136 THE FUTURE OF ARID LANDS 
areas, such as Karamoja District of Uganda, parts of Kenya and 
Tanganyika, and Northern Rhodesia and Nyasaland, the ground 
waters are usually potable, and are met commonly at depths of 
100 to 200 feet. The proportion of successful boreholes, yielding 
135 to 1,000 gallons or more per hour, commonly ranges between 
80 and go%. 
4. What Is the Practicability of Locating and Estimating Volume 
and Rate of Natural Recharge of Underground Water Supplies? As 
regards the locating of ground waters, in all the territories con- 
sidered, sites are selected on the basis of geological, topographical, 
and geophysical investigations, but in the end the actual locating 
or proving is effected by means of the drill. Water-boring opera- 
tions accordingly take pride of place in all schemes for the inves- 
tigation and development of ground waters. In the less developed 
countries Government has to take the initiative in providing 
drillers and drilling equipment, but in other countries private 
contractors are also available. Governments carry out water 
boring for the indigenous peoples as part of programs of develop- 
ment, but they drill also for European settlers on payment. 
As an example of Government drilling for the benefit of settlers 
may be quoted the following arrangements current in the Union 
of South Africa, where, however, the operations are more highly 
subsidized than in most other territories. 
Boring for water, on application by individual farmers, is car- 
ried on by the Irrigation Department throughout the Union, 
while Government subsidies are also payable on boreholes drilled 
by private contractors, where the water supplies are required for 
domestic and stock-drinking purposes. These measures have un- 
doubtedly contributed greatly to the utilization of semi-arid 
stockfarming areas and have also been a potent factor in the fight 
against soil erosion, by reducing the distance stock have to travel 
to water. There are at present 217 Government drills in operation 
and the work is heavily subsidized. 
In 1946, in order to assist stock farmers in certain parts of the 
country where arid conditions prevailed, it was decided to pro- 
claim certain areas as drilling zones, and the gradual extension of 
the areas so proclaimed has resulted in the Union being divided 
