New Dam at Wilkes-Barre.
The Spring Brook Water Supply company of Wilkes-Barre, Pa., has just completed its Deep Hollow reservoir which will add nearly a quarter of a billion gallons to the storage capacity, and will help to supply the Heights when the regular supply for that section runs low. The work on the dam was started ab6ut the middle of 1907 and was completed on July 6, 1908, the concrete work having been begun in August uf last year. The reservoir is located in the bed of Deep Hollow Run, about 1,800 feet up-stream from the point where the canal is situated that was constructed about two years ago to carry the surplus water front Mill creek into the Laurel run reservoir to augment the supply for that section. The greatest depth of the reservoir at the site of the dam is 43 ft.; at the lowest point of the tracks of the cut-off, which runs opposite it for some distance and limits its depth, the water will come to within 4 in. of the rail case. The reservoir, whose capacity is 241,500.000 gals., will cover 40.11 acres of ground. The dam is of concrete and is built on the solid rock, both the earth and loose rock on the surface having been scraped off to provide a firm foundation. The face of the dam is circular iti form, and the top length of the arch is 675 ft. In addition to these, there arc a wing-wall 117 ft. in length, a spillway wall 84 ft. long and a wall running parallel with the railway tracks, having a total length of 400 ft. This wall is also set on solid rock base and is designed, not only to protect the tracks, but to prevent their seepage from escaping into the reservoir. The total length of all the walls built is 1,276 ft. The top of the dam is 2 ft. above the water-surface, and at this point is 4 ft. in thickness. The greatest height of the concrete wall is 47 ft., and from the surface of the water to the base of the dam the wall increases in thickness 7 in. to the foot, so that at the base of the dam the wall has a thickness of over 30 ft. The dam will get the surplus flow of the Deep Hollow run or creek, and will store it, this having heretofore been allowed to go to waste, although the regular flow of the run will be caught by tbe Mill Creek-Laurel run canal. The overflow from the dam will fall into the old bed of the creek, which has been concreted at the base of the dam, and that which escapes bv wav of t*-«spilway will eventually reach the old creek bed. The entire cost of this improvement to the system was nearly $75,000. In building this dam 42 acres of ground were cleared, and it was necessary to make a road about 2,000 ft. in length and excavate 2,200 cu. yds. of earth and i,?oo cu. yds. of rock. In the construction of the dam it,000 cu. yds. of concrete were used, formed of 12,000 barrels of Atlas cement, about 6,000 cu. yds. of sand from a nearby pit and stone from a crusher set up close to the site of the dam.