The Express.
London, England, 1853-10-21 00:00:00

THE EXPRESS, FRIDAY EVENING. OCTOBER 21, 1853.

METROPOLITAN COMMISSIONERS OF

SEWERS.

-

A special meeting of the Metropolitan Commis-
sioners of St wers was held yesterday at their office, Greek.
street, Sobo, to receive reports from their engineer, J. W.
liazalgette, Eiq , and their consulting engineers, Sir W.
Cubitt and Robert Stephenson, Esq., on the high level line,
fur the interception of the drainage north of the Themes,
and on the intercepting lines south of thiariver.
The commissioners present were Richard Jebb,
chairman; Lataence Redhead, Esq., G. Spencer Smith,
Esq., and Colonel Dawson.
The CHAIIMAN stated that the principal business of the
day was the hinging before the board the reports cf the
engineer and the consulting engineers which had been re-
ceived by two committees of the commissioners, and adopted
by them, and which would be now submitted to the board
for adoption.

The reports of the engineer was ss follows:
NORTH SIDE OF THE THAMES.

" ItACKN111131;00iT OR, NOIITHIIIIX---11101C Lsyaa
INTERCIPTINO SEWIIIL—Tbe "Hackney Brook; or,
Northern High Level laterceptiog Sewer" is one of those
urgent works, for the immediate execution of which you
have recently applied to parliament for powers to borrow
money ; nor can the importance of this sewer, in consider-
ing the drainage of the metropolis, be over-estimated.
It will divert the whole of the sewage and flood
waters of 14 square miles of the upper districts,
from the low districts, and from the River Thames;
thereby reducing the sixes and cost of construc-
tion of the sewers in the low districts, and prevention the

destruction of property by floods as at present. Fur in-
fitsnve, the Fleet Sewer is now overcharged by the
amount of drainage falling into it; it is uncovered
for a great part of its length, through w dense popu
lation; and, in other places, it has fallen in, and has
been temporarily repaired but the commissioners have
_ _

