The Sun.
London, England, 1861-10-05 00:00:00

PROGRESS OF THE MAIN DRAINAGE WORKS.

Mr. Bazalgette, the engineer to the Board,
presented his monthly report on the progress of
the main drainage works. It stated that the
objects sought to be obtained by these works were
to intercept nearly 52,000,000 gallons of sewage
which now empty themselves into the Thames,
and by means of covered channels, so far as prac-
ticable, to convey them to points in that river
remote from the metropolis—viz., Barking Creek
on the north side, and Erith Marshes on the south
side. The works in progress were designed to give
deep outfalls, and prevent in future the flooding of
the outlying districts in times of heavy rains. They
were also intended to carry off, not only the sewage,
but the rain which washed the streets, except such
heavy rains as occurred about 24 times a year, on
which occasions the old sewers would act as safc•ty
valves, and let oil the surplus water into the river,
The original estimate of the intercepting scheme
was about £3,000,000, aril, in spite of the rise in
the price of bricks and other building materials, it
was expected they would be completed for about
that sum ; but it would require another half-million
to improve and cover the tributary sewers before
the drainage of land could be pronounced as per-
fected. However desirable it might be, it was not
possible to convey the whole of the sewage to the
required level at the outfalls by gravitation, for a
large portion of London which was densely inha-
bited was several feet below th© level of high water
in the rivee. For that reason the whole area on
each side of the Thames had been :diverted into
three levels, and the sewage was carried as far as
practicable from two of the upper levels by gravi-
tation; but the sewage from the low levels had to
be raised by pumping, by which means the low dis-
tricts would become as dry and as well drained as
the upper districts, and the waters of the upper
will no longer inundate the lower districts. The
maim drainage scheme was commenced in February,
1859, and out of the estimated £3,000,000 works to
the amount of nearly £2,000,000 were now under
contract, and most of them in a forward state and
rapidly progressing. Those contracts embraced
about fifty miles of main intercepting sewers, which
were mostly under ground, but in some places they
were above ground, crossing alternately under and
over navigable rivers, railways, canals, and roads,
and including pumping stations, aqueducts, pen-
stocks, tidefiaps, and other appliances. The northern
high-level sewer, which extended nine miles in
length, from Hampstead to the River Lee, at Bow,
formed a substitute *for the open Hackney Brook
and Fleet sewers, and was now entirely
completed. The northern out - fall sewer,
which extended from the River Lee to
the River Thames at Barking Reach, received
the united streams of the high and middle level
sewers at the Old Ford penstock chamber, and con-
veyed them still by gravitation through two large
tunnels to Abbey Mills, where by a pumping estab-
lishment the low level sewer would be raised to this
'
high lev9l, and thence the whole sewage of London
north of theThatnewou
l 1 flow through three paral-
lel channel
Ito the outfall. This was the largest
contract yet let, and,
treble lines of e unlike others, the double and
ewers would be above the ground,
instead of under it.
These sewers were now in
course of construction
upon a raised bank of con-
crete,y iron aqueducts over seven
and they crossedb
branches of the river Lee, and
passed over and
works under several railways. The were progress
ing rapidly, and the total value of the work done
was about £93,000. The middle level sewer contract
extended from Kensal-green to the penstock cham-
ber, -Old Ford, Bow. It was 1.21- miles in length,
and varied from 4ft. by 2fc. 6in. to l2ft. by Oft:in
diameter. Every arrangement wee being made by
the contractors to prevent incouv,euience to the im.