The Roanoke times. [volume] (Roanoke, Va.) 1890-1895, 1892-03-12


Tinker creek that it have a width OF 25
feet. having hydraulic slope of 15-1OO
per loo feet and grade on the bottom,
as we are informed, 9. 10 per 100 feet.
owing to tho fact that Mr.. Dunlap's
more recent surveys show larger areas
draining through the city than had been
estimated by him before, the sizes of
the drains have been corresoondingly
Increased.
we also recon mend that the drain
now existing in Campbell street be en-
TENDED to Roanoke street and made
large enough to carry lis cubic feet per
second, and that inlets be provided of
ample capacity for the admission of
water to the drain.
To give relief to tho territory in the
vicinity Of Franklin road and John ave-
nue., we are Of the opinion that in the
future 1T will be necessary to carry out
the idea suggested by Mr.. Dunlap, city
engineer. But we recommend that the
sewer be confined to carving storm
water only, and that it be placed in
Fourth avenue instead of Fifth avenue.
Although Lick run will in the future
need to be walled in, it may not BIO
necessary to do this at present. but in
all structures built along its line pro-
visions SHOULD be made for the walling.
be kept open, we advise that walls be
built OF sufficient strength to support
covering. should it over bee ome
necessary to devote the space occupied
by the run for street or other pur-
poses.
we also recommend that all the
masonry for waterways, storm drains,
etc., be laid in cement, and that q
smooth interior surface be given Thorn.
as otherwise the carrying capacity will
be much reduced.
Fourth. We advise, generally, that
sewage be kept from entering the runs
which pass through the city, and that
they be used for storm water only. In
some, and perhaps many cases, it NAV
be desirable to admit some surface
water from the streets to tho sewers.
Overhows should then be provided from
the 1nterceptors by which the storm
water from the district sewers may be
delivered into the runs. To accom-
plish this object, we recommend that a
marginal or intercepting sewer be laid
along each side of Lick run from Tinker
creek to Trout run. That the ono on
the north side be equivalent to a
3s-inch sewer, and that tho one on tho
south side be continuation of the
24-inch sewer.
Above the mouth of Trout run the
iaterceptor on the east side is to be
Is inches, and the one on the west side
Is to be is inches in diameter. Above
tho junction Of Lick and Trout runs
marginal sewers should extend up
Campbell street and Railroad avenue,
as shown on the plan.
We recommend that the intercep-
tors receive only sewage, and that
the. sewers of all parts of tho
city be planned on the separate
system, excepting in few instances as
stated above, whore in may be desirable
to take in surface water. IL the inter
ceptors were designed on tho com ed
system below the mouth of Trout run,
1t would require an equivalent of q
circular sewer at least fourteen feet in
diameter to carry the amount of storm
water provided by the proposed drains.
But sewer of such n form in height
would be impracticable. as either the
bottom would be below the bed of
Tinker creek. or tho top project above
the railroad and the grade of the street
bordering Lick run.
Fifth. With the provisions we have
made for storm water in the Lick run
drain, the northern interceptor proposed
by Mr.. Dunlap extending from Lick run
near the dairy oasterly and joining Lick
run again near Nicholson street, will
not be needed
Sixth. Our attention was called to
caverns said to exist in various places
under the city, and our opinion has been
asked regarding the use of such caverns
as suitable receptacles of sewage and
storm water. We are of the opinion
that such use might prove disastrous.
as sewage would find entrance to under
ground springs used for domestic pur-
poses, as there would DO danger of
gradual obstruction in its assures and as
the caverns would become filled with
filthy offal.
With the introduction of tho sewage
of Roanoke. Tinker creek will become
very foul and an interceptor will event.
ually be necessary along the banks to
its mouth at the Roanoke river. From
the best information at hand we find
that summer flow of $50 to 200 cubic
feet per minute will generally satisfac-
torlly dilute the sewage of a Thousand
persons. Mr.. Dunlap has stated to us
that Tinker creek has an area of AS. 900
acres and q minimum flow of so times
603, 900 cubic feet per minute. In that
case tho sewage of $1,000 people
may therefore DO discharged into it
without giving much offense. The
minimum flow of the Roanoke river Mr..
Dunlap gives MS as being l72 times 60
plus 1880 cubic feet per minute, which
will dilute the sewage of 5O,OOO persons.
Very respectfully yours,
SAMUEL. M. GRAY,
RUDOLPH NJ. Herring.
On motion of Mr.. Watts the report
was referred to the board Of public
works. With instructions to prepare
estimates on the plan of sewerage
recommended, and to report same to
Council at the earliest possible moment.