While rice culture did not positively require inundation, it was facilitated by the periodical flooding of the fields, a practice which was introduced into the colony about 1724.  The best lands for this purpose were level bottoms with a readily controllable water supply adjacent.  During most of the colonial period the main recourse was to the inland swamps, which could be flooded only from reservoirs of impounded rain or brooks.  The frequent shortage of water in this regime made the flooding irregular and necessitated many hoeings of the crop.  Furthermore, the dearth of watersheds within reach of the great cypress swamps on the river borders hampered the use of these which were the most fertile lands in the colony.  Beginning about 1783 there was accordingly a general replacement of the reservoir system by the new one of tide-flowing.[4] For this method tracts were chosen on the flood-plains of streams whose water was fresh but whose height was controlled by the tide.  The land lying between the levels of high and low tide was cleared, banked along the river front and on the sides, elaborately ditched for drainage, and equipped with “trunks” or sluices piercing the front embankment.  On a frame above either end of each trunk a door was hung on a horizontal pivot and provided with a ratchet.  When the outer door was raised above the mouth of the trunk and the inner door was lowered, the water in the stream at high tide would sluice through and flood the field, whereas at low tide the water pressure from the land side would shut the door and keep the flood in.  But when the elevation of the doors was reversed the tide would be kept out and at low tide any water collected in the ditches from rain or seepage was automatically drained into the river.  Occasional cross embankments divided the fields for greater convenience of control.  The tide-flow system had its own limitations and handicaps.  Many of the available tracts were so narrow that the cost of embankment was very high in proportion to the area secured; and hurricanes from oceanward sometimes raised the streams until they over-topped the banks and broke them.  If these invading waters were briny the standing crop would be killed and the soil perhaps made useless for several years until fresh water had leached out the salt.  At many places, in fact, the water for the routine flowing of the crop had to be inspected and the time awaited when the stream was not brackish.

[Footnote 4:  David Ramsay, History of South Carolina (Charleston, 1809), II, 201-206.]

Economy of operation required cultivation in fairly large units.  Governor Glen wrote about 1760, “They reckon thirty slaves a proper number for a rice plantation, and to be tended by one overseer."[5] Upon the resort to tide-flowing the scale began to increase.  For example, Sir James Wright, governor of Georgia, had in 1771 eleven plantations on the Savannah, Ogeechee and Canoochee Rivers, employing from 33 to 72 slaves each, the great majority of whom were working hands.[6] At the middle of the nineteenth century the single plantation of Governor Aiken on Jehossee Island, South Carolina, of which more will be said in another chapter, had some seven hundred slaves of all ages.