The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1885-11-02
THE UPPER MISSISSIPPI.
The Northwestern Reseryoirsto Improve
Navigation at st. Paul and Below.
Test Dams Already Built-What They Have
Accomplished Prevention of Floods
Tree Planting as Remedy.
Correspondence Of the indianapolis Journal.


of the West which will be pressed upon the
next Congress. One of these is the plan to
connect Lake Michigan with the Mississippi
river by canal between two rivers of Hi
nois. This Hennepin canal project is not novel.
1t has sustained at least one congressional
rebuff already, and it may expect another. Even
Chicagoans are waking up to the fact that if
they want canal to the Mississippi they must
follow the example of New York and build it
for themselves. The second scheme is a pro-
posal to construct great reservoirs on the upper
Mississippi into which the surplus water may be
turned in flood times, and from which it will be
discharged in time of drought. It is hoped in
this way to reduce the risk of foundations and
to keep the river navigabe throughout the whole
summer. This plan is likely to meet with oppo-
sition on the ground that the upper Mississippi
has fewer claims upon the national government
for the outlay involved IN such work than has
the Ohio. The population and the wealth
affected by food and drought along the Ohio are
much greater; the facilities for the construction
of reservoirs are equally good. On the other
hand if such huge engineering experiment is
to be pushed through at all, the Mississippi may
fairly claim to have the prior right, since it was
first in the field, and work upon its banks has
already begun
The theory Of the reservoir system, as held by
the engineers who have advocated its adoption
for the last fifteen years, involves the storage of
the water not needed for navigation in winter
and spring, the opening of the gates of the dams
as soon as the channel of the upper river begins
to shallow dangerously at the approach of the
dry season, and the release of the impounded
water at such times and in such quantities as to
MAINTAIN a navigable stage as far as Lake Pepin,
fifty three miles below ST. Paul, beyond which
the most formidable distractions arise, not from
variable water supply, but from the nature of
the river and the character of it's banks. The
system for the upper Mississippi contemplates
the construction Of five reservoirs, four to be To-
Gated at the outlets of lakes tributary rivers,
AND one distributing reservoir to receive and reg
ulate the supply from those above; to these are
to be added one dam Pine river, and one on
Gull river. If the system proves a success it
will naturally be proposed to extend it to other
tributaries. The most conservative estimates
made by engineers at the time the project was
first seriously discussed, some five years ago,
united in saying that uniform depth of not less
than four feet Of water at ST. Paul could be Sc
cured by such works. Relying on their testimo
ny, Congress ordered the reservoirs begun. Up
to the present time the work has received appro-
prlations to the amount of $685. 0O0 Mai
Charles j. Allen, the United States engineer in
charge, and j. G. Pyle, of St. Paul, who gave de-
tails or the work of construction as far as it had
then progressed in Harpers Magazine for Sep
TENDER, 1884, have furnished facts with regard to
the present status of the scheme whick are of
interest in view Of the forthcoming appeal for
further aid.
Work upon the reservoirs vas begun in 1882
Three of them were completed ready for opera
ton last year According to Mr. Pyle the dam
at Lake Winnibigoshich, finished in August
1884, and the most important of the three, has
length of l, 100 feet, with height above low
water of fourteen feet. Its storage capacity is
40 600 600 900 cubic feet. The Leech lake dam,
the second OF the series, is g. 500 feet in length
four feet above low water. and has storage ca
pacity Of 22, 600, 600. 900 cubic feet The dam at
Pokegama, storing on its account and also
receiving water released from the two former,
is abo ut 300 feet long and seven feet above low
water. Its capacity is about l3, 000 000 coo cubic
feet.
The dams are built of earth and timber the
amount OF money at command allowing little
stonework except the necessary riprapping. The
drainage basin tributary to the three reservoirs
includes about 3, 800 square miles. 1t was in Oc
tober, 1884, that the practical storage of water
began. 1t is not possible to close the gates of
the reservoirs entirely at any season of the wear
without interfering with logging operations and
with the water-supply of the flour mills at Min
neapois- But between October, 1884 and Au-
gust, 1885, the accumulation of water in the
three test reservoirs about SO 600 600 900
cubic feet, by retention of surplus water only
allowing sufficient discharge to provide for
all the need of commerce. On Aug. 10
of the present year the sluices were
opened for the first time to aid navigation. From
that date the flow was gradually increased, until
upon the Doth of August it had reached a dis
charge of about 1900 cubic feet per second
which rate was maintained up to Oct. l. The
effect upon the river has been accurately
measured at St Paul From fifteen to twenty
days is required to produce any result at this
point from changes in the upper river. From
Aug. to Aug. % the Mississippi fell steadily,
declining one and three-tenuhs feet. On the 23d
the gauge-reading at St Paul became stationary,
and remained SO until the 3lst when the water
surface rose twotenths, maintaining that height
tor the greater part of the month. When the
decline was thus check ed there was nothing but
the reservoir to produce the effect. All the
upper tributaries falling steadily The
Minnesota and the Crow Wing declined until
Sept 10. Pine river Prairie river, every stream
of any size about St. Paul was decreasing it's
flow. No rainfall of any extent was noted. The
change in the Mississippi was almost, if not
altogether, independent of any other cause than
the discharge from the reservoir.
1t is the opinion of Major Allen, engineer of
the works, deliberately expressed, that taking
into account the stage OF water in all the streams
and reasoning from effects produced in previous
years, when the reservoirs were not in existence
although only three dams were in operation, the
river at st. Paul but for them would have beer
ifou nine iucHeS 10 ICOC lower L1dn IL was on
the last OF August; and that, besides thus check
ing the decline, the reservoir water has ma
terially assisted in producing at low water season
an actual rise Of water surface"
The actual gain to navigation is easily under
stood. The average depth Of water over the
Mississippi bars fixes limit of size and carving
capacity for steamers and barges. An addition
of six inches to the depth of the navigable chan
mel represents for fiat barge $50 feet long and
thirty feet wide, an added carrying capacity of
NV no
number of barges in tow, and the practical
value to commerce of the reservoir work begins
to assert itself. An addition of foot of water
gives an additional carrying capacity of 140 tons
for single barge, and on for all kinds of
river craft, according to their shapes and dimen-
sions. More than this has already been accom-
plished by the first experimental work of the
most distant reservoirs. those whose effect is