Postponement of Lower Sundays River Canal Rehabilitation

This delay is due to the recent heavy rainfall and flooding in Nelson Mandela Bay Municipality (NMBM) that may have compromised infrastructure, including water supply systems.

The Department of Water and Sanitation has announced the postponement of the emergency rehabilitation project for parts of the Lower Sundays River Canal, which was initially scheduled to commence from June 10 to August 15, 2024. This delay is due to the recent heavy rainfall and flooding in Nelson Mandela Bay Municipality (NMBM) that may have compromised infrastructure, including water supply systems.

Reasons for Postponement

The postponement allows NMBM to:

Complete disaster assessment and response.

Resume state of readiness for the rehabilitation project.

Lower Sundays River Canal Overview

The Lower Sundays River Canal is a crucial component of the Lower Sundays Government Water Scheme (LSGWS). It supplies bulk water to:

Agricultural users, particularly the Sundays River citrus producing area.

Domestic users in Kirkwood, Uitenhage, Enon, and Nelson Mandela Bay Metro.

The LSGWS is part of the larger Orange-Fish-Sundays Inter Basin Transfer Scheme, transferring 740 million kilolitres of water annually from the Gariep Dam to the Eastern Cape through the 80 km Orange-Fish Tunnel.

Background and Scope of Rehabilitation

The rehabilitation project stems from a May 2017 incident where a section of the canal embankment slipped, about 4.4 km south of Enon. A temporary embankment was constructed using a plastic membrane to maintain water supply. However, a secondary embankment failure occurred 200 meters downstream of the initial failure.

The rehabilitation work includes:

Demolishing the existing canal at the upstream and downstream tie-in sections.

Surface preparations.

Placing a High-Density Polyethylene (HDPE) liner over the upstream and downstream tie-ins.

Water Supply During Rehabilitation

The canal will not be completely shut down during the tie-ins construction. Instead, there will be intervals where, upon completion of certain segments, water will be allowed to flow through to the dams for end users.

The canal will be closed for seven to ten days for construction and then opened for seven days to fill up dams.

Major domestic users impacted by interruptions will include Addo, Paterson, and Nelson Mandela Bay Metro.

Measures are being implemented to minimize interruptions. Kirkwood will continue to receive supply from the main canal. Addo and Paterson will be supplied from the Caesar's Balancing Dam, which will be filled prior to canal shutdowns and recharged during open flows.

Balancing Dams

Balancing dams serve as multipurpose reservoirs, used for:

Distribution points from where water is diverted.

Pumping stations or short-term storage for immediate usage.

The seven-day closure and opening intervals of the canal are based on the storage capacity of these dams.

Ongoing Consultations and Planning

The department will continue consultations to determine a new start date for the canal tie-in, ensuring all stakeholders are prepared and informed. Meetings will focus on:

Action plans to mitigate possible challenges during the planned dry period.

Emphasizing the critical nature of the rehabilitation for the reliability and sustainability of water supply.

The emergency rehabilitation is essential to prevent the total collapse of the water scheme, ensuring continuous and reliable water supply to all users.

The Department of Water and Sanitation is committed to ensuring minimal disruption and effective management during the rehabilitation of the Lower Sundays River Canal. The project, while postponed, remains a high priority to secure the water supply infrastructure for the region.