Water, water everywhere and not a drop to drink.

It's one thing to have land in the right place which is suitable for agriculture, but sometimes the water is in the area is not suitable.

Either its brackish sea water or a soda lake.

The technologies for making this water potable, suitable for agricultural use and drinking is well known yet expensive.

Desalination involves pushing brackish or sea water through a membrane. This membrane only has holes big enough to let water through. The salt stays behind. This takes a lot of energy to accomplish and that is what makes desalination a very expensive alternative.

It also takes along time to plan and build large desalination plants. They need to be customized specifically to the local water conditions, since all water, even sea water, is not the same.

Other alternatives to desalination are water reuse and using ground water. Groundwater can be problematic in brackish areas because then even the ground water may be salty. Water reuse is viable if close to a city sewage works where the water used in waterborne sewage can be extracted, purified and used for agricultural purposes.

One of the other and possibly cheapest methods is water harvesting.

Water harvesting can be accomplished by attaching gutters to any building roofs in an area. These gutters are then connected to a down pipe that empties into a large barrel or drum where rain water can be stored.

A closed drum is most effective since this prevents evaporation and keeps out insects etc.

Water harvested in this way can provide for the times between infrequent rains or add a few extra weeks of irrigation after the wet season has ended.