274 

 Dl\ISIOX 01-' HYDROGRAPHY. 



Honolulu, August 15. 1*)13. 



Board of Commissioners, Agriculture and Forestry. 



Gentlemen : — The following" report of operations in the Divi- 

 sion of Hydrography for July, 1913, is submitted: 



G. K. Larrisoii, Siipcrinteiidciit : 



(Jn July 1 and 2 a reconnaissance, which was begun on June 

 30, was made of the Kahana, Waikane. L'wau, Waianu and W'ai- 

 ahole valleys on windward Oahu, and the Waiawa valley in cen- 

 tral Oahu. All streams in these valleys are being rated by weirs 

 by the W'aiahole Water Company. Current meter measurements 

 were made to check the weirs, which were fountl to give dis- 

 charges from ten to fifty per cent, too high. The weirs were 

 found to be in poor condition, with leakage, high velocity of ap- 

 proach, and with Ijlunt uneven crests. One daily reading was 

 being made at each station except on Sundays. The condition 

 of these stations was reported to the chief engineer of the Waia- 

 hole Water Company. It is possible that a number of clock regis- 

 ter stations will be established by the company, to be maintained 

 and operated by this office. 



On July 9th, Messrs. Dort, White and the untlersigned made a 

 reconnaissance to develo]) a direct trail between the stations on 

 the north and south forks of the Kaukonahua streams. The trail 

 was broken through from the south fork to within a sliort dis- 

 tance of the north fork stations, but the attem])t was abandoned 

 on account of topographical difficulties. 



On July 10 a reconnaissance was made, in com])an\- with the 

 Superintendent of h'orestry and the chief engineer of the llishop 

 Estate, of the lower Kawailoa region. 



On July 19, accompanied by Air. H. Kimble, assistant engineer, 

 the writer sailed for Kona, Hawaii, and the balance of the nidnlh 

 was s])ent on a field reconnaissance in that district. 



The balance of the uKjnth was spent in general administration 

 wf)rk. 



J. C. Port. Office lin-iuccr, Oahu: 



On July 1 the rain gages on Konahuanui, 3100 feet ; .Ml. ( )lym- 

 pu.s, 2440 feet, and Kaau Crater, 1700 feet, were read. 



On July 9 a trail reconnaissance between the south and north 

 forks of the KaukDnahua was made. 



f )ii Inh- 14 ;i silt' was selected fur the Kalilii stream gaging 

 station at an elevation of ;il)out .^00 feet .'iliove the sra level. This 

 stream will ])rol)abl\- be utilized to augment 1 lonolnlu's water 

 supply. 



