Cause and Effect | How Cape Town averted ‘Day Zero’: A lesson for Delhi

The City of Cape Town’s experience and the decisions of its administrators could hold significant lessons for Delhi, where the past few weeks of summer have triggered an acute water shortage, triggering protests and political battles.

For Gareth Morgan, the City of Cape Town’s executive director for future planning and resilience, the “core to the crisis’ resolution” was bridging a trust deficit between the government and residents. “By demonstrating what the city was doing on its side, and by providing them with the tools and knowledge, residents were motivated to play their part,” Morgan told HT in an email interview.

The demand-supply issue

Any comparisons between the two cities need an important caveat: Delhi has roughly four times the population of the City of Cape Town. But the two face a similar predicament on a crucial aspect, that makes the lessons in South Africa relevant to India’s Capital: they both depend on their neighbours for daily water.

“96% of the water supplied to the inhabitants of the City of Cape Town comes from a regional, integrated surface water system (Western Cape Water Supply System, which is a water supply system comprising an inter-linked system of six main dams, pipelines, tunnels and distribution networks, and a number of minor dams),” Morgan explained. Groundwater within the city accounts only for the remaining 4%.

India’s national capital, meanwhile, depends on Haryana and Uttar Pradesh to meet around 86.5% of its drinking water supply.

The Yamuna, the carrier lined channel (CLC) Munak, and the Delhi sub-branch (DSB) canals from Haryana, and the Upper Ganga Canal via Muradnagar from UP, send water to nine water treatment plants around the city. The remaining 13.5% is from internal sources, primarily tube wells and Ranney wells.

In peak summer months, especially this year, the supply drops as reservoirs upstream dry up, much like what happened in the South African city in 2018.

The utility of alarm

The crisis in 2018 had in fact been brewing since 2016, which was the second year of a serious drought. That year, some consumption limits were placed, and it would not be until 2017 when the first mention of “Day Zero” emerged.

The idea behind Day Zero was simple public messaging: it represented a point in time when the city and its roughly four million people would run out of water in the municipal supply. In that eventuality, nothing short of a hard limit would come into effect, and people would only be allowed 25-litre per person per day.

“Backed by a programme of public engagement, engineering interventions and communication, the City’s primary aim was to reduce demand through water restrictions, pricing strategies and behavioural change,” said Morgan.

The single most important action, when faced with a crisis of this level, Morgan said is “demand management and associated reduction in consumption”.

“There are other measures one can take too, including pressure management and small augmentation of additional water. [But it is] important to drive down consumption by using both tariffs to price water higher for excessive consumption by households and to set targets per household.”

The Day Zero restrictions did not have to be slapped, but some tough measures were taken. A limit of 50-litre pp/day (per person per day) was imposed (for context a five-minute shower uses up to around 75-90 litres of water) and installation of water management devices was made mandatory. Differential, surge pricing for heavy users was introduced, and bans were imposed on irrigation, use of swimming pools, washing cars, and operating water fountains. Water pressure too was lowered in a bid to reduce consumption and decrease leakage.

Communication was key

“Cape Town put considerable effort into communications. It was important that we needed to explain the extent of the risk, to indicate what the City government was doing and what we needed residents to do,” he said.

The communications programme focused on educating people and normalising water-saving in day-to-day activities. These included novel methods like a daily water-use calculator to monitor usage; popularising two-minute shower songs to reduce average bath times; the coining of the slogan “If it’s yellow, let it mellow” to reduce toilet flushing; and collection and reuse of grey water from showers and washing machines for secondary applications.

Some supply augmentation initiatives included fast-tracking the use of treated water for aquifer recharge, construction of three temporary desalination plants, and 165 new boreholes to ensure supply to critical infrastructure.

These measures, Morgan said, needed cooperation from the public. “At the start many residents were resistant, but by late 2017 almost every Capetonian was playing their part. This, together with the return of some rain, enabled Cape Town to avoid Day Zero.”

What next

Crediting the residents for “saving Cape Town”, Morgan said, “The combined impact of the 2017-18 measures was a 40% reduction in water usage on pre-crisis levels, equivalent to 32 billion litres. That is a remarkable achievement.”

Behavioural change, Morgan said, was ultimately accomplished after shared responsibility was established. “Collecting, analysing and publicly communicating data helped mobilise residential and business users, and create a shared responsibility,” he said. “Residents of Cape Town now care about water, and our population is very water literate.”

Looking ahead, the City of Cape Town is working towards diversifying its water sources. Under the 2019 Water Strategy to 2040, the city is aiming for “75% surface water, 11% desalination, 7% groundwater and 7% reuse” by 2040.

A crucial big picture to keep in mind, the town planner said, was knowing when to act on a seismic campaign that requires behavioural change at a mass level.

“Knowing when to pull the trigger on an advanced programmatic response is difficult. Droughts are usual experiences in all areas of the world. But how does one know early enough that this particular drought is worse than usual? I would advise that other cities start taking action earlier [rather] than later.”

Tannu Jain, HT's deputy chief content producer, picks a piece of climate news from around the globe and analyses its impact using connected reports, research and expert speak