The City already made this case. Against itself.

Why the King David Mowbray green space matters for heat and flooding, in the City of Cape Town's own words

The strongest argument against concreting this green space is not ours. It is the City's own.

In its climate plan, in its flood policy, in the environmental assessment commissioned for this very project, and in a flagship river-restoration programme it is running right now, the City of Cape Town says plainly that open, vegetated, low-lying land like this cools the city and protects it from floods. Then it proposes to permanently dispose of 65 hectares of exactly that. Set the City's words next to the City's plan, and the contradiction is hard to miss.

First, a plain-terms reminder of what a green lung actually does, because the City's own documents take it as given.

A green lung is the city's air conditioner and flood sponge

On heat: hard surfaces, tar, concrete, roofs, soak up sunlight all day and radiate it back as heat into the night. That is the "urban heat island" effect, and it is why a built-up area runs hotter than a green one. NASA's thermal mapping has measured city centres as much as 10 degrees hotter than the green land beside them. Green space does the reverse. Leaves shade the ground, and plants release water as vapour, which absorbs heat the way sweat cools your skin. Parks and green spaces measure 1 to 7 degrees cooler than the streets around them, and that cooling drifts outward, often a hundred metres or more past the edge. A 65-hectare green lung does not just cool itself. It cools the homes and schools around it.

On water: the same open ground is a sponge. Rain soaks into soil, is slowed and stored, recharges groundwater, and is released gently instead of all at once. Cover it in buildings and parking and the rain has nowhere to go but to run off fast and hard onto everyone downstream.

Now hold the City's own statements up against the plan.

Urban heat island cross-section diagram showing temperature rising from rural areas through suburban and urban zones, with parks and ponds cooler than surrounding streets
Urban heat island effect. As land transitions from rural to suburban to urban, surface temperatures climb. Parks and water bodies (far right) remain noticeably cooler than the streets around them, and that cooling extends outward. Source: U.S. Environmental Protection Agency. Public domain.

What the City says about heat

The City of Cape Town's Climate Change Action Plan warns that heatwaves will increase in length, frequency and intensity. The City's own heat-mapping work has revealed large temperature differences between neighbourhoods, with the hottest areas being the least green. The City knows heat is coming and knows green space is the defence.

It is now proposing to give away one of the largest cooling assets in this part of the city: the very thing its own data says protects the surrounding suburbs from the heat its own plan says is coming.

NASA Landsat map of Baltimore showing land cover — dark dense urban areas, lighter suburban zones, and green forested land
Land cover, Baltimore area (2001). Dark areas are dense urban development; green is forest.
NASA Landsat thermal map of Baltimore showing land surface temperature — dense urban areas are up to 10 degrees Celsius hotter than surrounding forests
Land surface temperature, same area. Dense development runs up to 10°C hotter than the surrounding forest. Compare directly with the land cover map on the left.

Source: NASA Earth Observatory / Landsat 7, August 2001. Public domain.

What the City says about flooding

This one is the City's own admission, about this exact site. The environmental assessment commissioned for the redevelopment states that the Elsieskraal River floodplain wetland "is important in providing flood alleviation and stormwater management functions in an otherwise hardened catchment," and that increased hard surfaces from development could worsen flooding downstream. The City's stormwater policy and Sustainable Urban Drainage principles promote natural drainage, and the City concedes that the land below the 1-in-100-year floodline cannot be built on and must remain open.

So the City accepts, in writing, that this land absorbs floodwater and that hardening the catchment sends more water faster onto everyone below it. And it proposes to harden the catchment anyway. The river corridor may be left open, but ringing it with concrete is precisely the thing the City's own assessment warns makes downstream flooding worse.

The contradiction, in one programme

Here is where it stops being interpretation. Right now, the City of Cape Town is working with the C40 Cities Finance Facility on a flagship flood-resilience and river-management programme covering three sub-catchments. One of them is the Elsieskraal. The stated aim is to "improve the conditions of public open spaces and river corridors through the rehabilitation of waterways, wetlands, and floodplains," using nature-based solutions that, in the project's own words, "cool cities, purify the air, tackle biodiversity loss," restore wetlands, recharge groundwater and increase public green space.

In the Elsieskraal catchment, the City is spending international climate finance to restore floodplains, wetlands and green space. In the same catchment, it proposes to permanently dispose of and build over 65 hectares of floodplain, wetland and green space. One hand restores. The other paves. They cannot both be the right answer.

The City invokes climate change when it suits the budget

It is worth noting how readily the City uses the climate argument when revenue is on the line. During the 2017 to 2018 drought, water use fell so far that the City faced a shortfall of around R1.7 billion in its water budget. It tabled a "drought levy," a charge based on property value rather than water consumption, to recover the lost revenue. After a public backlash it was withdrawn, but tariffs themselves rose steeply through the crisis. Then the drought broke. By 2021 the dams were overflowing. The tariffs did not come back down to pre-drought levels, and when residents asked why, the City pointed to climate change: a water-scarce region, increasingly unpredictable rainfall, and the need to build resilience against future droughts.

