FLOOD03704

• County: Clear Creek
• Community: Georgetown
• Stream Name: Clear Creek
• Basin: South Platte
• Title: Flood Hazard Evaluation 6th to 7th Streets
• Date: 10/6/1977
• Prepared For: Georgetown
• Prepared By: Georgetown
• Floodplain - Doc Type: Floodplain Report/Masterplan

The in~bank flows up to the "spillover" elevation
onto 6th Str.eet whose depth at the bridge opening is
about 6.5 feet provides a,n "in-bank" flow downstream
of 6th Street of about 600 cfs; that, combined with
the 250 cfs from the overflows from 6th Street gives
an 850 cfs flow at 7th Street.

As shown by the cross sections 6 and 7 and the
corresponding in-bank flows on the profile, the area
behind the post office is not affected.

C. In-bank flows above the 6th Street bridge opening,
increasing up to about 1200 cfs, a less frequent flow,
(continue to) over-flow down as well as across 6th
Street from the bridge north to Rose Street. Over-
flows across 6th Avenue will increase to a maximum
depth of about 1.2 feet with some flows going down
Rose Street..

The combined in-bank flows from 6th Street down to
7th Street will consist of some increase of in-bank
flows from 6th Street of about S50 cfs with excesses of
6th Street overflows of about 250 cfs. with a total
on 7th Street in Clear Creek of about 1100 cfs.

These conditions as given by the cross sections
6 and 7 with the in-bank profile indicate the par-
ticular area for the "structure" use as not being
affected by these flow conditions.

D. Infrequent flows of 1200 to 2500 cfs flows in
excess of 1200 cfs above the 6th Street bridge
will in pa:tt overflow westerly toward Brownell
Street. The extent of this overflow in proportion
to the continuing overfows down 6th Street is estimated
at 20% of total flows above the 6th Street brdige
opening.

Corresponding increases in 6th Street overflows
from Argentine to Rose Street from a 2500 cfs above the
6th Street bridge, will result with in-bank flows of
about 1000 cfs by the post office and accwnulating
over-flows from Bronnell as well as from overflows
from 6th Street with their combined flows at 7th Street
of about 2000 cfs. The difference of about 500 cfs
overflows down Rose Street and adjoining areas else-
where down below 7th Street.

These conditions shown on the cross sectionb and
profile sheets indicate the particular area behind '
the post office not affected by either or both the in-
bank and overflows from the infrequent flow of 2500 cfs.

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