. ,
ever been able to apply an effectual remedy to it, on ac-
enint of its present defective route, and the enormous cost
of rebuilding so large a sewer in a more direct line through
a crowded population; and as it has always been intended
ultimately to divert its contents from the Thames, such a
work could only have been of a temporary character ;
whereas now, by the diversion of the upland drainage these
difficulties will all be removed, and it and many similar
sewers reduced to economical and permanent works. The
amount of drainage received by this upper line will govern
the sizes of the lower lines of intercepting gowns ; and as
parliament has now sanctioned the construction of a tunnel
railway along the New-road, which will intercept our
present main lines of sewers, and necessitate the immediate
construction of an intercepting sewer along its route, this
upper line is rendered the more immediately imperative.
Tuis upper sewer will be in itself a complete and perfect
work, asd independent of any other intercepting sewer : it
will afford an advantageous means of flushing and cleansing
the sewers in ail the low districts above which it pares,
and thus improve their drainage; end it will relieve the
neighboathoods of Stoke Newtonian, Kiogsland, Claptage
and Hackney, from the nuisance of an offensive open sewn
known as the "Hackney Brook," and the latter places
from frequent inundations. The route of this work, which
I have now to submit for your consideration, commutes'
with a sewer 46 in diameter, by a junction with the
4 feet circular sower, now constructing by Meters. Rigby as
the outfall for the Hampstead drainage, in tloo line of the
open Fleet Sewer; its inclination being lin 72. It passes
along Gordon House-lane' crosses the Highgate-road
at an inclination of 1 in 134, and intercepts the second
brooch of the Fleet sewer, being at this point 6 feat 9 inches
in diameter. It then passes across the fields into the
Tulnel Park-road, turns down the Helloway-road to its
junction with the Tullington-road ; at this point its size
is bureased to 10 G in diameter, and it islet(' at such a level,
as to enable it to receive • branch from the Edgware road
and Regent's-park, diverting the waters of the upper por-
tion of the Rattelegh and Kings' Scholars' Pond Sewers,
and again int, rcepting the Fleet Sewer at Kentish Town.
From the Holloway-road, it passes under the Great Nor-
thern Railway, and New River Cat, biking nearly the same
direction as the present open Hackney Brook sewer, far
which it will set as a substitute, and falling at =inclination
of 1 in 476 to the High-street, Stoke Newington, near to
Abney Park Cemetery, where its sue is increased to
11.6 in diameter. It then passes along the Rectory and
Amherst roads, to Church-street, Hackney ; and from this
point it is increased to 12.6 in diameter, and its inclination
is lin 1,320. Thence it crones under the East and Woe
India Dock Railway, along Albion-road, West street, and
through the Victoria-park, and under Sir George Duckett's
Canal, up to which point it is kept up to such • level, that
it may be carried over or under the River Lea Navigation,
or the sewage may be diverted from the point at Sir George
Duckett's Canal down below the Lea Navigation, at Fong
Mida, retaining the present as a flood outlet; or the:point se-
lected would afford an advantageous position fur the erase
Bea of sewage manure worlu. With all these alternating
held .n view, it is proposed for the present to terminate this
work with two parallel culverts, each 7 feet G inches in
height, by 8 feet in width, discharging into the River
Lea at the present Hackney brook out-fall.
This sewer is kept at such a level (for the purpose
of being carried over or under the River Lea, and discharg-
