Wind driven water supply schemes require three basic items.

Sociological.
There must be a perceived need for clean potable water at the
proposed installation site. Without this need any water supply
system will fail. This is the most important rule of windmill
water supply and is the most often neglected part of the
installation process. Rule one is therefore that if the local
populace does not see a real need for clean potable water (They
will always say it is a good idea) then do not go any further.
The greatest danger signal in rural water supply is when systems
are imposed on local populaces by well wishing politicians or aid
agencies.

Wind.
Wind data is available in most parts of the world, even in remote
rural areas. Windmills can be so designed that they can pump
water in the lightest or strongest winds. In light wind areas the
cost of pumping water with windmills will increase. The
availability of wind therefore influences the cost of pumping
water with wind but not their applicability. As a generalization
windmills are most economic in areas where the wind speed exceeds
10 km/hr for a period exceeding eight hours per day.

Water.
Underground water is available in most parts of the world at
varying depths. Windmills are capable of pumping water from
surface water sources over long distances or from great depths of
up to 200 metres underground or even more with special windmill
configurations. Windmill pumping schemes should be designed so
that they never extract more than 70 percent of the tested well
yield.

If all THREE of the above are present windmills will
satisfactorily supply water. Engineers are warned to enquire
whether the sociological requirement has been satisfied.

In this guide manual a knowledge of hydraulics is assumed.
It is further assumed that if the water source is a well then the
well has been correctly drilled (Straight), cased as necessary
and tested for yield.