WATER SOIT.S. 1019 



WATER SOILS. 



River and artesian waters, U. II. P\)i;i?ks {Arr-oiui Sfa. Uj>i. IDOO^ 

 jyp. ISO-lSJf). — Till' results are reported of dctorniiiiatioiis of silt, 

 alkali salts, and iiitrouen in representative sann)les from a How of one 

 week, both high and low water, of the Colorado at Yuma, the Gila at 

 Florence, and the Salt River at Mesa City; also of a canal taking water 

 from the lower Cxila, as well as of alkali salts in 9 samples of w^ater 

 from artesian wells on the eastern slope of Graham Mountain al)Ove 

 Satford, Thatcher, and Pima and in the San Pedro Valley south of 

 Benson. The analyses reported show that the ?> principal rivers of 

 the Territory are *'of ({uite variable character for irrigatino- purposes, 

 containino-, in the instances mentioned, from 5<» to 200 parts of soluble 

 salts in liKt.OOO, in round mimbers.'' 



" Tlie (luantity of soluble salts is influenced by the stage of water and b}' seepage 

 fniin irrigated districts. The nature of these salts is influenced by the same causes. 

 The Colorado River is less saline the year around than either the Salt or the Gila. 

 Ill summer, when its waters rise under the influence of the melting snows in Colo- 

 rado and Utah, tlie tcjtal solu1)k' solids were observed to average as low as 25 parts 

 ill 100,000 for months at a timr. 



"Flood waters in all cases not only carry less salts but more silt, including nitrog- 

 enous fertilizing materials. Barring the inconvenience of excessively muddy water, 

 tliei'efore, flood waters are in every way preferable for irrigating purposes. 



"The average amount of silts in the Salt River supply from August 1, LSOO, to 

 August 4, 1900, was by weight 0.1 per cent of the water; by volume, 0.:i percent. 

 Tliis amount of silt is unquestiona))ly less than the average on ac(X)unt of the unusu- 

 ally low water prevailing during most of the time of sampling. The Salt River, 

 ho\ve\er, is undoul)tedly far less silty than the Gila, and this element of doubt in 

 connection with the life of reservoirs correspondingly less. . . . 



" The average total nitrogen in the Salt River supply for one year was found to be 

 :>.L'ri ])arts in 1,000,000 of water, including that which was containcil in the silt. Of 

 this amoimt 1.04 parts per million existed in the form of nitrates." 



The analyses of the artesian waters show that while the total soluble 

 stilts are not excessive, sodium carbonate is uniformly present, \iiry- 

 iny- ill different cases from 3.4 to 19.6 parts per hundred thousand. An 

 antdysis of an alkali crust from the region in which some of the 

 tirtesiiui wells are located shows that a considerable jmiount of cal- 

 cium sul))hate is present. "'Should the soils of this region prove to 

 conttun calcium sulphate generally, the alkalinity of the artesian wells 

 will, at least for a time, be rendered harmless thereby." 



A preliminary report on the artesian basins of Wyoming, W. C. 

 KNI(;nT( WyoniriKj Sf((. Bnl. J/>. pp. 107 -i-') I ^ ph. J6', nidp I). — This is 

 a preliminary treatise on the geology and artesian basins of Wyoming, 

 tnised upon field notes collected during the past four yetirs, accompanied 

 by a m:i}) embodying '"idl thtit is known of the geology of ^\'yoming 

 up to date," the object of the })ublication being to (»xj)lain th(^ essential 

 features of the artcsiiin basins of the State, so thtit artesitui wells mtiy 



