TIIK \V^]\ in'X'T.AMATTON PROJECT. 887 



several feet helow the lowe^l point of tlie stream bed. This striicltire 

 will he of steel and i-oiierete. some ;>.()()() feet in leniith. It Avill he an 

 inverted syphon consist inf>- of four concrete pipes 10 feet in diameter 

 reinforced with steel rods. 



Because of the annual rise of the Colorado River, a large portion 

 of the lands along this stream are suhject to annual overfloAv, which 

 practically prevents residence thereon, as well as the farming of 

 I hem. without jjrotective works. The levee, therefore, is considered 

 an essential feature of the enterpi'ise. The shape of levee adopted 

 is one that has been developed hy years of experience along the 

 J\lississii)[)i Iviver. It will have a slope of 3 feet horizontal to 1 

 foot vertical on the water side, and 2^ feet horizontal to 1 foot vertical 

 on the land side; it will be 8 feet wide on top, and be l)uilt 5 feet 

 above the highest water marks of the year 1903. These levees will 

 be 4,000 feet apart (one on each side) along the Colorado River, 

 and O.-200 feet ai)art along the (iila River. 



Because these lands are so flat, and the level of the water in the 

 ground so near the surface, it is considered necessary, for their 

 permanent safe irrigation, to supply a drainage system. A main 

 drainage canal has been designed to run through the central portion 

 of the areas to be irrigated, and when possible the natural drainage 

 lines of the country will be utilized, deepening them with a steam 

 dredger to such depth that they will carry oil' the water returning 

 from irrigation or seeping through the levees during the high-water 

 stage of the river. 



When lands in any district tend to become alkaline they may 

 be connected, by means of local drainage canals, with this main 

 drain, and in this manner they could be kept free from alkali by 

 holding down the level of the ground water. During the greater 

 portion of the year, when the river is low, this drainage water 

 would be discharged into the stream, but when the river is in flood 

 its elevation will be such as to prevent a discharge into it from the 

 drains. A pumping plant has therefore been designed to lift the 

 drainage waters o\ev the levees during the flood period of the river 

 to prevent the lands becoming water-logged. 



The whole system, as planned above, is one looking to the per- 

 niancMit reclamation of this district by means of irrigation, levee, 

 and drainage works. All portions of the system to be made of steel, 

 conci'ete, or earthwork. 



The reports of the Department of Agriculture on the character 

 of the soils of this valley, as Avell as past farming experience, indi- 

 cate that they ai'e exceedingly fertile. The silt of the Colorado 

 River, all of which can not be removed at the headworks, has high 

 fertilizing properties. Undei' these conditions, and with proper 

 handling of the system, the \alley should be perpetually fertile. 



