196 



windward forests of Oahu. The cliffs, steep slopes, gentle 

 reaches and valley bottoms are densely clothed with the usual 

 wet-forest cover consisting of not only the indigenous native 

 trees such as koa, ohia lehua, kukui, ohia ai, etc., but also of 

 vines, ferns, undergrowth, and mosses. The value of such a 

 cover for holding the run-off and conserving the fallen rain is 

 too well known to need further comment here, and it is especial- 

 ly important that it be protected and kept intact in this region 

 because of the high value of the pure mountain water which 

 emanates from it in various springs and streams. 



PAST HISTORY. 



Along the makai boundary of the proposed reserve there has 

 been some damage done to the edge of the forest in the past by 

 cattle with the result that the lower native forest is partly gone 

 and has been replaced to a small extent by Hilo grass and guava. 



Charcoal burners have also trespassed on the land and cut the 

 large guava trees in the main Waiahole Valley until very recently 

 when I stopped all operations and referred the matter to the 

 Commissioner of Public Lands for prosecution. The practice 

 of removing any trees here tends to favor the spread of Hilo 

 grass to the detriment of the indigenous trees and undergrowth 

 and must be absolutely prohibited. ^ 



The object, therefore, of this reserve is to put it under proper 

 forest administration and protection so that all damage by stock 

 and man will be prevented and the native forest made to serve 

 its function of conserving the water. One of the first steps along 

 this line will be the building of a stock-proof fence on the makai 

 boundary of this reserve to keep out the cattle which now run 

 at large in Waiahole Valley. 



WAIAHOLE TUNNEL. 



Waiahole is probably best known on account of the tunnel 

 which has been constructed at the head of the valley to take local 

 water and water from as far as Kahana Valley through the Koo- 

 lau Range to the cane fields in the Ewa basin. This was begun in 

 January, 1913, and completed in May, 1916, at a cost of approxi- 

 mately $2,300,000, and it is the largest hydraulic engineering 

 project ever completed in the Territory. The north portal of 

 this main tunnel, which is 2.76 miles long, is 750 feet above sea 

 level. The side tunnels which bring water from Kahana, Wai- 

 kane, Waianu and Waiahole valleys have a total length of 4.66 

 miles. 



The construction and operating of this tunnel on government 

 land was authorized on December 14, 1912, by water license No. 

 810 to the Waiahole Water Co., Ltd., issued by the Commissioner 

 of Public Lands. This license among other things authorizes 

 the company to take the government water from Waiahole and 

 Waianu valleys for which it pays the Territory annually $15,000 



