SECTION III 

 TILE DRAINAGE IN THE SAN JOAQUIN VALLEY 



Simply statedj a subsurface drainage system consists of a 

 deep open drain or some form of conduit so placed In the 

 soil that It effectively drains subsurface water away from 

 the root zone within a field. Subsurface drains and tile 

 drains are used Interchangeably in this report and refer to 

 tile, concrete, plastic, or other pipeline material used as 

 conduit . 



Several Interrelated factors influence the quantity and 

 quality of tile drainage from different parts of the Valley. 

 These factors are: (1) tile drain design, (2) materials 

 used in construction, (3) effective placement, (4) soil 

 characteristics, (5) agricultural management, (6) precipita- 

 tion, and (7) age of installation. These factors will be 

 discussed in the subsections that follow. 



Historic Background 



The first tile drainage systems in the San Joaquin Valley 

 were Installed at Kearney Park in Fresno County in 1905. 

 For many yesLrs thereafter, very few tile systems were 

 Installed elsewhere. The first tile drains along the west 

 side began to appear in the central area near the town of 

 Flrebaugh around 1950, following 20 years of successful 

 operation in the Imperial Valley. During the next decade, 

 many systems were installed, not only in the vicinity of 

 Flrebaugh but also in the northern and southern areas near 

 the towns of Tracy and Corcoran, respectively. During the 

 last decade more tile systems have been Installed nearly 

 every year near Flrebaugh and Tracy; the installation of 

 tile systems in other areas has been somewhat sporadic. 



T ile Drain Design 



Tile drain designs have changed very little from the first 

 known tile system (2) Installed near Geneva, New York, in 

 1835. Considerable work has recently been accomplished on 

 tile drainage theory by many Investigators (3)> but practical 

 application at this time has been thwarted by efforts to 

 deal economically with variable soil conditions (i.e., 

 stratigraphy, barrier depth and permeability) that exist in 

 west side soils. In some cases the proximity of canals and 

 local physiographic features such as rivers, sloughs, and 

 depressions may be Influential in determining the design 



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