Sediment Nourishment at Orchard Beach, the Bronx, New York

Abstract

Orchard Beach is a man-made, self contained sandy pocket completely dissimilar to the natural formation of the shoreline on which it is situated. The beach was created by connecting two rocky headlands with 4,000 feet of rock-filled crib seawall and concrete promenade, and backfilled with 1.2 million cubic yards of sand. Original construction was done between 1935 and 1937 by the City of New York, under the direction of Robert Moses. The beach was expanded 1,000 ft and two new rock terminal groins were added in 1949. Beach nourishments were performed in 1949 and 1964. The crescent shape beach is relatively stable due to low wave and current action; however, severe storms can overtop the berm and the crest of the promenade. For nearly 50 years since the last nourishment, the beach retained its integrity; however, by the early 2000’s the shoreline had shifted from north to south, resulting in a narrower and milder beach to the north and a wider and steeper beach to the south. In addition, formation of a large scour area with an abrupt drop-off slope presented a safety concern to swimmers. The beach is in the populated New York City metropolitan area and is frequented by 2.5 million visitors annually. During the summer season, the beach was overcrowded. Due to the gradual loss of sand to the north and a large 7 to 9 ft tidal range, beachgoers had little beach space during high tide and needed to wade out a long distance to reach the water during low tide. In 2009, USACE prepared the final construction plan for a beach nourishment and upgrade of the southern rock groin, and reached financial agreement with the New York City Parks & Recreation Department. The project was successfully bid by Great Lakes Dredge and Dock Co. (GLDD). Construction commenced on 30 th October 2010 and was completed on 28 th January, 2011.