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Division of Hydrography 



Honolulu, Hawaii, October 9, 1916. 



Board of Commissioners of Agriculture and Forestry, Hono- 

 lulu, Hawaii. 



Gentlemen : — The following report of operations of the Di- 

 vision of Hydrography during September, 1916, is submitted: 



WEATHER CONDITIONS. 



The rainfall during the month was below normal over most 

 of the islands, especially in the mountains, with the result that 

 streams are at low stages and reservoirs are considerably de- 

 pleted. Heavy showers occurred during the early and latter 

 parts of the month, but these w^erc more prevalent at low than 

 at high levels. 



KAUAI RESERVOIR INVESTIGATIONS. 



During the period September 5 to 15, an investigation was 

 made to determine the possibility of storing Waimea flood water 

 at elevations exceeding 3000 feet above sea level. 



Agriculture without irrigation in the Waimea district is neg- 

 ligible, and many thousands of acres of rich lands now lie idle 

 for lack of water. 



The Waimea River discharges at times heavy floods of more 

 than six billion gallons per day. These floods cause much dam- 

 age in the lower valleys and have been the chief cause of a river 

 w-all being constructed to protect the village of Waimea.^ The 

 mean flow of the river at the point of diversion of the Kekaha 

 ditch is less than 50 million gallons per day. 



Should means be devised by which these flood waters could 

 be stored and utilized, the two-fold result of greater agricul- 

 tural output and reduced flood destruction would be obtained. 



The investigation resulted in the location of three possible 

 flood-storage sites on which, it is believed, could be constructed, 

 at reasonable cost, reservoirs having a total capacity of five or 

 six billion gallons of water. 



The stream flow records of the Mohihi, Waiakoali, Kawaikoi, 

 Kauaikinana and Kokee streams, which, with the Koaie and 

 Waialae streams, supply the Waimea River with practically all 

 of its flow, indicate that the flood flow of these first five streams 

 is sufiicient to justify the construction of these three reservoirs. 



Much more stream flow data, topographic surveys, and test 

 borings for dam sites are needed to determine the feasibility of 

 this project, and it is recommended that sufficient funds to cover 

 these investigations be included in the appropriation asked for 