Inuit high water by gravitation), that a portion of the
drainage of the Hackney marshes cannot be tamed into it;
thin must either drain into the Lea, as proposed by Mr.
Forster, or eventually be carried into the low level sewer,
to be raised by pumping. It is further proposed to fix tide-
gates at the mouth of the present Hackney mash open
sewer, to prevent the ingress of the tide, and by this means,
and the di ion of the upland sewage from it, to prevent
the floods to which the Hackney marshes are now sub-
*ted The estimated cost of the whole of this work, from
Kilburn and Hampstead to the River Lea, and a
branch to Four Mills, will be about 271,290 L,
and the probable met of that part of it which it is
now proposed to execute, will be about 181,290 i.
I submit herewith a section of the proposed sewer, • map
slorw.ng its direction. by the red line marked upon it, and
the branch from the Renelagh Sewer, and the alternative
outlets proposed to be added to it hereafter by dotted lines;
the areas which would drain into this sewer being coloured
yellow upon the map, and amounting to about 8,913 acres,
or 14 square miles.—J. W. BAZALOITTE.
BOOTH SIDE OF THE THAMES.

SURD= AND KENT DUAlNAol.—Pursuant to your in-
structions of the 20th ult., I have, in consultation with Sir
William Cubitt, prepared a design for a high level or catch-
water sewer, which, is conjunction with the low level
sewer (the plans for which have already been laid before
you), will complete the main features of a design for the
effectual drainage of the metropolitan districts on the south
side of the Thames, and the diversion of the sewage to a
lower point in that river; whence it will admit of still
lurther removal from the metropolis, u soon as the com-
missioners shall be enabled to carry out the necessary
works. In preparing this design, it has been sought, as
far as practicable, to comply with the resolutions of the
nrinmissioners in 'KO, communicated to their engineer,
Ids late Mr. Forster, on the subject of the main
drainage ; and ill describing tip proposed scheme, it will be
reseenary, tint, to call your Farticular attention to the na-
tural features of the district to be drained, which is repre-
sented by the lc-wino:is respectively coloured green, pink,
and blue upon the accompanying map, and which covers an
area of aboat 24 square miles. The urban districts and
more closely populated suburbs are bounded on the north
by the River Thames, on the east by the River Ravens-
bourne, and on the west by the River Wandle ; the southern
boundary being a summit, or water-shed level, about
Mitcham, Streatham, Norwood, and Sydenlinm. The
River Thames now receives the drainage of this district
from the llcatliwall, the Effra, the Battle-bridge, the
Great St. John's, the Duffield, the Earl, and several minor
sowers, along its course, for a length of eleven miles be-
tween the outlets of the rivers Wandle and Ravens-
bourne. It is not proposed to intercept the rainfall
upon the lands adjoining these two last mentioned rivers:
they will continue to receive it as heretofore. But it is pro-
posed to divert from thou hads, as far as practicable,
the drainage of such roads and buildings as may be built
upon them. The northern half of the entire area, corn
pricing the districts coloured pink and blue upon the map, is
mostly urban ; and its general surface varies from the level
of Trinity high water to 6 feet below it. This tract has,
doubtless, at one period been a marsh covered by the
waters of tho Thames, although many of the houses
upon it have now basements and cellars below the ground.
The southern half, coloured green upon the map, is
suburban, and its surface falls rapidly towards its
northern or lower margin, from en elevatton of 350 feet
higher; so that during Leavy rains the floods from the

