You’ve probably never seen anything like this, but I can assure you that this photograph is one of the most iconic photographs of all when it comes to the Lowcountry. Before the era of electrically powered water pumps, water had to be brought to the rice fields using the earth’s power.
That’s where the floodgate comes into play, and without it, the production of rice would have been impossible.
The South Carolina Lowcountry was perfect for growing rice because the state has five great rivers that are all subject to the tide. Twice a day the tide comes in and forces the rivers to back up in their beds. Twice a day, the tide goes out and releases the fresh river water into the sea.
Rice requires periodic flooding, in addition to three major ones per season. The flooding were achieved by raising the floodgate, which is called a TRUNK in the Lowcountry, at high tide to allow the river water into the field. Emptying the fields was done by opening the trunks at low tide, to allow the freshwater out of the fields on its rush to the sea.
Rice will die when exposed to seawater—the slightest amount of salt will kill rice, so the plantations had to be built at points along the river where the fresh water could flood their fields upon opening the trunks, but not too close to the sea, so that even during an usually high tide, saltwater could not touch the rice fields.
Being able to read the river and the tides, took a great deal of skill. One of the most important and prestigious jobs on a plantation was that of TRUNK MINDER. Why did they call floodgates trunks? Because in Africa, floodgates were made out of tree trunks.