, 1881-06-05
THE WATER-SUpPIY.

| The Legislature wisely took no action on
the scheme to authorize the people Of this
| city to create debt Of ten to fourteen mill
| ions Of dollars to erect Water Works at
| Lake Forest and bring the water By land
| tunnel to Chicago. We print a statement
this morning OF a plan now under exalll-
ination by the Mayor for an increase Of
the city's supply Of wafer. and the rid
dance of the evils of sewage and ice
which so seriously threatened not only the
purity Of our present water-supply, but also
threatened its serious obstruction The pres
ent tunnel was projected fifteen years ago,
when the population Of the city was less than
half its present number. Since then the
tunnel has been duplicated, and still the sup
ply is hardly adequate to the wants Of the
city, and will certainly be insufficient five
years hence.
Experience has also shown radical defects
III the present crib and its arrangement for
receiving water. The inlets to the crib are
only five feet below the surface of the water
of The lake, and of course, 4 direct suction be-
ing furnished, the crib receives into its cylin-
der the water from the surface Of the lake,
together with all that may be floating or car
ried along by that surface water. These ill.,.
lets being near the surface Of the water are
directly under the effects of the ice which
banks up around the crib, requiring last year
the continued labor Of Il large force Of men to
Keep the inlets open. The water at the crib
is only thirty feet deep, and the wash, In the
comparatively shallow wafer. has practically
closed one Of the lnlets, and obstructed a SER
ond one. 4 new crib is therefore necessity
for the future, not only TO increase tile sup
ply, but also to escape the results of the de-
fects in the present one
The plan described in THE TRIBUNE this
morning is to extend the present tunnels
from the present crib to a point six miles
from the shore, where the water is from fifty
to sixty feet deep. At this point it is pro-
posed to build d new crib, or 'aQua-port''
(water-gate), OIL an improved plan. The
architect is the same gentleman who designed
the present crib, and has practical experience
not only Of the defects of that structure. but
knows how to avoid their evil effects,
He points out that the water from the river,
passing into the lake, retains its volume dis
tlllct from the lake to an immense distance:
but this body Of river water, being warmer.
and lighter than the lake water floats near
the surface, and rarely if ever sinks more
than fifteen feet from the surface. 1t will be
seen, then, that when the river water is carried
near the crib, it strikes the inlets to that
structure and is carried by the suction down
into the tunnels. This, the greatest Of all
evils, is guarded against by the proposed
new tunnel, where the water will be fifty to
sixty feet deep, and the inlets will be at the
bottom and not at the surface of the lake,
Even should the river water be carried by
the wind to the new crib, the entrance to the
cylinder will be from thirty to forty feet be-
low any point to which that river water will
sink.
In like manner the same change Of receIv /
ing the water from the bottom Of the lake in
stead Of from the surface will relieve the in
lets from all possible closing or obstruction
By the ice. The ice will not q, to the bottom
at depth Of fifty to sixty feet; the anchor |
ice at that depth will be fluid, capable Of be-
ing pumped. In this way the evil of sew
age reaching the tunnel will be rendered in,-
possible, as will also the danger of obstruc-
ion from ice,
The statement includes general view of
he manner Of constructing the new crib so