"Global freshwater use tripled during the second half of the twentieth century as population more than doubled and as technological advances let farmers and other water users pump groundwater from greater depths and harness river water with more and larger dams. As global demand soars, pressures on the world’s water resources are straining aquatic systems worldwide. Rivers are running dry, lakes are disappearing, and water tables are dropping. Nearly 70 percent of global water withdrawals from rivers, lakes, and aquifers are used for irrigation, while industry and households account for 20 and 10 percent, respectively" World's Water Resources Face Mounting Pressure
"When regular desert sand lies beneath, water bleeds endlessly downward leaving roots dry until the next watering.
With new hydrophobic sand in place, traditional watering of desert plants five or six times a day can be reduced to one watering, saving 75 per cent more water, a precious resource that is dwindling...One of the advantages of the hydrophobic sand... is that while it allows aerobic activity to move upward from the soil, it prevents underground desert salinity deposits from passing through to plant roots above; salt is corrosive and kills plants."
via nextbigfuture.com
