FLOOD02174

• County: Denver
• Community: Lakewood
• Stream Name: Dry Gulch
• Basin: South Platte
• Title: Major Drainageway Planning
• Date: 7/1/1979
• Prepared For: Denver
• Prepared By: UDFCD
• Contract/PO #: &&
• Floodplain - Doc Type: Floodplain Report/Masterplan

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11

culverts are inadequate to convey annual floods, so the

majority of the flow in major floods reaches the inter-

section on the surface. The surface flows split, with the

majority flowing southerly to Dry Gulch, but a signifi--

cant portion flows easterly to enter the North Dry
Gulch Sub-basin.
Hydrologic Characteristics After Implementation of the Master
Plan: A culvert under Colfax is planned which would convey lO-
year and smaller flows southward to Dry Gulch. Greater
floods would continue to flow partly on the surface and
would split as described. Thus, flows in all floods on
Dry Gulch east of Garrison would be greater than those

which would presently occur. Similarly flows reaching

North Dry Gulch from Dry Gulch will be terminated in lO-

year and smaller floods, and will be greatly reduced in

larger floods.

smaller flows to pass through unchanged. Ten-year and

greater floods will be stored in the pond and the peak

flows discharged will be less than those reaching the

pond. Figure 1II-4 illustrates the value of the deten-

tion storage through use of flood hydrographs.

Location: Carr Street and l3th Avenue (Dry Gulch)

Hydrologic Characteristics Under Present Channel Conditions:

Flow in all floods reaching this area presently proceeds

downstream without change.

Hydrologic Characteristics After Implementation of the Master

Plan: A detention pond is proposed west of Carr Street between

l3th and l4th Avenues. This pond will allow 5-year and

Location: Colfax Avenue between Pierce Street and Balsam Street

(North Dry Gulch)

Hydrologic Characteristics Under Present Cha'nnel Conditions:

The North Dry Gulch flow is conveyed primarily on the

street surfaces when it reaches the intersection of Balsam

Street and Colfax Avenue, and then attempts to flow east-

ward on Colfax. A portion of the flow crosses the median

of Colfax and proceeds southward to a small, undefined

drainageway which also flows eastward. In the Flood

Hazard Area Delineation Report (Reference 1), this drain-

ageway was named Colfax Gulch for descriptive purposes.

This gulch collects flow which passes northward over

Colfax Avenue at Yarrow, Vance, and Reed Streets, and

the entire Colfax Gulch rejoins North Dry Gulch at the

intersection of Pierce Street and Colfax Avenue. Between

Balsam and Pierce Streets, the North Dry Gulch flow is

significantly reduced by the amount of the flow carried

by Colfax Gulch.