whole of this upper district descend with peat rapidity
into the sewers of the two lower districts; and the mouth6i
of those sewers being closed by the waters in the Thames,
for about eight hours each tide, the sewers t emselves
moreover being insufficient to stop 00 storm waters, the
result is, that during that period the lower districts are .
flouded. It will be evident that it is impossible to maintain 1
• coutinual and unintermittiog flow in the sewen et the two
lower districts, or to drain the cellars and subsoil, slid
make them dry and healthy, without the aid of pumping.
The first object, therefore, has been, so to intercept the
waters from the suburban, or high district, as to carry
off the largest passible amount by gravitation ; and
having thus rehired the low districts from periodical
inundations, whereby their size is reduced to a manage- '
able limit, to grid with them as hereinafter describea.
The high level intercepting sewer commences at the north-
, west corner of Clapham-common, being of the ordinary
form (3 man. 9 sec. yt, 2 rein. 6 arc.), and falling at the rate
I of 1 in 341 to its juuction with its northern branch, at the
point marked B on the accompanying map; its route to this
I point being through Clapham, Park-road, Acre-lane, and
Cold Harbour-lane,where it iatercepts the Litre Sewer near
the Brixton-road ; its size increasing in proportion to the
amount of drainage to be received by it, up to 9 feet 6
inches in diameter at the point B, where it receives the
drainage from 2,20 t) acres. From this point the main line
falls at the rate of 1 in 1,760, or 3 feet per mile, to its outlet.
And from the junction with toe northern branch, to the
juncion with the southern branch, viz.. betwecu B and D,
it is 12 fact in diameter, and drains 3,5.,0 acres; its direction
being through Cold Ilarbourolane, Love-walk, and fields
to the point, D, in the Lyndhurst-road, where it rev:lees
the southern branch. From this point to the outlet, it is
increased to two parallel culverts, each 11 feet in dimmer,
passing mainly through fields and garden ground, and un-
der the Brighton taut North K•nt Railways, near N. se-
eress Stations, to the mouth of the Ravenshourne, at Dept-
tord-creek, iLl'O which it will discharge the drainage from
7,850 acres by gravitation, it high water of tau highest
tides. The northern branch commences with a fewer 4
fret in diameter by a junction with an existins sewer ,
'
in Rectory-grove, Clapham • and it falls at an iuelination '
of 1 in 175, through lArkball-lane, to Unioncoad.
Here it increases to 6 feet in dianirtar, and falls to its
junction with the oasis line at the point B, in I
Cold Harbour-lane, at the rase of 1 in 1,472. again I
intercepting the Ehrra Sewer at a lower point in the Brie-
ten-road, and dthinicg t 3.50 acres through a 7-feet-sewer.
The southern branch, or Ethos diversion, commences by •
junction with the lies sewer at Crorted•lane, near Dul-
wich. It fails, at an inclination of from lin 273 to lin
100, in a direet line, to its junction with the main sewer at
the point D, in the Lyndhurst-road; being 9 feet in dia-
meter, and receiving the drainage from 3,100 aczes. These
branches ass imporeaut parts of the high level sewer, and
without them it will not answer. In particular tie southern
branch will save the covering of au equal length (about 2
miles) of the present open Fifes sewer, the waters of which,
instead of descending by a circuitous route, and with a flat
gradient, into the lower dirricts, will ho diverted at a high
level to a point nearer the outfall; and thus the rise and
cost of the upper portion of the main line will be reduced to
one half of what would otherwise be required, whilst a deep
outran for a new district now subjected to floods, namely,
Dulwich, will be provided. Taking the more comprehen-
sive view of the drainage of the whole area, it is proposed
io extend and slightly aster the design fir the low level
sewer laid before the committee,on 20th ult., so as to include
the drainage of 11 attracts and Battersea-fields. The present
scheme commences with a circular sewer, 5 feet in diameter,
at the level of the bed of the Facciabrook, Battersea. It
passes along Battersea-road, under the South Western Rail-
way, along Priory-road, Lansdowne-road, and the Clapham-
road, to St. Mark's Church, Kennington-common; up to
which point its inelinahon will be 1 in 1,760, or 3 fret per
mile, and its sere will then have beau increased to 8
feet in diameter. From this point it proceeds in
the direction of Mr. Footer's line by the side
of the Surrey Canal, to Old Kent-road, et an
inclination of 1 in 2,112, or 2 feet 6 inches per
mile; being at this point 9 feet in diameter. It
then proceeds Moog the Old Kent-road, in Culd Blow-lane,
where it I Mr. Ferster's lice, taking it direct course
across the fields and market gardens, under the Brightou
and the North Kent Railways, along New Ditiglaastreet,
and Griffin-street, to high-street, Deptford; its inclination
for this length being 2 feet per mile, or 1 in 2,640, and its
size 10 feet in diameter. Up to this point it receives
the drainage from 4,450 ecru, coloured pink upon the
map. At High-street, Deptford, its size is increased to
12 feet in diameter, being intended, eventually, to receive
here an important branch sewer from the Lower Deptford-
road, which will divert from the Thames the drainage
of about 3,300 acres, coloured blue wren the map. The
main line then passes between the Gas and the Vitriol
Works, near the Greenwich Railway, and under Deptford
creek, to a vacant piece of ground, well adapted for a
pumping station, or for sewage manure works, or for con-
tinuing the line at some future time further eutward. The
lift from the bottom of the sewer to Trinity high-water
mark, would here be 30 feet; and from 1,500 to 2,000
horse power would have to be provided at the pumping
station. The length. of the proposed sewers would be as
follows:

