Montauk Point Lighthouse Rehabilitation

The work consists of rehabilitation of an existing stone revetment/seawall surrounding the Montauk Point Lighthouse, Suffolk County, New York.  The revetment will be rehabilitated to protect the lighthouse and associated cultural resources situated on top of the bluff from damage due to erosion and wave impact from ocean waves and storm surge.  Top of the existing bluff elevation is approximately 65 ft above NAVD88.  The proposed approximately 1,000 linear feet stone revetment work consists of remove, reuse the existing 5-10 ton armor stone, placement of used and new 10 ton and 15ton median size armor, and provide slope stabilization with terracing and vegetation above the upper crest of the revetment.  The rehabilitated cross-section will slope up from the toe at a 2.5H:1V slope until el. +10 ft NAVD88, at which point there will be an approximately 20-ft wide horizontal lower rock bench.  From there, the revetment continues upward at a 2H:1V slope until reaching elevation +21 ft NAVD88.  The upper rock bench at +21 ft NAVD88 will be approximately 20-ft wide.  A stone splash apron from +21 ft to +35 ft NAVD88 constructed with new and reused 1-3 ton stone underlain by a geotextile mat completes the typical cross-section.  Planting and terracing with vegetation will stabilize the slope above the splash apron.  The work includes removal and re-arrangement of existing stone as needed to construct the rehabilitated cross-section.  Additional new underlayer sized stone will be placed as needed to allow for placement of armor stone.  The toe of the revetment will be keyed into existing rock bottom.  There are significant amounts of large and medium size rock from earlier revetments presenting at the toe of the structure.  Construction access can be from the beach north and south of the existing revetment.  It is anticipated that the lower bench will provide access for construction of the upper and lower portions of the cross-section.  New rock quantities are anticipated to be between 50,000 and 70,000 tons.