Sustainable solutions as cities are running out of water
It is estimated that 40 percent of the world population is already experiencing water scarcity and as the global climate keeps on warming and weirding, this situation will most unfortunately worsen and spread.
Cape Town in South Africa is just one among these cities. As a consequence of climate change, a drought has stricken the region for the past three years and the city will run out of water in just a few months. The local population will have to collect water to keep on living. Is this the new normal?
Luckily, there are many solutions, many of them very sustainable: conserving resources, fixing leaking pipes, recycling water, desalination and biogas generation.
1. Conserving water
Regular water fixtures like faucets, shower heads, toilets and urinals consume too much water. One day, future generations will gasp at the mere idea of using drinkable water to flush our crap. While other solutions are found and put in place, using so much water in the first place is sheer madness.
Fortunately, alternatives exist to slash consumption. Low-flow faucets, shower heads and toilets lead to substantial savings and the newest systems are even better. I have blogged previously about the Altered:Nozzle and the Nebia shower head and its 70% percent water usage reduction. Similarly, waterless urinals eliminate water use and can save up to a 100,000 liters per year per unit installed.
2. Fixing leaks
During my Economics class of my Sustainable MBA at Presidio, I worked with classmates on water in California. We then learned that leaking water pipings are a problem globally, with 10 to 20 percent of water flowing being lost due to leaks.
According to the local department of tourism, economic development and agriculture quoted in a local newspaper, it was estimated that a total of 7.5 million cubic metres of water was lost last year in Capetown. This would amount to 17.7 percent of total water being lost. This is a huge amount.
3. Reclaiming water
After being used, water is generally treated before it can be sent back safely to Nature, used for irrigation or landscaping. Many technologies exist to do so.
The ultimate goal of reclaimed water for cities is what has been called toilet-to-tap, ensuring that wastewater is treated in a manner that allows it to be used for human consumption again. While people can be thinking of this as gross. more and more communities are seeing this as a necessary step to be able to keep on having drinking water in the first place.
4. Desalinating water
Once water efficiency measures have been implemented on a large scale and leaks have been fixed, ocean water desalinization represents a relatively sustainable solution. With the huge amount of sun Capetown is receiving (1,700 kWh/kWp per year), having such plants run on solar, wind and energy storage is feasible. Cape Town is already building such systems but they are not ready yet.
5. Generating biogas from food waste
A lot of food is being waste worldwide and am sure Capetown is no stranger to this problem. Throwing food waste into biodigestors of all size would enable to retrieve the water in the leftovers and unsold produce. This would even generate energy in forms of both biogas and electricity. The water could be used for fertilizer for local food production.
We have seen that there are five main solutions to help Cape Town and other cities around the world to avoid running out of water: conserving water, fixing leaking pipes, reclaiming water, desalination and biogas generation.
To finance all these, a water green bond could bring massive amounts of capital from around the world. Savvy investors are looking to put more and more of their money into projects that either slows down climate change or alleviate its effects.
Image credits: Flickr, hllewellyn.