MO Level Sewer. Miles. Feels. M. F.
Main Line G 2

North Branch
South Branch

Total
Low Level.
Main Line 7 4
North Branch

Total

9 7

Grand Total 2O 2

The sections of these sewers are of a favourable cha-
teau : their inverts generally average from 20 to 30 feet ,
below the surface; and a very small portion of the work ,
will have to be tunnelled. Careful attention has been paid ,
to the character of the surface under which the sewers are ,
to be constructed; ornate property and houses have ,
been avoided as much as possible; but, owing to the streets
bring irregularly laid out, it has not been practicable ,
to effect this altogether, and in such cues the compara-
tive
value of the property has been duly considered.
It will be observed that, to says the permanent cost of
pumping, the gradients of the low level sewer have been ,
reduced ; but the increase in the size of a sewer ,
compensates for a loss of fell; and the sewers will still
maintain, through their whole length, a velocity of current
varying from 11 to 2 miles per hour, with the ordinary flew
of sewage, and during rains that velocity will be increased.
In this sewer there will be a constant current of a large
body of water, so that the average velocity will be sufficient
to keep it clear ham ordinary deposit; but there will also
be a good opportunity of Bushing it, together with the other
'sewers in this district, from the catchwater sewer mid the'
Thames at high water. The minimum velocity of current
in the high level sewer will be about 21 miles per hour ;
whilst at the upper end it will be considerably more. The
size of the MUM ACM propond are larger than any
heretofore recommended to the commissioners; sod I
would here beg leave to refer to that part of the tepors
of Mr. Heywood and myself, on the Great London Drain-
age Scheme, wherein we argue,—" That the drainage
of those portions of the Metropolis at present re
quiring a deeper outfall, must not be made de-
pendent upon any scheme of interception, unless such
scheme is adequate to carry off the Taiwan as well as the
sewage from them. It therefore follows, that whatever
scheme of interception is eventually adopted, if it be short
of such capacity, the sewerage and drainage of the metro-
polio must be perfected and completed independently of
t." If this reasoning be sound, it is manifestly more
economical to construct one work which will answer
eve,y purpose, than to complicate it by the exe-
cution of duplicate sewers, in order to gain the same object
which may be obtained by ens; and it remains only to
show that these sewers are sufficient to carry off the
rainfall, as well a. the sewage, hem the districts for which
they will he the outfall. An avenge of an annual rainfall
amounting to 30 inches, added to the maximum daily haw
of sewage, would give only 3,000 cubic feet per minute
upon the upper district, and 4,000 cubic feet up the lower
district, whilst extraordinary thundet-storms, amounting to
one or two inches in an hour, are recorded ; these. however,
generally occur during the hot seasons, when the ground
absorbs and the air evaporates a large portion of the rain.
Such storms are generally partial, covering but a small dis-
trict at one time, and are never of long duration, so that the
whole of the waters that have fallen upon the district do not
reach the outfall sewer until after the storm has abated ;
and a small portion only of the sewer being pre-occupied at
the commencement of the storm, the remaining portion
for some time stores the flood waters. A heavy and
uniform rain of long duration is probably the most severe
ordeal to which sewers are subjected, when, the ground
and the air having become charged to their full extent,
absorption and evaporation abstract but little from the
sewers' and the feeder sewers, having alto become charged,
would be delivering to their full extent. The largest
quantity of rain which fell in London in oae day during
the wet season of 15.52, measured 11 inches ; but storms
atnount:ng to 21 in. in a day, sithough of rare occurrence, have
been recorded, and these would deliver into the high level
sewer 43,000 cubic feet per minute, whilst it is capable of
discharging upwards of 46,000. The low level sewer will
discharge 21,400 cubic feet per minute ; and it is here Pro-
posed that the existing main sewers in the low districts
should set as reservoirs during such extraordinary storms.
From their construction, and the remarkable flatness
of their level, they are peculiarly adapted to this object ;
and it is estimated that, oar these occasions, they would
store the surplus flans without the rising of the latter to
an inconvenient height, and would again deliver their con-
tents into the names at low water, or into the intercepting
sewer, as it became free to receive them. Thus the provi-
sion of engine power for such rare occasions would be saved,
and the existing sewers made available. At present it would
s erhaps be premature to enter into the details of this
scheme; but there arc two important points which will
es quire your early attention, viz., the engines to be em-
ployed, and the m•nle of ventilation of the sewers. I would
therefore suggest, that I should be authorised, at an early
opportunity, to visit some of the beet and most efficient
pumping and ventilating establishments, and report to you
further on these subjects.

The estimated cosi of this work will be as follows:

High level sewer, main line, 195,800!.; north branch,
20,400!.; south branch, 42.0001.-268,0001. Low level sewer,
main line, 140,0001.; north branch, 39,000/.; engines,
pumps, &c , 100,0001.; land, buildings, 6,:e. required for
the permanent establishment, 100,0001.-3; 9,0001, ; total,
637,0001.—J. W. t AZALGETTL.-6:11 Oct., IM3.
The reports of Sir William euhitt and Mr. Robert Ste-
phenson, M.P., the consulting engine. re, were also r.ut.
They cmcurred generally in the plans of Mr. Bocalgutte.
'l' he CHAIRMAN said that he only wished to observe that
the reports contained very large estimates, and that the
commissioners had not at present sufficient powers la raise

the necessary funds. They had, however, ohtsined rcwers
in the last session which enabled them to raise 200,000/. for
draivage purposes, and they proposed, as soon u they had
raised funds, to commerce one or both of the works men.
tinned in the reports immediately. The system on which
they would proceed would depend on several circumstance',
such as the raising of the money, the season of the year, ACc.,
and they would not pledge themselves until after the
meeting of another court as to the time at which the works
would be commenced; but their wish and intention was to
commence them forthwith, and proceed wit% them as far as
their funds would alio •. lie wished to mention that the
scheme of drainage on the south of the river world include
the ci.strict whicn was bounded en the west by the Fa:can
Brook, although it was not mentioned in the rerorts.
Colonel Dawsort amid that he wished it to be understood
that the reports were unanimously adopted by the com-
mittees.