70 



Proceedings oe the 



Estimated Monthly Discharge of Cedar Rives Near Seat- 

 tle, Washington. Drainage Area, 143 Square Miles. 



Discharge in Second feet. 



Month, 1897. Max. Min. Mean. 



January 2,812 815 1,430 



February : 2,415 823 1,303 



March 1,366 723 901 



April 2,752 790 1,599 



May 2,143 939 1.562 



June 1,410 780 1,060 



July 2,284 572 1,135 



August 561 342 427 



September 418 311 350 



October. 433 294 339 



November 3,155 323 1,318 



December 3,601 674 1,639 



Total 3,601 294 1,089 



The amount of solid matter carried by a stream 

 is a very serious problem in connection with the 

 construction of storage reservoirs thereon. The most 

 astonishing stories are told of volumes of sediment 

 carried by the rivers of southern Arizona from their 

 barren drainage basins. It is said that when these 

 floods first appear, discharged off of ranges that have 

 been travelled by the large herds of cattle in quest of 

 grass, the soil which has been exposed to the direct 

 action of the sun, being exceedingly light and dry, is 

 washed off in quantities that are enormous. In order 

 to determine the amount of silt in the Gila River at 

 The Buttes, which stream has a similar basin and 

 regimen to that of Queen Creek, the Geological Survey 

 has made observations by taking samples of the water 

 daily, and permitting the mud to settle in graduated 

 tubes. The amount of mud is then determined by 



