FLOOD03506

• County: Jefferson
• Community: Lakewood
• Stream Name: South Lakewood Gulch
• Basin: South Platte
• Title: Major Drainageway Planning
• Date: 8/1/1978
• Prepared For: Lakewood
• Prepared By: UDFCD
• Contract/PO #: &&
• Floodplain - Doc Type: Floodplain Report/Masterplan

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SECTION I
EXECUTIVE SUMMARY

adjacent to the 100-year floodplain is recommended. Homeowners are
encouraged to obtain flood insurance.

THE STUDY AREA

3. Modifications to Rockmont College Ponds to provide an increased storm
water detention facility.

South lakewood Gulch is the drainage outfall for a 1,040 acre basin in

lakewood, Colorado. The basin originates at a point about one-half mile

south of the Denver Federal Center, and extends approximately 4 miles in a

northeasterly direction, entering the lakewood Gulch near the intersection

of West Sixth Avenue and Harlan Street. The basin is long and thin in

shape, with a length to width ratio of about 8. In some areas, the existing

gulch has been entirely contained within an underground pipe. Floodplain

encroachment is evident in the lower half of the basin. The basin is approx-

imately 70 percent developed, with mostly single family residential and some

commercial development. Sixth Avenue effectively cuts off approximately

120 acres of residential development which would otherwise be tributary to

the lower portion of the basin. Due to the fact that South lakewood Gulch

"is a rather small tributary to lakewood Gulch, there are no major sub-

tributaries other than small natural depressions and residential streets.

Because of the intense urban development, under existing conditions, much

of the local runoff is carried by the streets.

4. A grass-lined channel from the Rockmont Ponds to Cody Court.

5. A structural wall channel with a short reach of grass-lined channel

from Cody Court to First Avenue at Balsam Street with sections of

reinforced concrete box culvert at street crossings.

6. Upgrading of the pond at First Avenue for increased detention storage.

The existing channel upstream to First Avenue has a 100-year capacity

and as such will require no improvements.

7. Addition of a concrete box culvert from the pond outlet along First
Avenue daylighting in the vicinity of S. Allison Street and replacement of
a portion of the existing CMP arch pipe with concrete pipe.

MAJOR DRAINAGEWAYPlAN IMPROVEMENTS

The optimized and recommended plan for South lakewood Gulch is based on

minimizing the hazard to life and property along the channel route. The

plan utilizes grass-lined channels, structural wall channels, concrete box

cu.lverts and pipes, and storm water detention and retention ponds,as well

as floodplain regulation and del ineation. Unless otherwise noted, all

master plan improvements are designed for the 100-year event with future

basin development. The improvements include:

8. A grass-lined channel north of First Avenue from S.Allison Street to
the retaining wall upstream of Wadsworth.

9. A closed conduit from the retaining wall upstream of Wadsworth through
the auto complex.

10. Cleaning, fine grading and seeding the existing grass-lined channel
from the auto complex to Vance Street.

1. A proposed park by the City of lakewood from Kipling Street to Garrison
with a total retention facility at the Garrison property boundary.

11. The existing grass-l ined channel hom Vance Street to 6th Avenue is
adequate for the 100-year storm.

2. A grass-lined channel from Alameda to Garrison with maintenance of

existing on-stream farm ponds. Flood proofing of structures immediately

12. A grass-lined channel from downstream of Sixth Avenue to 150-feet up-

stream of Reed Street. The homeowners immediately adjacent to the 100-

year floodplain are encouraged to obtain flood insurance. Flood proofing

of these structures is recommended.

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