IRRIGATION FROM SAN JOAQUIN KIVER. 219 



and come to the level of the great plain only when nearing the trough of the valley. 

 At this point in their course thev turn northward and unite with the main stream^ 

 some as distinct branches; others, as in the case of the smaller ones, through swamps, 

 sand-flat deltas, or overflowed tracts. 



Those named below are the principal streams flowing down the east side of the 

 valley, as enumerated from the northerly end, with the drainage area of each given. 

 The streams marked with an asterisk derive their waters largely from the melting 

 snows of the high Sierras. These snows are substitutes for extensive storage reser- 

 voirs, and slowly yield their waters throughout our early springs and summers — the 

 irrigation season — in an unfailing supplj' of irrigation water. The remaining streams 

 of the list have their sources in the nearer mountains and foothills, and are replen- 

 ished by rains rather than by melting snows, and in consequence are torrential io 

 character, intermittent in flow, and less reliable for purposes of irrigation. 



Tributaries of the San Joaquin River, wilh their drainage areag. 



Square miles. 



Consumne Kiver * 589 



Dry Creek 208 



Mokelumne River * 573 



Calaveras River * 390 



Stanislaus River * 971 



Tuolumne River* 1, 514 



Merced River * 1, 072 



Bear Creek 153 



Mariposa Creek 96 



Chowchilla Creek (or river) 272 



Fresno Creek (or river) 258 



San Joaquin River * -. . 1, 637 



Kings River* 1,853 



Keweah River 608 



Tule River 446 



Deer Creek 130 



White River 96 



Posa Creek 278 



Kern River* 2,382 



Caliente Creek 461 



Numerous small streams 2, 138 



Total area of mountain and hill drainage 16, 135 



On the western slope of the San Joaquin Valley the streams originate in the Coast 

 Range of mountains. Thej' are torrential and intermittent in chai-acter. The stream 

 beds carry water but a few hours or daj^s after i-ainfall, and this water spreads over 

 the upper plain, seldom reaching the San Joaquin. The streams are limited in sup- 

 ply and unreliable for irrigation.' 



From PoUa^ky for a distance of 40 miles downstream the river winds along 

 through low. fertile, and productive bottoms, shut in by blufl's, with hills behind 

 them. The river gorge in this length varies from a mile to a half mile in width. 

 Behind the bluffs and hills are elevated plains. These bluffs diminish in height above 

 the river from 75 feet near Pollasky to 40 feet at Herndon, and finally disappear at 



nVilliam Hammond Hall. 



