IRRIGATION INVESTIGATIONS ON CACHE CREEK. 



157 



In addition to the above, A. E. Chandler, of the University of California, kindly 

 furnishes the following: 



Gagings on Cache Creek, 1900. 



The two sets of gagings give a fair idea of the summer flow of the stream, and 

 the two gagings at Rumsey June 29 and August 27 show how the flow diminishes 

 as the season advances. 



In the summer of 1898 the water ceased to flow from the lake into Cache Creek, 

 and during this season the water of the lake reached the lowest stage on record, being 

 nearly li feet below the low-water mark of 1873, which up to this time had always 

 been considered the extreme of low water. 



A further stud}' of the gagings made during the summer of 1900 shows that a 

 considei-able portion of the water of this stream sinks into the coarse -giuvel which 

 has accumulated in the channel where the stream enters Sacramento Valley proper 

 and where the steep grade of the channel ends. There is here a stretch of about 7 

 miles, extending from above Capay to a point near Madison Bridge, where the bed of 

 the stream usually shows no running water after the 1st of August. Near the Madi- 

 son Bridge the stream again begins to flow, and at the Moore Dam, 4 miles below, it 

 again reaches a maximum. Below this it -sinks again. A comparison of the meas- 

 urements in the first series of gagings taken June 28 and July 3, inclusive, beginning 

 at Rumsey and extending to the canal through the sink east of Woodland, shows 

 where the losses take place when there is enough water to keep the flow in the channel 

 continuous. 



Much of the loss of water shown between the gorge above Capay and the Capay 

 Bridge occurs in the last mile. The loss from Capay down to Madison Bridge is quite 

 regular. After Madison Bridge is passed the waste is small. The sum of the vol- 

 umes in the Moore Ditch and in the stream at the Stephens Bridge maj^ be fairly 

 assumed as the flow in the neighborhood of the dam. The lo.ss between the Stephens 

 Bridge and Nelson Bridge seems quite heavy, but part of this was diverted by the 

 pumping plants which were in opei-ation along this section at the time these measure- 

 ments were in pi'ogress. The loss between Nelson Bridge and Hennigen's is not 

 great, and evaporation would account for most of this. All the water passing Hen- 

 nigen's is wasted except the small volume used for stock. Later in the season when 

 the flow is not continuous the proportion of loss at all points is greatly increased. 



For the first few miles after leaving Clear Lake the course of Cache Creek is 



