Evaluation and Selection of Gate Type for a Tide Gate

Virginia Beach, like many coastal communities, is experiencing more frequent flooding due to sea level rise, increased storm intensity, and aging infrastructure. These issues coupled with tidal impacts and low elevations have resulted in severe flooding in portions of the City. As a result, the City embarked upon an extensive, multi-year flood mitigation improvement program. The program includes major infrastructure projects including three tide gates, two pump stations, and thousands of feet of flood barriers.  In addition, tens of thousands of feet of storm drain pipe improvements will be constructed.

The purpose of the Tide Gates is to preserve storage for runoff by preventing incoming tidal flows from filling the available capacity.

The City is about to start construction on the first of the major infrastructure projects: the Windsor Woods Tide Gate on Thalia Creek near Mount Trashmore Park.  Before the design team could begin the final design of the Tide Gate, the gate style and size of mechanical gate to be used had to be selected.  The gate style dictated the structural requirements of the Tide Gate superstructure.

The presentation will discuss the engineering evaluation performed to determine the most effective and economical gate style.  Investigated styles included: Swing Gates; Flap Gates; Slide Gates; Tainter Gates; Crest Gates; and Roller Gates.  Considered criteria included operation, size, operation, flow control, impacts of tidal flows, maintenance, and aesthetics.