Decorah public opinion. (Decorah, Winneshiek County [Iowa]) 1895-1928, 1920-07-14
THE DRY RUN
IMPROVEMENT


invariably asked, is, How are you
coming along with the creek?" 1t is
in order to give an idea of what
has been done and what remains to
be done that this is written.
The engineers have been busy
gathering together data sufficient to
get out the following:
/. Detail map of the food area,
scale ] inch-50 IT.
2. Map OF the improvement dis
trict, scale / inch-200 IT.
8. Map of the entire drainage
area showing the creek and it's
branches, scale / inch -1500 #.
4. Cross sections of the creek
every 100 feet.
5. Profile of the creek in the
city.
6. Profile of each bank, etc.
The field work was completed
about two weeks ago, and the Office
work is now well under way.
The detail map mentioned under
number one above, if placed on one
sheet would be some twenty feet
long. and shows the creek as, it is
at the present time together with all
houses, sidewalks, curbs, trees, ont
buildings, etc, in fact, everything
that can in any way influence the
course of Dry Run or affect the. re
location as to cost, present or future.
The notes for the survey covering
this map, fiji four note books, or
field books. Of seventy-fve pages
each with some rs lines to al'page.
Every line means n separate shot or
observation to be computed and plot
ted; This gives hut ia faint idea of
the mass Of detail: work noaneeted
with this one map ,alone. However,
1t is absolutely essential t0,Ihavs
this information, both for. the, con-
tractor and for the city. The con-
tractor has to have it in order, tc
know how, when, and where to start
the work. and how to dispose of the
equipment he will have to use, The
city needs it in order to handle the
assessments in a rational way, and
in order to know where they can go
through with the least trouble and
confusion.
The map of the improvement dis
trict, as its title indicates shows
that portion of the city most direct
ly affected, together with the chang
es in alignment of the creek. This
map is general and is to give com
rrehensive idea of the work involved
and is not supposed to show any OF
the details covered by the larger
map.
Item No. 8 above, Map. of the
drainage area shows the entire
area drained by Dry Run--some
twenty-five and one half square
miles. This is for the purpose of
computing. One can readily. see
that in order to know what amount
OF water to provide for, it is neces-
sary to know what the area is upon
which the rain falls. 1t is not
enough to know only what the area
is, but other factors such as the
Character of the soil, state of cul-
tivation, slope, etc., must be taken
into consideration also. ID might be
interesting to state that the drain
age area reaches from about two
or three miles this side of Ridgeway,
south through Conover and back
along the ridge. The general shape.
Is that of a triangle or fan, with the
narrow end in the city of DEBORAH
and the other end through Conover
ard running north.
The cross sections are about 4 go
in number, and involve the taking
and plotting of an average of twelve
shots for each one. From them are
computed the present maximum and
minimum cross sections. In plotting
these fifty yard roll OF profile paper
was used and few cross sections
had to waitJuntil more paper was OBJ
tanned. These are drawn to scale
and the area obtained by the use of
a planimeter, or mechanical inte
orator, as it is sometimes called. BY
means of this instrument, the areas
are read off directly, except that a
constant must be used.
The profile of the creek. shows the
grade or slope snf the present bed,
and provides basis on which to oh
tain the ideal slope, or at least the
possible slope. The profiieiof the
banks shows just what portions, If
any, need levees.
Allof these-maps and -profiies are
well under way, some being com
pleteds1in'lSSn6il. but not mixed in,
others being partly linked in and
partly penciledr in. 1t will be, hut a
comparatively short time until they
are all ready for tracing.
At the time the engineering work