Moriches Inlet Jetties
Great South Beach and Pikes Beach, New York
New York District
Construction and Rehabilitation History
Construction of two jetties by local interests was completed at
lengths of 750
east and 1,420
west. Elevations were
mlw, crown widths were 12.0 ft, and side slopes were
layer of capstone was placed over core stone, which rested on a
2-ft-thick blanket. Stone sizes used on the east jetty were 4.0- to
10.0-ton capstone and 5.0-lb to 1.0-ton core stone on the shoreward
580 ft, and 6.0- to 12-ton capstone and 5.0-lb to 2.0-ton core stone
on the remainder of the jetty. The west jetty consisted of 2.0- to
6.0-ton capstone and 10-lb to 1,000-lb core stone on the shoreward
1,280 ft and 6.0- to 12-ton capstone and 10-lb to 1.0-ton core stone
elsewhere. Blanket and apron stone was 5.0 to 500 lb and 1
500 lb on the east and west jetties, respectively. Cost was 7,630
for the east jetty and 0,210 for the west jetty, all non-Federal
Local interests extended the jetties to 8 1
east and 1,461 ft west
Core stone used was 1 lb to 5.0 ton, east jetty, and 1 lb to 2 0
tons west jetty. A 2.0-ft-thick blanket and apron was placed using
15- to 500-lb stone. Jetty ends were approximately 800 ft apart.
Cost was 4,290 east and 2,260 west.
An inspection of the jetties was conducted. Stone on the inlet side
of both jetties had slipped at numerous locations. Slope stones and
capstones had unraveled at the outer end of the east jetty. Approxi-
mately 300 ft of the west jetty had settled 2.0 to 3.0 ft. The
jetties had undergone severe wave attack since their construction,
and most of the damage was attributed to the hurricane of August
A survey indicated the jetties were in a good, stable condition. The
jetties had settled approximately 2.0
on the east jetty
ft on the west jetty. The jetties did not meet Corps of
Engineers standards for armor stone layer thickness, weight, or ele-
vation, and it was determined that it would be more economical to
maintain the jetties on an annual basis than by rehabilitation.
Potential damage was anticipated to increase.
No further repair or maintenance information has been found.