The Sun.
London, England, 1867-08-10 00:00:00

water. Such a rainfall may not within the presen
generation again occur. In spite of the relief afforded
by the new intercepting sewers and the provisions
made for the escape of storm waters, there were on
July 25 some exceptional instances of the flooding
of property in the low level districts on the south
side of the Thames. The houses of thu lower portions
of the south side are built within a basin, the rim of
which is the river Thames ; and at high water the
river is 6ft. or 7ft. higher than the streets and 12ft.
higher than the basements of the houses; therefore
no water can run by gravitation out of their sewers
until the tide has fallen. The pumps and intercept-
ing sewers relieve these districts by the constant re-
moval of so much rain as they were designed to
carry off. The surplus can escape into the river
through the storm outlets only when the tide is low.
On July 26 the tide was rising as the storm fell, and
the accumulated reservoir space of the district sewers
not being sufficient to store the surplus water of
that extraordinary rainful until they could get re-
lief the flood rose above th 9 level of some of the
lowest basements. The protection of the low level
districts against such casualties rests to a large ex-
tent in the hands of the local authorities, and it is
their duty to provide-1. That new houses shall not
be allowed to have basements so much below the level
of the river that they cannot be properly drained.
2. That the private drains of all such houses as have
low basements shall be protected by flood valves. 3
That all sewers to be constructed in such localities
shall be of sufficient capacity to store the flood waters
during the time the tide is above their outlets.
A large proportion of the houses in Battersea and
other localities, with respect to which complaint is
now made that they were flooded on July 26, have
been built since the levels of the main drainage sewers
were determined upon of commenced, at so low a
level that they cannot be properly drained, nor have
any precautions been taken in forming their drains
to protect their basements against floods. Several
properties have also been flooded by defects in their
own drains or by other local causes having no refe-
rence to the general system of drainage. There arc
about 80 miles of new intercepting sewers, and up-
wards of 2,000 miles of local or branch sewers, and
it is to these branch sewers, therefore, that we must
look for the storage of about nineteen-twentieths
of the waters of extraordinary floods during the
period of high tide. Now these sewers have not
been formed upon a complete and comprehensive
plan, but they have been the growth of ages, con-
structed from time to time to meet local wants, and
many of them are still very defective. They are
continually being added to, improved, and deepened
by the Metropolitan Board, the Vestries, and the dis-
trict Boards, and, in proportion as these improve-
ments progress, so will the probabilities of the
flooding of the low-level districts decrease. It can-
not, however, be too forcibly urged that there is a
limit to the depth to which it is possible within a
reasonable cost to drain, and this limit has, in many
instances, been exceeded. The intercepting sewers
have more than answered the original expectations
with respect to them ; their soundness and efficiency
can scarcely again be more severely tested than on
the 26th of July last. The pumps were that day
lifting a volume of water equal to nearly half an
inch of rain over the whole of the low-level area,
nearly double the quantity they were intended to
lift, without even such partial failure or accident as
might in a work of such magnitude, and under so
severe a test, have been fairly expected. I submit
herewith several claims for compensation and other
communications with respect to the flooding of pro-
perty by the rain storm of the 26th of July, and I
recommend that the report be printed, and a copy
thereof sent in reply to each of the communications
on the subject, and that the claimants for compen-
sation be informed that this board denies its liability
to make compensation.
" F. W. BAZALGETTE, Engineer."
On the question of how to dispose of the rainfall,
Mr. Bazalgette stated that it was a question of con-
siderable difficulty, and had given rise to much diver-
sity of opinion. That arose front the fact that, while
it was in itself harmless and even advantageous to
the river, it sometimes fell suddenly in large
quantities. These considerations bad induced theo-
rists to advocate that the rainfall should not be
allowed to flow with the sewage, but should be dealt
with by a separatesystemof sewers. This he thought
most impracticable, as it would involve a double set
of drains to every house, and the construction and
maintenance of second series of sewers to every street.
Applied to London it would involve the re-draining
of every house and every street in the metropolis,
and according to a moderate estimate it would lead
to an expenditure of from 10 to 12 millions of money,