Taken on a dike that separates the Ashley River from old rice fields. The ‘trunk’ that regulates the water flow has been here in some form since the late 1600’s when the plantations were first built.
The design hasn’t changed all that much. The river is tidal so it has some salt, the wooden trunk is pushed in and out, just on the waters surface. Fresh water is lighter than salt so the top layer of water feeds into the rice field, salt is left behind. The design originated in West Africa and brought over with people when enslaved.
Rice doesn’t like salt water. Neither do Alligators. Above was taken on the rice field side of the dike, and the trunk. Water moves through a wooden box buried in the dirt that makes up the dike. Tide moves the water back and forth.
Big fields like this may have trunks every mile or so.