[Footnote 3: McCrady, _South Carolina under the Royal Government_ (New
York, 1899), pp. 389, 390, 807.]

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 régime 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