810 



WATER WOKKS. 



1,029,000,000 K Y. galls. It has been built 

 on the most substantial plan and in the most 

 careful and skilful manner possible. The pud- 

 dle trench is carried down to and founded on 

 the solid rock throughout its entire circuit. 

 The interior slopes are protected by a facing 

 of hydraulic masonry. 



There are three gate houses. The first of 

 these gate houses is that by means of which 

 the water is taken out of the old aqueduct, at 

 the corner of 9th av. and 92nd st. The old 

 aqueduct has been opened for the space of 46 

 feet, and a chamber built, combining two sets 

 of gates one set permitting the water to pur- 

 sue its old course through the old aqueduct to 

 the present receiving reservoir at 85th st., and 

 the other set diverting the water into the new 

 junction aqueduct, which leads to the new 

 reservoir. There are 5 gates to each chan- 

 nel, so arranged that all the water can be 

 passed either into the old or new reservoir 

 at pleasure, or a portion sent to each. From 

 this junction gate house to the north gate 

 house of the new reservoir, the aqueduct is 

 2,629 feet in length, and similar, in the form 

 of its sectional area, to the old aqueduct. In 

 order to carry this structure across the 9th 

 av. and through 92nd st., without interfering 

 witli their grades, it was necessary to place 

 it about 7 ft. below the regular level of 

 the old aqueduct. When, therefore, the old 

 aqueduct runs full, there will be a pressure on 

 the top of the new one, due to that height. 

 The masonry has been accordingly strengthen- 

 ed to meet this pressure. 



The junction aqueduct terminates at the 

 north gate house of the reservoir. This gate 

 house, situated at the north end of the central 

 or dividing bank of the reservoir, serves the 

 double purpose of an inlet and an outlet gate 

 house. The water is received into an induc- 

 tion chamber, wliich is furnished with 2 sets 

 of gates, 5 in each set. Through these gates 

 the water is discharged immediately into either 

 or both of the divisions of the reservoir, at 

 pleasure. Directly below the induction cham- 

 ber are the inlet channels from the 2 divisions 

 of the reservoir to the fore bays, which are 

 the entrances to that portion of the gate 

 house which is arranged for the discharge of 

 the water into the city. These fore bays are 

 divided into spaces 7 ft. in width by 12 ft. in 

 length. The fore bays are built of granite. 

 In front of the gates which let the water into 

 the main outlet chambers, grooves are cut in 

 the sides of the fore bays for a double set of 

 screens of copper wire gauze, and for the in- 

 sertion of temporary coffer dams, should they 

 ever be required. Beyond the gates is the 

 t)ack bay, into which water passes from both 

 divisions of the reservoir. This back bay is 

 so arranged, however, that the whole of it can 

 be filled with water from either division at 

 pleasure. And, again, it can be divided in 

 itself, so as to use but one portion of it at a 

 time, should it be necessary. The rear wall 



of the back bay separates that portion of the 

 gate houses into which the water flows from 

 the portion of it called the pipe vault. In this 

 wall are inserted the mouths of the outlet 

 pipes. In the pipe vault beyond, and through 

 which the pipes pass into the city, are the stop 

 cocks controlling the pipes and other arrange- 

 ments for division and shutting off water, 

 should repairs to the stop cocks or pipes be re- 

 quired. The vault is entered from the top of 

 the bank by a circular staircase, through a 

 well large enough to admit the lowering of 

 pipe, or stop cocks, or other material. Un- 

 derneath the whole of this structure passes 

 the main sewer, to receive the overfall of 

 water from the waste weir, which is also in- 

 cluded in the general plan of the gate houses. 



Passing under the floor of the gate house, 

 there is also a pipe, 3 ft. in diameter, leading 

 from each division of the reservoir to the main 

 sewer, at a point beyond the pipe vault. These 

 pipes are not in any wise connected with the 

 distribution pipes, but are intended only to 

 draw off the water from either division, when 

 necessary. 4 distribution pipes lead from this 

 gate house to the upper part of the city, each 

 3 feet in diameter. 



The south gate house is situated at the south 

 end of the bank dividing the reservoir. It is 

 arranged only for distribution, and has, there- 

 fore, no induction chamber for the purpose of 

 delivering water into the reservoir. In all 

 other respects it is similar in design and char- 

 acter of work to the north gate house, except 

 that if has 6, instead of 4, outlet or distribution 

 pipes, each of which is 4 ft. in diameter. 



Both gate houses are built on the natural 

 solid rock. The outer exposed walls and the 

 sides of the fore bays, the openings for the 

 gateways, screens, &c., the wells for the waste 

 weirs and their approaches, the mouth pieces 

 to the pipes, and the braces in the fore bays, 

 are of granite. The walls under the banks are 

 of gneiss and brick, the other face walls and 

 arches are of brick, while the foundations and 

 the interior of the walls are of concrete. The 

 tops of all the walls of the gate houses are 

 covered with a floor of granite 1 ft. in thick- 

 ness. On this floor will be placed the gearing 

 for working the gates below, a vertical distance 

 of 44 ft. The gates and gate frames are of 

 cast iron, with the sliding parts faced with 

 brass. There are upper and lower sets of 

 gates, by which a circulation in the water can 

 be effected, and which at the same time will 

 facilitate other operations. With a view to 

 provide for every possible contingency, there 

 is no portion of the whole work which cannot 

 be examined and repaired without shutting off 

 the water from the city for a moment. 



There are now 5 main pipes supplying the 

 city from the old receiving reservoir, as fol- 

 lows : 1, 2=5 ft. in diam., from the west side of 

 the reservoir, passing down 8th av. ; 1, 2^ ft, 

 in diam., from the east side, passing down 3d 

 av ; 2, each 3 ft. in diam., passing down the 5th 



