Municipal engineers are change-makers

MUNICIPAL ENGINEERS

ARE CHANGE-MAKERS

Hosted in November 2021, the annual IMESA Conference was a resounding success. Held virtually for the first time in the wake of the Covid-19 pandemic, thought leaders from South Africa and around the world presented their insights on common infrastructure challenges, showcased projects and suggested solutions on various topics.

By Alastair Currie

Opening the conference, Bhavna Soni, president, IMESA, acknowledged the unprecedented rate of change since the initial Covid-19 hard lockdown in March 2020. The overwhelming and positive response has been to rise to the challenge, embrace it, and find resilient solutions that are adaptable and implementable. That was a core focus throughout the conference, with its theme of

‘Synergy Through Engineering’.

“As engineers, we need to think differently and find visionary ways by working collaboratively through our local and international partnership network,” said Soni. “In this respect, we celebrate our IMESA alliance with the International

Association for Water, Environment, Energy and Society, commonly referred to as

IAWEES, representing some 70 countries – including South Africa – which joint ventured for the first time on our 2021 conference.”

Commented Professor Vijay Singh, president, IAWEES: “On behalf of IAWEES, we thank IMESA for the opportunity to participate and look forward to fruitful exchanges going forward. Like IMESA, our mission is to promote the advancement and exchange of knowledge for sustainable development. This is even more essential now within the context of climate change and the economic reconstruction under way following Covid-19.” These views were supported by Jean de la Harpe, executive director: Municipal Infrastructure Services at the South African Local Government Association (Salga), which endorsed the conference. “Moving into the next five-year cycle, Salga’s key focus will be on supporting municipalities to become customer-centric in terms of service delivery, leveraging off smart technologies that include self-service apps to provide intelligent billing and refined service delivery,” she explained.

Keynote address

When it comes to innovative, municipally engineered responses to unprecedented situations, the City of Cape Town’s management of its near ‘Day Zero’ drought crisis has set a new benchmark. This globally referenced case study underscores the adage that ‘where there’s a will, there’s a way’.

Conference keynote speaker, Michael Killick, director: Bulk Services – Water and Sanitation Department, City of Cape Town, showcased what resilience and adaptability really mean in practice.

The City of Cape Town currently serves some 4.5 million people, with around 6 000 connections, and some 500 000 people in informal settlements. There are six large dams, 12 water treatment plants, 24 reservoirs, and some 10 700 km of

The upgraded Seaward Road Bridge in Durban showcases innovation in municipal engineering and was the subject of a detailed paper at the conference. The project also won second place in the Engineering Excellence in Structures and Civils category at the IMESA/CESA Excellence Awards 2021 hosted during this year’s conference

pipeline all geared towards delivering around 1 400 Mℓ/day at peak production.

From the Western Cape Water Supply System, approximately 64% goes to the City, some 29% to agriculture, and the balance to local municipalities. According to the City, pure reliance on the six dams translates into around two to three years of security, dependent on predicted rainfall patterns.

During 2015 to 2017, Cape Town experienced a 1-in-590-year drought. This severe trend was highlighted in 2017 when the city experienced a 1-in-330-year drought – the worst on record in the Western Cape.

“Day Zero was a theoretical possibility – a situation where the dams could no longer supply and the taps would run dry – if the City was unable to achieve its drought restriction targets,” said Killick. “However, we did overcome what seemed an insurmountable challenge with great success.”

The best water-saving city in the world

In 2018, Cape Town was recognised as the number one water-saving city in the world. The City also won an award from the International Water Association for a 55% reduction in water demand without resorting to intermittent supply. Key success factors included consumer outreach programmes to promote water conservation, as well as technical water demand management interventions. This strategy was supported by a series of groundwater augmentation programmes, as well as desalination. Before the drought, peak demand was around 1 200 Mℓ/day, with a daily reduction target of some 500 Mℓ/day. This required the progressive implementation of water restrictions to drive this demand down.

“Our example enables other cities around the world to model and respond to climatechange-induced climate threats. Climate change studies commissioned by the City at the University of Cape Town indicate that droughts will become more regular, more severe and of longer duration,” said Killick.

“But what we don’t know is when droughts will happen and what the impact will be on Cape Town’s dams. The studies indicate a 33% probability that there will be an approximately 23% reduction in water availability in the next 20 to 30 years. Will it be a gradual event that can be planned for, or a step change? Only time will tell,” Killick continued.

Within the next years, the City’s integrated programmes are aimed at achieving longerterm water resilience, with higher assurance

As municipal engineers, we have an extra responsibility because our outcomes in terms of infrastructure service delivery are so integral to the socio-economic success or failure of the towns and cities in which we operate.”

Bhavna Soni, president, IMESA

of supply. Water sensitivity in terms of longerterm consumption is an allied goal.

Projects in the pipeline include the Berg River-Voëlvei Augmentation Scheme, which aims to add some 40 Mℓ/day; groundwater abstraction of some 100 Mℓ/day; desalination, with the potential of 50 to 70 Mℓ/day; and direct water reuse schemes, targeting some 70 to 100 Mℓ/day.

At this stage, around 2% of the City’s supply is sourced from groundwater, but that will change over time through various aquifer abstraction projects. These include the Table Mountain Group Aquifer, which will be implemented in three phases, with a final combined yield of some 45 Mℓ/day.

“Future demand management studies are crucial. In the last seven years, only one year has experienced above-average rainfall, so we need to build in an engineered reliance in response,” added Killick.

Energy

Alongside water security, maintaining and evolving the national energy grid was another major focus at the 2021 conference. Topics covered by presenters included the business case for microgrids, solar energy for desalination, and the Leliefontein Pump-As-Turbine (PAT) Station initiative at Drakenstein Municipality. Believed to be the first of its kind in South Africa, Drakenstein’s green energy innovation serves as an example for other municipalities nationally.

The final session on day three of the conference was a panel discussion, entitled ‘Can alternative energy resources result in independent municipal power supply?’

The key thrust was that renewable solutions are there to support and enhance the delivery objectives of Eskom, South Africa’s grid power utility. Some of the proposals coming forward included the need for every municipality to have an integrated energy masterplan that includes renewable energy. That could potentially lead to a national municipal renewable energy framework.

Going forward, tariff structures will be key to promoting independent power producer investment within a market that enables more open and competitive buying and selling of renewable power via a transparent energy trading platform. A key success factor here is the establishment of a national wheeling framework and a level playing field for municipalities, with the development of relevant in-house capabilities to manage and maximise alternative power. However, the overall issue remains grid stability: the ability of the national network to support and supply a national energy solution. This requires ongoing investment in the maintenance and upgrading of power transmission networks to support Eskom’s mainstream coal-fired electricity generation, and allied supplementary interventions provided by renewables.

“The complexities of our changing landscape certainly put us to the test, but the opportunities to make a lasting difference are there by adopting a participative and multidisciplinary approach to infrastructure planning and execution,” said Soni.

“On behalf of the IMESA Exco, our thanks go to the IMESA Cape Town branch, which was this year’s local organising committee. A further special thanks to our presenters and delegates for making our first virtual conference a success. We look forward to again seeing our friends and colleagues in person at this year’s 85th IMESA Conference in Gauteng. See you there,” Soni concluded.

The IMESA 2021 Virtual Conference papers can be viewed and downloaded from the IMESA website. Visit www.imesa.org.za.

‘Mossel Bay Upgrading of Informal Settlement Programme (UISP) – Emergency Shared Basic Services’ was the winner in the Community Upliftment and Job Creation category at the IMESA/CESA Excellence Awards 2021