362 REPORTS ON THE STATE OF SCIENCE, ETC. 
Measurements 
and Records. 
Memo. 
appended. Users and Purposes. 
D (1) Surface Water Supplies for Domestic and | Gaugings and levels 
Industrial Purposes. of springs, 
Available reliable yield; droughts and streams, rivers, 
floods ; compensation water for ri- lakes and reser- 
parian interests ; and waste water. voirs ; discharges 
and overflows. 
D (2) Catchment Boards. 
Land drainage ; floods and flow control. | Ditto. 
D (3) Hydro-electric Stations. 
As (1) above, in relation to available water | Ditto. 
power for generating electricity. 
D (4) Electricity Stations. 
Feed and condensing water for steam | Ditto. 
plant ; cooling water for oil- and gas- 
driven plant. 
D (5) Canals and Canalised Rivers. 
Navigational uses and losses by evapora- | Ditto. 
tion, leakage, etc. 
D (6) Fishery and Pollution. 
Fishery interests; pollution problems | Ditto. 
and dilution of sewage and trade 
effluents. 
E Underground Water. Gaugings of springs 
Available supplies from springs, wells as (1) above ; con- 
and bores. tinuous. or peri- 
odic water, levels 
in wells and bores. 
While the amount of water required is thus increasing, and large volumes 
run to waste, unused, to the ocean, the quantity available from suitable 
sources capable of maintaining the supply through times of drought is not 
inexhaustible. "The most conveniently situated sources, whether of surface 
or underground water, have been to a large extent already appropriated, 
and it has long been recognised that a comprehensive survey of the national 
water resources is necessary to enable water conservancy to be placed on 
a basis of fact. 
Again, with regard to rivers, it is said by an American author ®: ‘ The 
damage from floods is increasing ; occasioned more by the increased occupa- 
tion of areas that are sometimes flooded than by any increase in the volume 
of flood flows. 
8 A. Hazen, Flood Flows. (Wylie & Sons, 1930.) 
