A view of the gates from outside the tidal basin. Along with the automatic, inlet and outlet tidal gates, there are also heavier duty curtain gates that could be rolled up and down when needed. These “curtain gates” were designed to be mechanically raised and lowered with the help of heavy iron counter-weights. Though the curtain gates are no longer operational, the DC Drift team regularly inspects and performs maintenance on the inlet and outlet gates. (USACE photos by Christopher Fincham)