Their idea is to move vast amounts of seawater along canals that would track deep into desert landmasses to create a series of connected huge inland seas measuring 30 km (18 miles) across. Small cities could then be created within the gigantic seawater “lakes,” on artificial islands.
Each seawater lake with its city would spaced apart along connecting canals measuring 150 km (93 miles) between each seawater lake city. Compared with most desert cities, in these lake cities, climate would be moderated by the body of water. The differences in thermal mass between sand and sea foster wind and even clouds due to evaporation.
A similarly massive water project initiated by Libya transfers fresh water from a distant underground aquifer. There are real sustainability issues with their plan though, because it is essentially just moving the fresh water storage from its current protected, cool, shaded, underground aquifer outside to swelter in the hot desert sun, where it won’t last as well.
By contrast, this project uses seawater, already on the surface. This is a sustainable supply of water (once developed) since it taps a replenish-able source, the ocean.
To prevent it from soaking down into the sand the water in the lakes would be retained by a continuous, two-meter-thick underground wall that reaches down to the impermeable layer, (presumably protected with rebar against earthquake).
The seawater itself in the lakes could support fish farming, which would bring a source of protein into arid deserts.
Because it is salt water, agricultural applications could use the technology pioneered by the Seawater Greenhouse which utilizes evaporation on the inside of greenhouse roofs to distill freshwater from seawater spray for use in irrigation.
Bio-energy crops could also be grown in the seawater, utilizing new and promising research involving plants that can be grown in salt water.
In exciting new work underwritten by the Masdar Institute with a desert succulent that grows in seawater, an innovative start up, Global Seawater Inc has pioneered raising a hitherto never farmed potential new bio-energy crop: Salicornia.
If cultivated in the permaculture of an interdependent mini ecosystem, Salicornia can make both bio energy and shrimp farms, while also increasing beneficial Mangrove forests, that thrive in seawater.
So, the seawater could support both Seawater Greenhouse agriculture, and energy production, fish farming, and Mangrove reforestation. Not bad! But wait, there’s more:
Between the lake cities would be 10 meter (33 feet) deep canals. At 50 meters across – 150 feet wide – barge traffic would be able to ship goods between cities at a very low carbon cost. Positively utopian!