In
my report on the proposed Reservoir Istate,
"Perhaps the most important portion of this work is
the means for safely passing
off flood waters. The average
annual rainfall during
the last seven years,
1860 excepted, will be found
from the accompanying
statement to be 81 inches.
The Gathering
Ground is 550 acres.
The Reservoir area will
probably be about ... acres.
I propose to construct the Bye Wash as shown on
the Plan 80 ft x 5ft and calculate that it will
discharge 11,016,000 cubic feet of
water per hour or a rain
fall on the Gathering Ground of nearly 2 in. per hour.
It
would appear to be
impossible that such a
rainfall could ever
fall, there has
however been a depth of
2.6" of water over the existing
weir which is 120 feet wide
and I simply give a waterway
of 400 square feet in
place of 300 square feet
which has actually been
found to be required.
A Culvert under the Bye
Wash is provided for use
in case of emergency
with the Sluice Valves in the
Valve Well will discharge
a further 2,091,600 cubic feet per hour."
Mr Rawlinson has stated in his Report of 7th November last that the dimensions
of the Bye Wash are ample