FLOOD09312

• Designation Number: 370
• County: Crowley
• Community: Ordway
• Stream Name: Local Drainage
• Basin: Arkansas
• Title: Floodplain Study and Master Drainage Plan - Ordway, Colorado
• Date: 6/1/1987
• Designation Date: 7/1/1994
• Floodplain - Doc Type: Floodplain Report/Masterplan

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reble 12. Co"llarlson of Conceptual Alternetlves.

4'0

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Evaluation crIterIa

canments

Alternative - Conveyance - Historic Path
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Alternative - Diversion System
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Alternative - Detention pond System
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Cost

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Flood Control

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Constructablllty

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~erations
and Ma i ntenance

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Land Use

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Land Acquisition

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Impact on Existing
ut IIltles

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Local PartIcIpation

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Flooding along Otero
and Arkansas e Ilml nated.

Closed culverts are
easiest to maintaIn.

All conduits within
existing rlght-of-ways.

None (See Comment)

lo-Yr. - 52,961,360
10o-Yr.- 53,961,000

Flooding along East Flow
Path unaf fected wi thout
culvert under railroad.

Two railroad crossings
open-cut is doubtful.
Large d I aneter sewers
probab Iv not constructab Ie
wIth adequate cover
(10o-yr.).

Large di ;;meTer stonn
sewers wIll requIre
relocatIons of water
and sewer.

Large diameter storm
sewers oUTS Ide of Town I 5
construct1on capabIlitIes.

lo-Yr. - 52,464.500

FUTure development flows
are routed away frcrn a
flood prone area.

lo-yr. system uses small
dl mleter stann sewer and
overflow channel within
existing rlght-of-ways.
ExistIng concrete box
ranalns In Central BasIn.

Closed conduit are easy
to maIntain.

All condu Its wi thin
existing rlght-of-ways.

None (See Comment)

Sma II d I ","eter storm
sewers wI II requIre
relocatIon of water 11 ne.

1 O-yr. system
constructab Ie by
Town forces.

100-Yr. - 52,806,200

OVerf low I n excess of
1 o-yr. des Ign frequency
must be channelIzed to
prevent overland floodIng.

loa-yr. system difficult
to I nstall due to pipe
cOler cons Ideratlon.

Overflow channels In
lo-yr. design wi I I require
twIce yearly maintenance.

Large d I5neter storm
sewers outside of Town's
constructIon capab Illtles.

Peak f I ow to Central
Basin eliminated.

lo-yr. system uses smal I
dl aneter stonn sewer and
overflow channel wIthin
exIstIng rIghT-of-ways.
ExIsting concrete box
remains In Central Basin.

Closed conduIts are
easy to maIntain.

AI I conduits within
exIstIng rlght-of-ways.
Multiple use potential
exIsts at pond sfte(s).

None (See Comment)

Sma II d I o5lleter stonn
sewers wI I I requIre
relocation of water lIne.

10-yr. system
constructable by
Town forces.

lO-Yr. - $2,510,520
loo-Yr.- 52,782,860

Overflow structures must
be provl~ed downstreMl of
pond.

OJt le1" of pond mu st be
designed with multl-
frequency outlet ~nd
emergency sp IllwalY.

Twice yearly O&M minimum.
f.bre frequent O&M dependent
upon number of ra I nf alii
events In season.

Utnd for pond must be
acquIred at faIr market
value.

Large dl~eter storm
sewers outsIde of Town's
construction capabllltl6s.

Detention concept applies to
Central Flow Path only.

Northwest dralnageway assumed
In place for al I alternatives.

The sma Iler the lac IIlty the
easier to control the
construction.

street pavIng and curb and
gutter recommended along with
storm sewers to prevent the
build up of sediment In pipe.

All alternatIves require
right-Of-way del loeatlon and
acquIsitIon for outfall
channels to Lake Meredith.

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