9 
The Oahu Water Sheds and Their Relation to the Water Supply 
of the Llonolulu and Ewa Basins. 
As to the Oahu water sheds, more can be said as to what has 
not been done than otherwise, when it comes to their protection 
and conservation for water supply. Take the Waianae moun- 
tains for instance, their present condition and what they were 
years ago when the forest extended down the slopes of the val- 
leys and ridges adjacent to the Waialua plains. 
A similar condition exists and tends to become worse on the 
slopes of the Koolau range, the backbone of Oahu, from the 
forest areas of which so much artesian water is drawn for agri- 
culture and city uses. What do we find today on these slopes 
as protective cover in place of the indigenous vegetation so 
necessary for our important water sheds? Hilo grass and scrub 
guava is practically all that remains of what was once a valu- 
able adjunct to the virgin forests which conserve our water 
supply. Even these latter, excepting perhaps sections on the 
western half of the range, are daily suffering from the hands 
of man. 
Fortunately cattle are practically excluded from the forested 
slopes in the Ewa District, and so far goats are not much in 
evidence. But what do we find in the way of forest protection ? 
The water sheds above the City of Honolulu, from Moanalua 
to Waialae, although mostly Government land are not yet even 
included in a forest reserve, anl much less are they protected 
(with exception of portions of upper Nuuanu and Makiki val- 
leys) by either the Government or private owners. So-called 
trails are being cut out of the face of the steep declivities on 
the mountains for the pleasure of those inclined to tramp, but 
outside of such pleasures no thought is taken of the forest ridges 
and wooded gorges which are simply allowed to take care of 
themselves. 
As a result of the trails cut by pleasure seekers, and of the 
depredations committed hy those apparently ignorant of the 
peculiarities of our forest growths and the disaster which fol- 
lows interference with them by man or beast, we find that 
eroded slopes caused by land slides are fast taking the place of 
what not so long ago were ideal conditions for conserving the 
precipitation. It goes without saying that the construction 
and further maintenance of trails on the steep sides of these 
mountain areas should be forbidden. Those pleasure bent, if 
