Abstract: The impact of a proposed pier on tidal current
alteration was evaluated. The proposed pier location was in Salad
Bay on Koa Kood Island, Trat province, Thailand, and was designed
to accommodate passenger ships with a draft of less than 2 m. The
study began with collecting necessary data, including bathymetric,
water elevation and tidal current characteristics. The impact was
assessed using a software package (MIKE21). Although the results
showed that the pier would affect the existing current pattern, the
change was determined to be insignificant, as the design of the piles
for the pier provided sufficient spacing to let the current flow as
freely as possible. Consequences of the altered current, such as
seabed erosion, water stagnation, sediment deposition and
navigational risk were assessed. Environmental mitigation measures
might be necessary if the impacts were considered unacceptable.