Load-shedding: Cape Town plans seven-fold budget increase to protect sewer pump stations

18 January 2023 

By June 2023, the City will have installed permanent generators at 110 priority sewer pump stations requiring generation capacity, with around 30 more ear-marked for installations. All 26 wastewater treatment plants already have permanent generators.

Cape Town has further installed early warning telemetric alarm systems at all 487 sewer pump stations to help detect faults.

As part of rapidly scaled-up budgets, over R100 million annually will go to generators and electrical maintenance to protect against load-shedding; screens to protect against foreign items in sewers; and security measures to combat ongoing theft and vandalism of critical infrastructure

Major upgrades and refurbishments to priority pump stations across the City accounts for the remainder of planned annual budgets, set to exceed R400 million by 2024.

‘While we aim to end load-shedding over time in Cape Town, we are investing now to protect our critical infrastructure from the impact of sustained blackouts. Cape Town’s sewer infrastructure is under pressure from rapid urbanisation, and in need of upgrading. One of our first actions in office was to quadruple the City’s proactive sewer pipe replacement target, from 25km to 100km annually. Now thanks to an ongoing city-wide audit of the state of sewer pump stations, we are ready to massively ramp up budgets for upgrades. This includes protection from load-shedding, sewer misuse, theft and vandalism,’ said Cape Town Mayor Geordin Hill-Lewis.

‘The City is stepping up both our pump station upgrade programme and our sewerage spill responsiveness. Interventions include more specialised vehicles, hiring additional personnel, and proactive clearing of the sewer system,’ said Councillor Siseko Mbandezi, acting Mayoral Committee Member for Water and Sanitation

Besides resilience investments in pump station infrastructure, the City is improving operations by:

- Expanding operational teams responding to pump station failures and conducting manual switching over to generators

- Procuring more specialised equipment to enhance sewer spill responsiveness, including mobile pumps and trucks with jetting and vacuum capacity to clear spills

- Proactively procuring spares annually to shorten repair turnaround times

- Cutting procurement red tape through a new ‘framework’ tender in 23/24 that will allow for accelerated expenditure

Load-shedding has major impact on infrastructure

Due to the flat terrain in most of the metro, 70% of Cape Town’s sewer reticulation network relies on sewer pump stations.

There is a high risk of these pump stations backing up and spilling if load-shedding is longer than two hours, as pump stations are generally not designed with large sumps to “store” sewage during a power outage

While the City has made significant investments in back-up generator capacity, this cannot be a final solution given the costs and high-energy demand of our facilities.

Generators also do not prevent disruptions entirely due to manual switching between supply systems. With sustained high stages of load-shedding, the switching can cause faults and often requires heavy manpower. Load-shedding may also impact on early-warning alarm systems, preventing operational teams from receiving fault alerts timeously.

Each pump station comes with its own set of specific engineering challenges that needs to be evaluated and converted to a detail solution design. For example, there is insufficient space for on-site generators in some cases, requiring alternative solutions.

The operating cost of generators is also extremely high – estimated to be R150 000 monthly per pump station. This increases for energy-intensive wastewater works, with diesel costs to run the Zandvliet plant for just 48 hours exceeding R1 million.

Plans to end load-shedding over time

Cape Town aims to provide at least four stages of load-shedding protection progressively over the next three years under the Mayoral Priority Programme to end load-shedding over time.

This is set to be achieved through various means, including:

- buying power on the open market, with the second phase of its major IPP procurement due to be announced soon

- paying businesses and residents to sell power back to the City

- incentives for voluntary energy savings under a new Power Heroes programme

- municipal generation projects such as Steenbras Hydro power, solar PV, and gas turbines

Issued by Media Office, City of Cape Town, 18 January 2023