Water users in the Nelson Mandela Bay Metropolitan Municipality have been informed of the upcoming three-month shutdown of parts of the Lower Sundays River Canal for urgent rehabilitation work.
The Lower Sundays River Canal forms part of the Lower Sunday’s Government Water Scheme (LSGWS).
The Department of Water and Sanitation (DWS), Lower Sundays River Water User Association, and the Nelson Mandela Bay Metropolitan Municipality (NMBMM) has announced that the planned shutdown of the LSGWS canal is scheduled for 10 June to 15 August 2024.
The LSGWS canal system supplies two main users with bulk water, including agricultural users, Sundays River citrus producing area, and domestic users, Kirkwood, Uitenhage, Enon, and the Nelson Mandela Bay Metro amongst others.
The LSGWS forms part of the greater Orange-Fish-Sundays Inter Basin Transfer Scheme and it transfers 740 million kilolitres of water annually from the Gariep Dam to the Eastern Cape through the 80 km Orange-Fish Tunnel.
The repair of the canal is a result of a May 2017 incident, where a section of the canal embarkment slipped, about 4.4km south of Enon.
The department then had to construct a temporary embarkment using a plastic membrane to ensure the continuous supply of water to users. However, a secondary embankment failure has occurred, with 200m downstream of the initial embankment and canal failure.
In a joint statement, the DWS, Association and NMBMM said the rehabilitation work to be carried out is critical for the reliable and sustainability of supply to users, warning that if the damaged canal is not repaired, the water scheme will be at risk of collapse.
The work on the canal includes demolishing the existing canal at the upstream and downstream tie-in sections, surface preparations, and the placement of a High-Density Polyethylene (HDPE) liner over the upstream and downstream tie-ins.
“It is important to note that during the construction of the tie-ins, the canal will not be completely shut down, but there will be intervals at which, upon completion of certain segments that are being repaired, water will be allowed to flow through to the dams to supply end users. The major domestic users to be impacted by the shutdown will be the towns of Addo, Paterson and the Nelson Mandela Bay Metro,” the statement said.
Minimising interruption
However, the stakeholders have assured the public that measures have been put in place to minimise interruptions to water supply in these areas, and Kirkwood, which is located upstream of the shutdown point, will continue to be supplied from the main canal.
The stakeholders said the Caesar’s Balancing Dam, which supplies Addo and Paterson, will be filled prior to canal shutdown, and will be continuously recharged during the intervals when the canal is opened.
They explained that the NMBM, which ordinarily receives 70% of water supply from the scheme through the Nooitgedaght Water Treatment Works, will be supplied from the Scheepersvlakte Balancing Dam for the duration of the canal shutdown period.
“The reduced supply to the Nooitgedacht WTW [Water Treatment Works] will also be offset by increased supply from the western systems through Loerie and Churchill Dams, and Loerie and Elandsjacht Water Treatment Works managed by Gamtoos Water User Association and the Metro respectively.
“The Loerie and Scheepersvlakte Balancing Dams will be filled to 100% capacity before the shutdown commences and refilled during open flows,” the statement said.
The DWS said it has consulted extensively on the planned shutdown, to bring all its stakeholders on board and for them to plan for this period and inform their customers.
“The department continues to hold meetings with these stakeholders to discuss action plans to mitigate any possible challenges and bottlenecks as the planned shutdown gets implemented,” the department said. – SAnews.gov.za
