml/d
Real Losses
105.48 Ml/d
Unbilled Metered
Consumption
29.67Ml/day
Unbilled Unmetered
Consumption
13.81 Ml/d
Unauthorised
Consumption
9.59 Ml/d
Customer Meter
Inaccuracies
55.28 Ml/d
Leakage on
Transmission and
Distribution Mains
105.99 Ml/day
Leakage on
Overflows at
Storage Tanks
0.45 Ml/day
Non-Revenue Water
213.83 Ml/d
Leakage on Service
Connections up to
point of customer
meter
Negligible
Note: The calculation of the IWA water balance was performed using the best available
information at present and in some cases estimation based on input from officials within
Water and Sanitation. Therefore the accuracy of the IWA water balance can still be
improved.
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Table 2: NRW Trends
Year
Overall NRW
NRW LOSSES (Ml/day)
BULK TREATED (Ml/day)
2006/7
19.36%
165.62
845
2007/8
20.22%
174.90
865
2008/9
23.30%
207.84
892
2009/10
25.37%
230.11
907
2010/11
23.20%
213.83
921
The non-revenue water has decreased from 25.37% in 2009/10 to 23.20% in 2010/11.
Note: Expressing NRW as a percentage of the system input is not encouraged as it can be
misleading as percentage figures are strongly influenced by the consumption.
Previous trends, before 2010/11, showed steady increase in the overall NRW. One of the
objectives of the strategy was to have a system in place which assesses the overall water
balance.
There is a need to develop or set a system which will aid in accurately determining and
analyses of water losses as per requirements as set out by IWA.
It is important to note that currently free basic water is about half that of non-revenue water
and close to the value water lost through real losses.
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