The Redwood gazette. [volume] (Redwood Falls, Minn.) 1873-1940, 1893-02-16

ton, and be discharged into the river
below Burmeister's milldam. There
are several practicable routes for an
outlet sewer through this private
property, and when the time comes
for the construction of the work, it
will be an easy matter to select several
routes which will be arranged in such
manner as shall accommodate the
property and improvements around it.
That rock cutting will be encountered
in almost any direction between the
intersection of Bridge and Minnesota
streets to the river is certain, but
along any route the sewer may be laid
in a shallow trench with an embank
ment over it to properly protect it
from frost; probably six feet of cover
ing would be sufficient.
The system of storm water sewers
has already been referred to. The
main sewer will be along Chestnut
street with branches on Washington
and Mill streets, extending in each
case two blocks north of Chestnut and
one block south. The extent of the
watershed tributary to this system OF
sewers is shown on the map by shad-
ed blue line. 1t is believed that the
storm water can be carried through
surface cutters, from the outskirts of
this watershed to the nearest catch
basins as indicated on the map, with
out annoyance or damage. No plans
have been made for the drainage of
other portions of the city lying out
side of the shaded blue line, for it is
believed that, at the present at least,
the surface water can be safely and
effectually gotten rid of oyer the sur
face along the shortest routes to the
river.
CAPACITY OF SEWERS.
All sanitary sewers throughout the
city will be 8 inch pipe except the
Washington street main sewer from
the outlet to Fourth street, which will
be of 10 inch pipe. All of the branch
sewers are largely in excess of required
size, but experience has shown that it
is not wise to construct less than g.
inch sewers. Where the size has been
determined by calculation, it has been
assumed that the amount of sewage
required to be carried off would be
equal to the water supply; this has
been taken as at the rate of 100 gal
Ions per person per "a hours, and six
persons to each -25 foot lot, and fur
Their that this volume of sewage would
reach the sewers at the rate of two
thirds IN 8 hours, and that the sewers
when CARRYING this amount should
flow out from one-half to twothirds
full. The storm water sewers have
been proportioned for the removal of
a rainfall at the rate of two inches per
hour assuming that one-half of the
rainfall would be collected and find
it's way into the sewers within the
duration of the time of rainfall. It is,
1 think an ample assumption and yet
one that is not mere than it will be
wise to provide for.
DEPTH AND LOCATION OF SEWERS.
Sanitary sewers will be laid about
Z feet deep as minimum in the resi-
dence portions of the city, and about
9 feet in the business portions. The
depth is not constant but will vary
with the undulatiOn of the street sur
face. The maximum depth of cutting
will be about 10 feet and on the
Washington street main sewer be-
tween Second and Third streets,
deep cutting is necessary, and
to less degree at some few other
places where the sewers are cut
through ridges. This excessive cut
ting is not serious matter.
The plans show house connection
chimneys to be used in all deep sew
ers; these will be put in at the time
the sewers are built. and arranged so
the house connections when made
need be laid only at convenient
depth, ma king the house connections
cost no more opposite a deep sewer
than where the sewer is of the average
depth, if it is assumed, as should be,
that the cost of these chimneys are
included with the cost of the sewer.
The storm sewer will be shallower
than the sanitary sewers, being a min
imum of five to six feet in depth and
a maximum of ten feet. The location
of sanitary sewers will be in the CEN
ter of streets except along Broadway
street where a twin sewer has been
shown, i. e., one ON each side of the
street and about Is feet from the
property line. This has seemed to be
better arrangement for this wide
street than single sewer; it will cost
more but the excess in cost will be
offset by the reduced cost of making
transformations, and the twin sew
ers are somewhat shallower than a
single sewer would necessarily have
been. A similar plan has also been
arranged for that portion of Mill street
between Second and Third streets.
The location of the storm water sew
HI ~ no ~ I