WATER LOSSES PRO"M WET AREAS 



77 



PLATE XII 



Lotver bench of Mojave Rive 



Direction of flow. 



\ 



\ 



^'#.'" 



- X %- 



_\_.. 



eal-e 



Swamp 



Water line at \ 

 edqe of sm/an^p^ 



I C ■ 



Thermomefer'i 

 shelter I 



^ 



-X X X X 



Ram < 



Supply Ta nk . 



Ground wsten 



; A \ 



Tank NO I. , y 



PLAN OF VICTORVILLE STATION. 



values of which are difficult to determine, and which at best can be 

 only very approximate. Therefore, besides the primary purpose of 

 determining- the consumptive use of water by tules, it was desired to 

 demonstrate the impracticability of attempting- to determine their use 

 of water in swamps from experiments conducted with tules planted 

 in isolated tanks outside their natural environment. 



Tule Tank No. 1, 2 feet in diameter and 3 feet deep, was set in 

 the ground on the bank for the purpose of demonstrating the effect of 

 exposure on the use of water by plants grown in tanks. The rim of 

 this tank was set 1 inch above the surrounding ground surface. This 

 tank was filled with soil taken from the swamp. A sparse growth of 

 salt grass around Tank No. 1 did not reach higher than an inch at any 

 time during the season, so that the growth in the tank had a full 

 exposure. The evaporation pan was placed on the bank in the standard 

 manner and had good exposure, similar to that of Tank No. 1. 



Two tule tanks were placed in the swamp. Tank No. 2 being 2 feet 

 in diameter, and Tank No. 3, 6 feet in diameter. Both tanks are 3 feet 

 deep and set in the swamp 30 feet from the bank. Cradles for the 

 tanks were made of 2-inch redwood planks and supported on piling so 

 that the elevation of the rims of the tanks was approximately 4 inches 

 above the water surface of the surrounding swamp. Pipe lines wei-e 

 connected to the tanks 1 foot below the rim and extended to supply 

 tanks located in a sheltered dug-out in the bank. The tanks were filled 

 with swamp soil. 



A ground water well was sunk in the northeast corner of the plot 

 with a casing extending 30 inches below the ground water into a coarse 

 ^and. Records of the height of the ground water were kept at this 

 well, but the fluctuations were very slight. The water supply for the 

 various tanks was obtained from a cased well about 2 feet in diameter 

 and 3 feet deep, located near the edge of the swamp. 



