452 Thirtieth Annual Report 



sible to determine the extent of the unappropriated floodwaters and 

 to design engineering works for storage. Proposals for private 

 undertakings and for federal projects will no longer be confronted 

 with the impossibility of determining the extent of the available 

 water supply, and several large projects may be expected to go 

 forward rapidly. 



The state water code, in addition, makes it necessary for ap- 

 propriators to obtain a permit from the state water commissioner 

 bciore diverting water from a stream. The effect of this provision 

 is to protect those now using water in their rights. No water user 

 with established rights need fear that some new settler or project 

 will divert his water to other lands. The commissioner is given 

 authority with police powers to distribute the waters of the State 

 to those entitled to use them. Plans for dam and canal structures 

 must be submitted to the commissioner for approval, and he is given 

 authority to examine and inspect the construction, with a view 

 to securing safety of life and property on the lands below such 

 structures. 



A special appropriation is provided for the adjudication of 

 water rights in the Gila River watershed. 



CEMENT PIPE 



The results of the investigations on cement pipe made during 

 the past three years are now available in Bulletin 86. This treatise 

 covers not only the manufacture and characteristics of cement pipe,^ 

 but also reports of tests, analysis of pipe failures, discussion ot 

 applicability of cement pipe to various uses, and the design of pi])e 

 lines and pipe-line structures. 



DURABIUTY OF CEMENT PIPE 



Since the publication of the bulletin, the author has had the 

 opportunity to participate in the testing by the U. S. Bureau of 

 Standards of eight-inch cement tile of twenty different varieties 

 that had been buried in a drain in alkaline soil near Yuma for six 

 years. In most cases four tile of a series were tested. The tile 

 were excavated and were tested to destruction immediately in an 

 external pressure machine to determine the loads required to break 

 the tile. The broken segments were then examined for evidence 

 of injury by the alkali. Other specimens of the same series had 

 been removed from the ground and tested in 1914, 1915, and 1916. 

 The tests of 1919 showed practically the same or increased strength 

 as compared with the earlier tests and in no case was there evidence 

 of any disintegration. However, there was a marked difference in 