Keeping reserves for water security may well be sensible. But notice the pattern. When climate change supports holding a revenue stream high, the City invokes it without hesitation. When climate change argues against a land disposal that would raise revenue, by removing 65 hectares of cooling and flood protection, it is absent from the reasoning entirely. The same City that tells ratepayers the climate is too unstable to lower their water bills is willing to remove the green infrastructure that helps the city absorb that instability, because this time the money runs the other way.

It cannot be both. Either the climate risk is real and consistent enough to justify keeping water charges elevated, in which case it is real and consistent enough to weigh against paving a floodplain and a cooling corridor. Or it is not. What the City should not be allowed to do is reach for climate change only when it fills the budget.

And the City protects this habitat too

The City publishes its own material on conserving the Western Leopard Toad, an endangered species endemic to these low-lying Cape Flats wetlands, which has to migrate across open ground to breed. The disposal fragments exactly the corridor the City elsewhere says it is protecting. The Full Story covers the ecological permitting implications in detail.

Cities that learned this too late

The City is not being asked to imagine the consequences. Other cities have run this experiment and paid for it. None set out to flood or bake themselves. Each made reasonable-sounding decisions to build on land that was doing an invisible job.

Houston, USA. With effectively no zoning, Houston paved over the prairie and wetlands that once absorbed its rainfall. When Hurricane Harvey stalled over the city in 2017, the water had nowhere to go and the flooding was catastrophic. Researchers identified decades of unchecked development over absorbent land as a major reason the damage was so severe, and even after Harvey the city kept approving homes in floodplains.

Chennai, India. The closest parallel to what is proposed here. The Pallikaranai marsh, a natural sponge for monsoon rain, shrank from about 2,450 hectares in 1991 to roughly 600 by 2015 as an IT corridor, housing and a rail line were built across it. In the December 2015 floods, the worst-hit neighbourhoods were precisely the former wetlands that had been converted to real estate.

Phoenix, USA. On heat, the cost is measured in lives. Maricopa County recorded 645 heat-related deaths in 2023, up from 425 the year before, and its poorest, least-treed neighbourhoods are the hottest. Where the trees are not, people die.

Jakarta, Indonesia. Decades of unregulated development, paving and groundwater extraction left the city unable to absorb rain and sinking 10 to 20 cm a year, with around 40% now below sea level. The problem became so intractable that Indonesia is spending tens of billions to relocate its capital entirely.

The decision only runs one way

None of this is an argument against housing. The city needs housing, and it can be built in many places. But a 65-hectare cooling, flood-absorbing, air-cleaning corridor cannot be rebuilt once it is covered. You are weighing homes against the climate infrastructure the surrounding suburbs rely on, at exactly the moment the city is getting hotter and its storms flashier, and against everything the City itself says it stands for.

The City should be held to its own documents.


The comment period closes 6 July 2026. Anyone can object and register as an Interested and Affected Party. One email does it: state who you are, where you live, that you object, and that you want to be registered. Send it to Development.Mowbray@capetown.gov.za and mowbray@infinity.capetown.

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All facts on this page are sourced from publicly available government documents, peer-reviewed literature, and press reporting. Sources are listed below. This site does not represent any political party or organisation.

Sources

  • City of Cape Town Climate Change Action Plan (heatwave projections)
  • City of Cape Town heat-mapping and thermal inequalities reporting (Daily Maverick, 2024)
  • King David Mowbray Golf Course Information Pack and Infinity Environmental redevelopment assessment commissioned by the City (1:100-year floodplain; Elsieskraal flood-alleviation function; downstream flooding risk)
  • City of Cape Town and C40 Cities Finance Facility, "Using nature-based solutions for flood risk management," Elsieskraal sub-catchment programme
  • City of Cape Town Western Leopard Toad conservation material
  • Cape Town drought levy and water tariff history (The Conversation, 2018; News24, 2021; MIT Technology Review, 2021)
  • NASA Earth Observatory urban heat island studies; peer-reviewed reviews of urban green-space cooling (1 to 7 degrees)
  • IUCN Red List, Western Leopard Toad (Endangered)
  • Houston/Harvey: Kinder Institute, Rice University; Georgetown Environmental Law Review
  • Chennai Pallikaranai marsh: Mongabay India; Care Earth Trust
  • Phoenix/Maricopa County 2023 heat deaths: Maricopa County Public Health; University of Arizona
  • Jakarta subsidence and capital relocation: Al Jazeera; Space4Water