Patent ID: 7435036

Claim:
A flexible water gate for retaining water in a port, a canal or a river estuary comprising a unitary flexible membrane having a first surface, a second surface, a first side and a second side; a gate operating mechanism that moves the flexible membrane between a closed position and an open position, wherein the flexible membrane is lowered from the closed position to the open position, wherein in the open position the flexible membrane is stored on the bed of the port, canal or river estuary to provide unrestricted access to said port, canal or river estuary; a first recess located at the first side and a second recess located at the second side of the flexible membrane; and a first side seal and a second side seal associated with the first recess and the second recess, respectively, wherein the first and second side seals are located on the low water side of the flexible membrane such that when the flexible membrane is in the closed position a hydraulic pressure associated with a retained water acts against the first surface of the flexible membrane to maintain the second surface of the flexible membrane against the first and second side seals forming a watertight seal along each of the first and second sides of the flexible water gate; wherein the gate operating mechanism comprises a mechanical pulley system and a plurality of adjustment means and a plurality of support lines, wherein the plurality of adjustment means connect the plurality of support lines to the mechanical pulley system.