FLOOD00689

• Designation Number: 136
• County: Arapahoe
• Community: Littleton
• Stream Name: Slaughterhouse Gulch
• Title: Major Drainageway Planning - Slaughterhouse Gulch, Littleton
• Date: 5/1/1974
• Designation Date: 5/1/1979
• Floodplain - Doc Type: Floodplain Report/Masterplan

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900 cfs or approximately the discharge characteristic
of a five-year storm event. Flows in excess of the design
capacity of the box would overflow the channel to the
north northwest following the general alignment of the
present flood plain. Proposed development plans for the
county shop area should provide a route for the passage
of excess flows to the South Platte River. Although
flood damage can be expected in this area, the projected
damages for the extreme flood event are not excessive as
to generate the necessary flood control structural improve-
ments. Flooding which would be characteristic of the area
between Santa Fe Drive and Prince Street would be very
shallow and could easily be handled with the implementation
of floodproofing measures on the various buildings and
businesses in the area.

Upstream of the box culvert and extending from approxi-
mately Station 5+50 to Rio Grande Street at Station 16+00
a low velocity grass lined open channel is proposed. It
is intended that this channel be implemented with the
development of the city land adjoining Slaughterhouse
Gulch to the north. The channel plan as proposed will fit
nicely with the development plans typical of the Lakeview
Knolls PUD proposed. The channel would incorporate a low
flow channel with a side overbank, providing sufficient
capacity to handle the 100 year storm event runoff. Gabion
drop structures have been incorporated into both the major
channel and low flow channel to step the channel down
through the reach in order to develop the desired lower
velocities. The normal velocity for the design discharge
of 1920 cfs is 7fps with a normal depth of 4 feet in the
overbank channel. The channel should be installed within
an 80' easement which should be retained by the City when
transferring title of the land to the developer. The 80'
easement can be transitioned to a 70' easement in the up-
stream part of the reach as it was intended that portions
of the channel improvements may be extended into the
Denver Water Board Easement, paralleling the proposed
channel alignment. In the upper 250' of the channel
reach, below Rio Grande Street, it is recommended that
the 20 to 30 foot right-of-way be acquired to permit the
extension of the south side slope into the property pre-
sently owned by Geneva Corporation.

The typical channel section is shown on the drawing. A
low flow or trickle channel has been proposed which should
be lined the full length in order that excessive scouring
will not take place during minor and major flows. High,
localized velocities will be characteristic of this area
of the low flow channel. Side slopes have been proposed at
3:1 in order to minimize the area required for the

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