Arizona republican., 1906-03-16

Around each end of the dam will be cut tne "spillways" or oyernows to conduct floods or surplus water from the reservoir over a solid rock channel slOping down to the river. These spillways will be twenty y-fve feet low CT than the crest of the dam and will each be 200 feet wide. They are cal culated to accommodate as great a flood as has ever been recorded in the river, without permitting the water-to flow over the crest of the dam. over each spillway will be thrown a re- inforced concrete bridge. level with the top of the dam and forming with it a roadway across the canyon con meeting with high line roads at each end.
 Rock blasted out of the spillways will be used to build the dam, and the clearing up of these utility quar- ries is now going on with large force of men. The Republican told in it's columns last week of one blast of half ton of powder which was set off by electricity to clear the face of the mountain Of tons of rock and rubbish which went sliding into the river be- low. The rock to be used for build ing purposes IS of hard red sandstone. comparatively easy to work but of
 
 While excavating Tor the foundation of the dam is going on, the. water of the river is diverted in three ways. First is the power canal, eighteen miles in length. This big ditch. capable of carrying 10000 inches of water, or the normal flow Of the river at that point. takes water from Salt river by means of a small diversion dam and carries it along the rim of the reser- voir with gentle fall until the main dam site is reached. There the water is dropped through q pressure pipe about 600 feet long and with vertical fall of 226 feet. In order to stand the enormous force of the water as it goes roaring down to the huge turbine wheels below, this pipe is built of steel plates which were first set up within a shaft cut through the solid rock of the canyon wall and then the space between steel and rock was sOlidly filled with concrete. And the pipe is big enough for a man to walk through without stopping.
 A second means of diversion is by the big outlet tunnel, 10X13 feet, through which will be let out the stored water when the reservoir is completed. This tunnel is 800 feet long and curves around through the
 
 where one end of the big dam will be built into the rock. It will be estCpped by big steel. gates, set in a series of three for convenience of op- eration and repairs and which may be raised and lowered through a shaft opening on the side of the canyon above The third means of protecting the excavation and foundation will be by means of a wooden Hume to be carried over the work as it progresses. Timber for this Hume as well as for other parts of the construction work has been cut in the forests of the Sierra Ancha mountains twenty miles above the dam site by means of a saw mill set up for the purpose, and 10 the extent of two million feet.
 The electrical power plant to utli- ize the water fall, through the pressure pipe into turbine wheels is set on shelf of rock just below the dam and to it lead the draug.lt tube and tail race. Five thousand constant horse power is generated when the power canal is operated to it's full capacity Some of the upper reaches of this canal called for construction of a pc culiar nature. Tributary creeks had to be crossed and to insure the stabil- ity and permanence of the canal the engineers decided not to carry 1t over tEcse ravines on sti,ts but to dip down under the bed of the stream in siphon tube construction. These tubes are built in duplicate and to make them a special alligator" machine or