Water Motions in Closed-End Residential Canal

Waterfront housing on closed-end canals is a frequently encountered mode of shoreline development in Florida and other States. Indications are that many of these canals at one time or another have substandard water quality as characterized by low dissolved oxygen and plankton blooms. In general these substandard conditions are associated with weak circulation and insufficient exchange with the parent body of water. In engineering evaluations it has been common practice to attribute the circulation and exchange in residential canals to tidal currents and tide-induced mixing. The objective of the present study is to test this hypothesis or more generally to delineate the various water motions in closed-end canals and to determine their relative importance with regard to circulation and exchange with the parent body of water. To this extent measurements were carried out in Martinique Waterway, a straight closed-end canal on Marco Island, FL. Even Though the study was of an exploratory nature, publication of the results seems justified at this time in view of, on the one hand, the large interest in the design and improvement of canals and, on the other hand, the limited amount of available scientific data.