New Orleans Republican. [volume] (New Orleans, La) 1867-1878, 1871-06-21
ORLEANS REPUBLICAN WEDNESDAY, JUNE ri 1871

water eleven feet in order to keep the canals
I running with the necessary current to sup
| ply the pumps. This will be easily under
stood If we remember that there are ten
feet fall from the river to the nearest drain
ing machine, and even with this fall the
water does not reach the machines as fast
as it should, and if the machines were
placed at the lake, the rains falling in the
heart of the city would not reach the pumps
in less than three hours. In view of this
fact, let me ask your attention to a plan by,
then, Major Beauregard, for the drainage
OF the First District, in which the quick re
moval of this water is provided for. Why
this plan was not carried out by the Commits
sieners of the First Drainage District be-
fore the war, l do not know, but to this
neglect and this alone / attribute all
damages to this district from overflow since
1852
If the engines are placed as indica ted in
General Beauregard's plan, the lift might
be taken at six feet. The quantity of wa
fer deposited by rain is fifty inches per an
num-one hundred and three days in the
year being rainy days; that is to say about
half an inch per rainy day. But as half
the rainfall is carried off by absorption or
evaporation, we have to remove by pump
ing only twenty-five inches per annum; and
If we take the space beyond the ridge
which we refer to, and which is Il, 900
acres, it will give 1883 ,000, 900 cubic feet of
water to be raised annually or 1896, 1886, 02l
tons. steam engine of eighty six horse
power will raise this quantity of water six
feet in one hundred days of twenty -four
hours and would consume
Eight hundred and twenty-six tons of coal,
az % per Ton p diso
Engineer and fireman. Observation-Disclosures. 2l6t
contingencies. 0OO
Total per annum to drain Il, 900 acres . : $50
Or nearly ffty-fve cents per acre per an
mum.
This calculation is based upon half the
average rainfall, but during storms | have
known of six inches falling in twenty four
hours, and in occasional storms four inches
have fallen in one hour. While in this cal
culatiOn we are removing but One-fourth
inch in twenty-fOur hours, and the cost per
annum is ttty-tive cents per acre, or one
horse power to 1872 acres. During storms
machinery would be required for probably
twenty-four times this quantity, or 2064
horse power for Il, 900 acres, or one horse
power for $50 acres. Hence we may say
that the pumping power provided should
be at least one horse power for every five
acres during hard storms; aud if we say
our city contains 100000 Inhabitants we
are required to pump, in addition to this
rainfall, five cubic feet of sewerage, or
oUU,UUU4o=1, oUU,OUU cuOlc 1eeU ually, or IN
one year SAT 500, 900, which is equal to
1916, 22S' tons of sewerage per annum.
The pumping of sewerage costs S.0O02l4
per ton lifted six feet. Therefore 1920,
DISKS .000 2l4=$3, 269 TIA.
Tons.
Quantity of rain falling per annum
upon area to be drained, say 30
O0o acres Observation-Disclosures. IS. 1862 GID
Sewerage Observation-Disclosures. l5216,2 23
Total number to be pumped. 49,. 81 233, $40
Cost at s .0O02l4 per ton. 10, SIS IL 100
RECAPITULATiON.
Cost of leyee of earthwork. .......... Sl,l1O,720
Cost of land for leyee of earthwork.. As. 325
Total. Observation-Disclosures. 2l6 .545
Cost of wall of masonry. ....... $l,040, $40
Cost of land for wall of masonry. 1000
Total. ACKNOWLEDGEMENTS. $lo4lt 40
Annual cost of pumping 81 SIS 1l-lOe
Hoping yeu may find this of some service,
remain,
Your obedient servant,
JOHN ROY,
Engineer and Architect.