CHAPTER II 



INVESTIGATIONS IN THE SANTA ANA RIVER VALLEY 



AND COASTAL PLAIN 



By A. A. Young * 



This chapter deals ^vHh. the consumptive use of water in the Santa 

 Ana River basin by varions types of moist area native vegetation 

 commonly found along stream beds, swamps and cienagas, and the 

 evaporation from moist soil without vegetative growth. 



As originally outlined the plan of the investigation was to deter- 

 mine by tank experiments the use of water by wild grasses, and evapo- 

 ration from bare soil in moist areas. Two experiment stations were 

 established, one at Santa Ana and one at San Bernardino in 1929, and 

 a third, at Prado, was added in the following year. In the vicinity of 

 each are certain areas with relatively high ground water supporting 

 moist area native growth from which samples were selected for trans- 

 planting into tanks for study. 



A progress report giving results of studies at Santa Ana and San 

 Bernardino stations of consumptive use of water by salt grass and 

 Bermuda grass, and evaporation from uncultivated bare soil for the 

 year ending May 1, 1930, has been published.** Since that bulletin 

 was M-ritten several changes and additions have been made to the 

 original set-up and the experiments have been extended to include 

 the measurement of consumptive use of water by round stem tules and 

 triangular stem tules, cat-tails, wire rush and willows grown in tanks. 

 These studies were continued for an additional two years following the 

 published progress report in 1930, and the data assembled during that 

 period are presented herewith as a final report! of the investigations 

 made. 



SANTA ANA STATION 

 Description of Site 



Following a survey of western Orange County early in 1929, in 

 which a study was made of soil type and soil moisture conditions, a 

 small plot of ground was selected as the site for the Santa Ana experi- 

 ment station for studies of consumptive use of water by moist area 

 vegetation. The plot is in a level 10-aere field of small native vegeta- 

 tion, 4 miles west of Santa Ana and about 7 miles inland from the coast. 

 It is free from windbreaks and shade and is generally suitable in 

 regard to soil, climatic conditions, and exposure to the elements for 

 the studies undertaken. The station ground is 50 by 100 feet and is 

 surrounded bj' a tight woven Avire fence for protection. Plate I is a 

 general plan of the station showing the arrangement and uses of the 

 various tanks. 



* Assistant Irrigation Engineer, Division of Irrigation, Bureau of Agricultural 

 Engineering, U. S. Department of AgricuUure. 



** Part II. Bulletin No. 33, Rainfall Penetration and Consumptive Use of 

 Water in the Santa Ana River Valley and Coastal Plain. 1930. State of California, 

 Department of Public "Works, Division of Water Resources. 



t Credit is due to Dean C. Muckel, Junior Civil Engineer, Bureau of Agricultural 

 Engineering, for valuable assistance in collection of data from October, 1930, to 

 December, 1.931, and in preparation of the report. 



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