263 



On Oahii, investigations were made on the Oahu, Waialua, and 

 Kahiiku plantations. All of the data obtained are on file in this 

 office, and are available for the public. 



United States Army Water Supply hivestigations. At the re- 

 quest of the Commanding General, Hawaii Department, U. S. 

 Army, a complete investigation of the existing and proposed wa- 

 ter supply systems for Schofield Barracks was made, and a re- 

 port with recommendations made thereon. 



Two continuous record stream measurement stations have been 

 maintained during the year by the military authorities on the 

 South Fork of the Kaukonahua Stream — the principal source of 

 supply for Schofield Barracks. These stations have been oper- 

 ated, and the records therefrom worked up into daily discharge 

 tables, by this division. 



A reconnaissance was made of the area between Diamond Head 

 and Makapuu lighthouse to determine the water in the various 

 valleys, available for military purposes, and a report was fur- 

 nished to the Chief Engineer Officer, Hawaiian Department, 

 U. S. Army. 



City of Honolulu Water Supply Investigations. A large 

 amount of surface stream and ditch flow data obtained by this 

 division in its general investigation work has been furnished the 

 Honolulu Water Commission. In addition to these the following 

 special investigations have been made : 



A careful study of the flow from the upper Punaluu valley on 

 windward Oahu. and of the U. S. Army topographic maps led to 

 the conclusion that the City of Honolulu could add about ten 

 million gallons per day of pure mountain water to its supply by 

 utilizing the Waiahole Tunnel to transmit this flow through to this 

 side of the Koolau range, in addition to the flow anticipated by the 

 Waiahole Water Co. 



Tentative and liberal cost estimates indicate that this water 

 may be delivered to an elevation of about 600 feet above sea 

 level, in the upper Nuuanu valley, at a cost of between $0.03 and 

 $0.04 per thousand gallons. The salient features of the project 

 are: 



1. A hydro-electric pumping plant in the Punaluu valley to 

 lift part of the Punaluu flow to a level sufficiently high to deliver 

 it by gravity to : 



2. A system of tunnels to deliver the waters into the end of 

 the existing Waiahole system in Kahana valley. 



3. The transmission, via the Waiahole system, of the water to 

 the Waiawa portal of the main tunnel, at a satisfactory rate of 

 payment to the Waiahole Water Company for this service. 



4. A twelve-mile pipe and tunnel line from the Waiawa portal 

 to upper Nuuanu valley. 



5. A liberal rate of payment per million gallons to the present 

 lessor of the Punaluu valley. This lease still has about forty 



