4213
bouliers
sound
the
which Mr Foughtries predecessor, who built the house, had thrown upon top of the drain the heavy stone
of
which the embankment is partly composed. Another cause
of injury would be the great weight the drain was called upon to sustain by the action of Mr Foughtries predecessor
in the embankment and
house which he built on
the top of
the drain without duly strengthening
the latter.
13.
As to Colonel Shark's opinion that the damage to the drain would easily be accounted for by a gorging it with more water than it could discharge, I should point out that the larger drain collects the water from the area of 1.72 acres, shown tinted pink on the general plan, and the old Belmont drain collects the water from an area of 1.61 acres, tinted blue, making a total area of 3.33 acres.
From this minuter survey, I find therefore that I was too liberal in my previous calculations when I took the area of drainage to be 4.47 acres. The 13 inches of rainfall on 3.33 acres is only 524 cubic feet.
The drain, 20" x 18" at its narrowest point, with a fall of 1.4 in 20 feet at its most level portion, is capable, by formula, of delivering a greater quantity of water and sand to the latter than it will carry off the water from 3.33 acres, however hard it may rain; it is perfectly clear...