Designation(s) SHAFT NUMBER 25 STEPS AND RETAINING WALL c 1892 Plate 29, New Croton Aqueduct Type Marking the point where the New Croton Aqueduct entered Manhattan Island, Shaft Number 25 employed revolutionary engineering in its design. Significance(s) Interpretation An elaborate stairway was built into the side of Shaft Number 25 with access to the Harlem River Speedway through a glorious arch. Current Designation(s) Type Significance(s) Significance(s) Interpretation Sign Current Designation(s) SHAFT NUMBER 26 Plate 29, New Croton Aqueduct Engineered at a depth of 120 feet, Shaft Number 26 was also designed to protect Manhattan from any undue pressure resulting from the Harlem River Siphon. Type Significance(s) Current Designation(s) Interpretation Sign SHAFT NUMBER 29 Plate 30-3, New Croton Aqueduct Type Significance(s) Interpretation Sign Type Sign Current Designation(s) At Shaft Number 30, engineers planned on sinking the shaft to a depth of 81 feet. Soft clay and decomposed rock was encountered, however, causing a cave-in and loss of life. SHAFT NUMBER 27 Plate 29, New Croton Aqueduct Shaft Number 27 was sunk to 144 feet. Type Significance(s) Interpretation SHAFT NUMBER 30 Plate 30-15, New Croton Aqueduct Current Designation(s) Type Significance(s) Structure Guide A brick vault with two manhole covers served as a headhouse for Shaft Number 26. Critical to the equalizing of the pressure from the Harlem River Siphon, it served as an overflow dam. Shaft Number 29 was designed to a depth of 114 feet. Interpretation Appendix SHAFT NUMBER 26 HEADHOUSE (Demolished) Plate 29, New Croton Aqueduct Significance(s) Interpretation Sign Sign Current Designation(s) Current Designation(s) SHAFT NUMBER 31 Plate 30-14, New Croton Aqueduct SHAFT NUMBER 28 Plate 31-1, New Croton Aqueduct At Shaft Number 28, engineers predicted a necessary depth of 128 feet. On 141st Street, engineers expected Shaft Number 31 to sink to a depth of 82 feet. Type Type Significance(s) Interpretation Significance(s) Interpretation Sign Sign Current Designation(s) Current Designation(s) 39 SHAFT NUMBER 32 Plate 30-12, New Croton Aqueduct SODOM AUXILIARY DAM 1888-1892 Plate 5-, New Croton Aqueduct Engineers expected the Shaft Number 32 to reach a depth of 87 feet. Running parallel to the Croton River, the earthen Sodom Auxiliary Dam is nearly 600 feet long and 75 feet high. Type Significance(s) Interpretation Sign Type Significance(s) Interpretation Sign Current Designation(s) Current Designation(s) SING SING BRIDGE c 1840 Plate 22-2, Old Croton Aqueduct Spanning 20 feet the Sing Sing Bridge arches over a street in the village of Sing Sing. Type Significance(s) Interpretation Sign Current Designation(s) Type Constructed across a valley where a stream had worn a deep channel, the Sing Sing Kill has an elegant arch spanning 88 feet. For more information, see fiche on page XXX. Significance(s) Current Designation(s) 40 Faced with blue-gray limestone, the solid masonry dam rises to a 75 foot height. The battered stone portion is flanked by earthen walls with a masonry core that when combined stretch 500 feet along the East Branch of the Croton River. For more information, see fiche on page XXX. SING SING KILL BRIDGE 1842 Plate 20-8, Old Croton Aqueduct Type SODOM DAM 1888-1892 Plate 5-, New Croton Aqueduct Interpretation Sign Significance(s) Current Designation(s) Interpretation Sign SODOM RESERVOIR 1888-1892 Plate 5-, New Croton Aqueduct Vertical jets sprout from a 80 foot diameter fountain that aerates water from the Sodom Reservoir. Comprising two dams and an overflow weir, the Sodom Reservoir, a part of the East Branch Reservoir, is capable of impounding nearly 5 billion gallons of water. Significance(s) Interpretation Sign For more information, see fiche on page XXX. Type Significance(s) Interpretation Sign Current Designation(s) SODOM DAM GATEHOUSE 1888-1892 Plate 5-, New Croton Aqueduct Current Designation(s) A 37 X 42 foot stone gatehouse near the center of the Sodom Dam regulates the water in the Sodom Reservoir at three elevations. Type Significance(s) Interpretation Structure Guide Type Appendix SODOM DAM FOUNTAIN 1888-1892 Plate 5-, New Croton Aqueduct Sign SOUTH GATEHOUSE 1862 Plate 32-7, Old Croton Aqueduct With a substructure at 83 X 40 feet, the South Gatehouse at Lake Manahatta in Central Park was composed of a sturdy granite exterior with a small balcony overlooking the reservoir. For more information, see fiche on page XXX. Current Designation(s) Type Significance(s) Interpretation Sign SODOM OVERFLOW WEIR 1888-1892 Plate 5-, New Croton Aqueduct A continuation of the Sodom Auxiliary Dam, the overflow weir stretches 500 feet and is 8 feet high. Type Significance(s) Interpretation Current Designation(s) Sign Current Designation(s) 41 SOUTH YONKERS GATEHOUSE c 1888 Plate 28-XX, New Croton Aqueduct Type A masonry substructure with a 37 X 55 foot chamber divided by an overflow weir, the South Yonkers Gatehouse is similar in form to the two other gatehouses placed between Croton Lake and the Harlem River. Here, Tibbit’s Brook, into which the waste water is discharged, passes under the gatehouse through two circular culverts. Type Significance(s) Interpretation Sign Current Designation(s) Interpretation Sign Current