Arizona Agricultural Experiment Station 



437 



THE TEMPE DRAINAGE DITCH 



The monthly sample of water from the Tempe Drainage Ditch 

 has been analyzed as usual and results are reported in Table IV. 

 The number of samples is too few to require further discussion of 

 the changes going on in the character of this water. The object 

 of the project and results to date are given in the Thirtieth Annual 

 Report. 



.\r.LE IV. — MONTHLY VARIATION IN COMPOSITION OF WATER FROM TEMPK 



drainage ditch, parts per 100,000 



SILT CARRIED BY THE GILA RIVER 



In cooperation with the Department of Irrigation Engineering, 

 over 1100 samples of water from the Gila River were analyzed for 

 silt content. The results are intended for use in studying the 

 probable rate of silling of the proposed San Carlos dam. Inci- 

 dental to the silt determinatiot|s, total soluble solids were deter- 

 mined in all samples'and chlorides in one complete set. These data 

 will be published later. Some additional assistance was required 

 in making these analyses, the expense of which was borne by the 

 Reclamation Service. 



IRRIGATION WATERS IN SALT RIVER VALLEY 



During the past year a large number of waters from the canals 

 and from drainage wells in the Salt River Valley Project have 

 been analyzed for the Salt River Valley Water Users' Association. 

 At that time it was proposed to blend the pumped waters with the 

 canal waters in such amounts that no harm could result to water 

 users being served with the blended waters. This department 

 was called upon to pass upon the quality of the blended waters, 

 which was agreed to only under condition that certain rules would 

 be adopted and administration of these rules delegated to an expert 

 appointed by the Regents of the University and attached to the 



