the WAS effectively makes this water saving sustainable over the long
run. LORWUA is one of the bigger
irrigation schemes in South Africa
that delivers water on demand to
over 1 000 abstraction points on a
canal network to irrigate a total
area of 9 510 ha. Water is ordered
and released on a weekly basis from
the Clanwilliam dam into the
Bulshoek dam and then into a 90
km main canal with secondary canals for distribution on a weekly
basis. See Figure 3
Lower Olifants River Water Association is situated in the Vredendal
area, Western Cape Province and
the main sources for providing water to the irrigation scheme are the
Bulshoek- and Clan William Dams.
The irrigation scheme is sub divided
into eight wards. The main canal
splits into two branch canals namely the left bank, which is 136km
long and the right bank canal
which is 123 km long. The scheme
has a total of 1 052 sluices to provide water to a scheduled quota of
12 200(m3/ha)/annum. This translates to a volume of 122 million m3/
annum. Despite climatic challenges
and challenges associated with the
operating of an 80 year old irrigation scheme, LORWUA is continuously striving to improve water use
efficiency. The Water User Association has gone out its way to ensure
that not a drop of water on the
scheme is wasted unnecessarily.
By recognizing the need to optimize
their water use they are maintaining the water conveyanc e system,
ensure accurate and real time collection of water data and empowering the water control officers to
ensure better scheme management.
LORWUA introduced various interventions through the form of technical, social, financial and institutional measures to improve their
water use efficiency.
The interventions included the
following:
Implementing the Water Administration System (WAS) program;
Installation and maintenance of
an extensive telemetric flow
measurement system to monitor
and audit the water delivery;
Automated releases from
Bulshoek Dam where a specific
discharge rate is set;
Introducing the ‘name and
shame’ rule. Those found taking
more than their share can have
their sluices painted red for all to
see;
Better management procedures
for water control officers and
water control aids;
Continuous maintenance and
repair work to the water distribution structures and canals;
and
The using if a professional diving
team to undertake repairs to the
canal system while water is running.
Through the implementation of the
above-mentioned interventions,
LORWUA has managed to reduce
water losses from 48% (in 2002) to
24,6% currently. Lower Olifants
River scheme remains an important
example of effective water management to achieve water savings in
the irrigation sector.
Figure 3 Clanwilliam dam, Bulshoek dam and main canal