HEARNS POND DAM IMPROVEMENTS

OWNER: DelDOT/DNREC

ENGINEER:  McCormick Taylor

PROJECT TYPE: Rehabilitation of Existing Dam, Spillway, & Outlet Works and Preservation of a National Historic Landmark Building

LOCATION: Seaford, Sussex County, DE

DESCRIPTION OF PROJECT:

• Protection and preservation of a Nation Historic Building during close proximity construction activities including impact and vibratory driven piling

• Design and installation of a sheet pile cofferdam to allow demolition of existing spillway and bridge structure

• Maintaining a constant water elevation in the lake as required by environmental compliance

• Cast-in-Place concrete ogee spillway (~1200 CY of concrete) with all necessary waterstop details.The concrete ogee was considered mass concrete, so procedures and plans were necessary for DelDOT acceptance.

• Installation of 6” and 7.5” articulated concrete block (13,750 SF and 8,500 SF) overtopping protection on the crest and downstream slope of the embankment

• Precast post tensioned double barrel culvert

• Installation of permanent sheet piles along with impact driven friction piles

• Installation of new sluice gate and stop log system

• Installation of a new concrete cast-in-place boat ramp