pg 017: The Austin dam Publication 2564523

information can be obtained might give a depth of water of 15 or 16 feet over the crest for a short time. Such a possible flow will be provided for in the construction of the dam. The exact lines of the profile and the detail method of construction are now being determined in consultation with Mr. Frizell.

During the summer of 1890 engineers were put in the field to locate the lake-level contours and to determine the amount of valuable land submerged. These engineers took cross sections of the river at sixteen stations, thus enabling comparisons to be made, which was done by the writer in May, 1897, and in January, 1900. The accuracy of the work under the supervision of Mr. Pope was verified by the fact that at the head of the lake, at the request of a farmer living near, he cut a bench mark, on a big pecan tree, at the crest level. Three years later the water, when it rose to the crest of the dam, reached the notch with exactness. Cross sections of the lake are shown in fig. 6; a general map of the lake is shown in fig. 2.

CONSTRUCTION OF DAM.

On October 15, 1890, the contract for the construction of the dam was awarded to the lowest of seven bidders, Mr. Bernard Corrigan, of Kansas City, Missouri, whose figures were $501,150. The contract was based upon the following specifications:

ROCK EXCAVATION.
12. On the site of the dam all unsound rock and all rock that can be removed without blasting will be taken off. A trench 4 feet wide and as deep as may be directed by the engineer will be excavated along the upstream face of the dam. Trenches, footings, steps, channels, and other excavations will be cut in the bottom and sides of the rock in such forms and to such lines as may be directed by the engineer. In these excavations the kind of explosive used, the amount of the charges, depth and direction of the holes, and the entire process of the work shall be under the immediate personal control of the engineer or his assistant, the object being to do the work in such a manner as to avoid fissures and shakes in the remaining rock. All cracks and fissures that may exist naturally or from any cause shall be thoroughly filled with cement mortar or concrete or pure cement, as may in each case be directed by the engineer.
13. The lines and grades of the canal will be established by the engineer, and no excavation below the grade or bottom or outside the lines will be paid for; but such excavation will be permitted, under the direction of the engineer, for the purpose of obtaining rock for the dam.
14. Any rock obtained from these excavations that the engineer may deem suitable may be used in the rubble masonry of the darn. Rock not suited for this purpose will be disposed of as the engineer may direct-in spoil bank, riprap, filling of cribs, or otherwise--not involving a haul of more than 500 yards. The price of rock excavation will include and cover the cost of all the explosives, tools, derricks, tackle, machinery, teams, vehicles, tramways, stringers, bridges, boats and appliances, materials, and labor used in the excavation of the work. All rock will be measured in excavation.
MASONRY.
15. The upstream face of the dam will be laid of granite. It must be sound, "
The original specifications called for fossiliferous limestone for the upstream face, but bids were also received for granite, which material was adopted. The details here given are obviously not proper for granite.