This is a sociological brain teaser.
Before the advent of individual pit latrines on the sugar estates, where did sugar workers and their families lawfully relieve themselves?
In the TV show Who Wants to be a Millionaire? you can call a friend for an answer.
For the tickler above, feel free to call your grandfather, grandmother, great aunt, etc.
Over the trench or canals.
Correct. I remember the communal ones at Uitvlugt Estate in the 1950s. Separate ones for males and females.
This is what the Journal of the Board of Agriculture said in 1921:
"On sugar estates the system of sewage disposal is to place latrines over the open drainage trenches. Where a large volume of water is available and the trench is flushed out daily directly into the sea, this system is fairly satisfactory, but in cases where the trenches are small, shallow and inadequately flushed it leaves much to be desired especially as regards the spread of Ankylostomiasis and intestinal diseases generally."