Water-Scarce
Environments

The Sahara Desert, spanning multiple North African nations, supports over 2.5 million people, primarily in oasis towns and Nile-adjacent communities. Water access in these areas depends on groundwater extracted through traditional methods such as qanats (locally known as foggaras) and deep wells, but increasing desertification continues to threaten these vital water sources.

The Sonoran Desert, straddling the U.S. and Mexico, is home to more than 4.5 million people in cities like Phoenix and Tucson. Water supply in this region relies heavily on groundwater wells and river diversions, primarily from the Colorado River. However, over-extraction, prolonged droughts, and rising temperatures have led to declining water tables, increasing dependence on deeper, often brackish groundwater sources and straining long-term water sustainability.

In São Paulo, Brazil, a city of over 12 million residents, a severe water crisis in 2015 pushed reservoirs to just 3–5% of capacity, forcing emergency rationing. The city relies on the Cantareira reservoir system, which is vulnerable to both mismanagement and climate-driven droughts, making future shortages a persistent risk.

In Cape Town, South Africa, where nearly 5 million people live, the city came within weeks of running out of water during the 2018 Day Zero crisis. The primary water supply comes from rain-fed reservoirs, which have become increasingly unpredictable due to changing rainfall patterns. In response, Cape Town has introduced desalination plants, groundwater extraction, and wastewater recycling as alternative sources. However, desalination remains costly and energy-intensive, groundwater supplies are limited by geological constraints, and outdated wastewater infrastructure hinders large-scale recycling, making long-term sustainability a persistent challenge.

Punjab, India and Pakistan, often referred to as the “Breadbasket” of both nations, provides a major share of rice and wheat production. However, 97% of Punjab’s agricultural water comes from groundwater, which is being extracted at an alarming rate. In many areas, water tables are dropping by 3 to 5 feet annually, forcing farmers to drill deeper wells—many of which now tap into brackish or saline water sources. With rainfall patterns becoming more erratic and surface water supplies inadequate, Punjab’s agricultural sustainability is at risk.