Lake Falmouth Dam Repairs – Clemmons

The Runnymede Acres Homeowners Association in Clemmons, North Carolina maintains the common area within their subdivision which includes Lake Falmouth. The project included upgrading the spillway capacity to meet High Hazard requirements and replacing a failed principal spillway with a new system. The Lake Falmouth Dam was the main entrance into the subdivision and also a NCDOT roadway.  The site had a limited area for additional spillway construction and the project also required NCDOT approval since the dam formed a public roadway.

In order to prevent total removal of the dam, a siphon system was installed to act as the primary spillway.  A weir wall was constructed as a secondary spillway, which allowed the small storms to be stored in the reservoir and allowed the existing roadway culverts to flow efficiently during large storm events.

Design of the project included surveying, easement acquisition, HEC1 Modeling to confirm spillway capacity, site grading, spillway improvements, Land Quality permits for dam repairs and erosion control, and NCDOT encroachments for dam/roadway construction.  The repairs included installation of approximately 200 LF of 12″ Ductile Iron Class 50 Siphon with sluice gate, valves and 6″ Ductile Iron siphon break with trash guard and toe drain, approximately 50 LF of 12″ Concrete Block weir wall, and pressure grouting of existing corrugated metal riser and barrel.

Project Manager:    G. Wesley Webb, P.E.
Completion:        1995
Construction Cost:    $40,000