Photo by Anandan Anandan on Unsplash


Sharing our insights into the biggest sustainability challenges facing our built environment. Our previous issues of the UNSUSTAINABLE series have explored cooling, windows, concrete & cement, and steel. In this post, we explore our UNSUSTAINABLE water use and the solutions emerging to bring water systems back into balance.

Running out of water

In 2018, in the midst of a severe multi-year drought, Cape Town nearly became the first modern majority city to run out of water. Known as “Day Zero,” the city was scheduled to shut off municipal water supply, at which point its >4 million residents would have been limited to water collections just meeting minimum requirements for health and hygiene. There were even proposals to “harvest” Antarctic icebergs as an emergency freshwater resource. In the end, with water-wise behaviour along with rain, Cape Town’s Day Zero was averted. But researchers have warned that such extreme water crises could become the norm. And indeed, in the last year, droughts had global impact:

Lake Mead in 1983 vs. 2021. Source: City of Las Vegas

Billions of people are already impacted by water stress. According to the UN’s 2022 World Water Development Report, an estimated 4 billion people live in areas that suffer from severe physical water scarcity for at least one month per year (based on 1996–2005 data and representing ⅔ of the global population at the time of data collection). Yet our demand for water is only growing. Global freshwater withdrawal has grown by >6x since 1900 and is expected to grow ~1% p.a. over the next 30 years. And the mismatch between water demand and supply is only further compounded by climate change, bringing changing precipitation patterns, reduced snowpack, greater evaporation from surface water & soil, potential salination of aquifers due to rising sea levels, etc.

Water scarcity is a key challenge for our built environment. Urbanisation focuses growth in areas with often insufficient water resources, and many cities depend on long supply chains — up to 500 km — to satisfy their water needs. But as noted by World Bank, “for most large cities in the developing world, the financial means to source water from such a distance is untenable.” Water scarcity is thus a particularly challenging risk for the built environment, and as climate change and population growth add to the water supply-demand gap, cities will need to adapt to bring water systems back into balance.

Geographical limitations cities face in obtaining water. Note: MLD = million liters per day. Source: McDonald et al (2014), World Bank (2019)

Closing the gap

By 2030, there will be an estimated 40% gap between demand for water and supply if current practices continue. And unfortunately, existing measures cannot close the gap. The World Bank estimates that at the current pace of improvement in water productivity, current water-saving measures may only close a fifth of the gap. To address the rest, we need new technologies and approaches urgently. Water is the one resource that is not nice to have but a must have for us to survive.

Innovative solutions are emerging along the value chain to tackle the problem of water scarcity in a number of ways. We focus on (1) new water sources for increased water supply, (2) digital tools for more efficient water use, (3) wastewater treatment and water resource monitoring to cut down on pollution and protect our water supply.

1. New water sources for increased freshwater supplies. We explore innovations in desalination, atmospheric water generation, and water recycling.

Oneka’s wave-powered desalination buoys
SOURCE’s atmospheric water Hydropanels
Hydraloop’s smart water recycling for homes and businesses

2. Use water more efficiently to reduce freshwater demand. Over 70% of global water use is self-supplied water used for agriculture (mostly irrigation), but “farmers in most countries do not pay for the full cost of the water they use” (OECD). So our search for scalable solutions focused on industrial and municipal water users, making up 16% and 12% of global water use respectively.

Source: Data from CDP (2020)

3. Cut water pollution to protect our water supply. A staggering 50%-80% of all industrial and municipal wastewater is released into the environment without prior treatment. We scoped out PFAS removal, organic contaminant removal, and monitoring of water resources.

374Water’s compact, containerized AirSCWO system
Gybe’s water quality mapping throughout the watershed

Our 2150 take: Why now for water tech?

Historically, water tech has struggled to attract VC funding. In 2021, water startups raised an estimated $470M, just 1% of the $57B of climatetech VC & PE funding that year. The critical challenge in water is that its price doesn’t reflect its value or even its cost. Even for municipal water systems, “Full-cost charging for water services is the exception rather than the rule” (UN, 2022). According to the World Bank (2019), globally excluding China and India, water and sanitation subsidies amount to $320 billion a year, covering infrastructure costs but also operating expenditures.

But there are large and growing markets within water (overall market size estimated at ~$900B), as communities and countries become more and more water stressed, increasing water prices and driving regulation. For example:

So why now for water tech? Ultimately, necessity is the mother of innovation. When water scarcity is so severe that communities are being shut off from water supplies entirely (see here), lawmakers are considering piping water 600 miles (~1,000 km) from the Pacific Ocean to Utah (see here), the largest reservoirs in the US are nearing dead pool levels where water levels are too low to flow downstream (see here), and so much more, there is opportunity for new technology to have both great impact and great commercial potential.

Here at 2150, we see water scarcity as one of the biggest challenges of our time, and we are passionate about supporting the innovators that are reimagining our relationship with water for a more sustainable future. If you want to learn with us or if you’re creating new solutions for water security, please reach out!


2150 is a venture capital firm investing in technology companies that seek to sustainably reimagine and reshape the urban environment. 2150’s investment thesis focuses on major unsolved problems across what it calls the ‘Urban Stack’, which comprises every element of the built environment, from the way our cities are designed, constructed and powered, to the way people live, work and are cared for. Find out more at



2150 is a venture capital firm investing in technology companies that seek to sustainably reimagine and reshape the urban environment.

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2150 is a venture capital firm investing in technology companies that seek to sustainably reimagine and reshape the urban environment.