|Until I was fifteen, the only kind of dyke I knew of was the sort that the Acadians built - the long, narrow, flexible, winding, practical dikes that slip past Digby Neck and down into the Minas Basin, that keep the salty waters of the Atlantic quite literally, at Bay. Dikes line the banks of the Annapolis River and the Avon and the Gaspereau Rivers and they buffer the fertile land of Grand Pré from whence their technology originated and they keep Greenwich and Port Williams perpetually apart.|
Permeable Dikes, instead of entirely cutting off or diverting the current flow, merely slacken and retard it. They consist of open work construction, usually of timber piles and cribbing with rubble weighted brushwood mattress work hurdles. The velocity of the current being retarded behind or between such dikes, material in suspension is deposited and the area is filled up until the dikes themselves eventually become buried in a hydraulic fill of their own creation. On account of the initial increase in velocity at the contracted area of the dike itself, the mattress work is built with an apron on each side of the work to prevent scouring and undermining.