Nature-Based Solutions Could Protect Cape Town’s Water Supply
In early 2018, the name Cape Town became synonymous with water scarcity after a three-year drought drew the city dangerously close to “Day Zero”—the day when the citizens’ taps would run dry.
While that doomsday was postponed—due to strict water-use restrictions, cutting irrigation water to agriculture and pumping in extra water—it is only a matter of time before it’s on the horizon again. With steady population growth and the realities of climate change, water demand is predicted to outstrip supply in the Greater Cape Town Region by 2021. In addition, less water is reaching the reservoirs that feed the city because of watershed degradation and invasive plant species.
The Greater Cape Town Water Fund Business Case—released on Nov. 16, 2018—shows that nature-based solutions could help ensure the city has the water it needs for its citizens, businesses and the economically important agricultural sector.
What Is a Water Fund?
While the current global focus has been on “grey” infrastructure—such as desalination, recycling waste-water and tapping groundwater supplies—to combat water scarcity, “green” solutions have the potential to produce significant water supply improvement at far lower cost.
Water Funds are public-private partnerships that connect around a common goal: using nature-based solutions to ensure sustainable watershed management. Downstream users, such as businesses, utilities and local governments, contribute to upstream conservation initiatives aimed at improving water quality and quantity for the region.
The Nature Conservancy (TNC) has helped establish more than 35 water funds worldwide since 2001, including the Upper Tana-Nairobi Water Fund—the first in Africa—in 2015.
What’s Happening in Cape Town?
Healthy watersheds naturally store, filter and transport rainfall to rivers and dams. But in the Greater Cape Town Region, thirsty invasive plants—including acacia, pine and eucalyptus — have been sucking up huge amounts of water, reducing the amount available for people in and around Cape Town.
How much water could these plants really be drinking?
The Greater Cape Town Water Fund Business Case reveals that alien plant invasions are stealing 55.4 billion liters (or more than 15 billion gallons) of water a year an amount that could otherwise supply the city and its environs for two months. In a region where every drop counts, those losses are significant.
Restoring watersheds and removing invasive plants could release 55.6 billion liters of extra water per year, compared with a "business-as-usual scenario" in which invasive plants continue to take over by the sixth year. By 2045, after 30 years of maintenance and preventing new invasive plants from growing, the amount of extra water could go up to 100 billion liters, equivalent to one-third of Cape Town’s current annual supply. Leading grey infrastructure alternatives cost between five and 12 times as much, and none produces as much extra water.
Nature-based solutions have many other benefits, as well.
The Cape Floral Region holds more than 20 percent of Africa’s plant life, and 70 percent of the plants here are found nowhere else on Earth. Unmanaged invasive plants can quickly replace other species and threaten this native plant life. They also alter soil ecology and increase the frequency and severity of wildfires.
By keeping invasives in check, we can help protect this ecologically unique habitat.
TNC has spent more than two years working with partners laying the groundwork to establish the Greater Cape Town Water Fund. This has included a pilot invasive species removal program in the Atlantis Aquifer, a key source of water for the region.
The Greater Cape Town Water Fund Steering Committee can now use the results of this study to develop—along with other stakeholders—a restoration strategy for seven sub-catchments identified as priorities in the Business Case.
With an investment of just $25.5 million dollars, the Greater Cape Town Water Fund can help create a healthier, more water-secure future for the Cape Town region.
Greater Cape Town Water Fund Steering Committee:
The Nature Conservancy, National Department of Water and Sanitation, National Department of Environmental Affairs (Environmental Programmes), Provincial Department of Environmental Affairs and Development Planning, City of Cape Town, South African Biodiversity Institute, CapeNature, Coca-Cola Peninsula Beverages, Nedbank, Remgro Ltd, and WWF.
Special Thanks to Our Generous Supporters:
PepsiCo, The Coca-Cola Foundation, Caterpillar Foundation, and Levi Strauss & Co.