FLOOD10385

• County: Jefferson
• Community: Golden, Lakewood
• Stream Name: Upper Lena Gulch
• Basin: South Platte
• Title: Major Drainageway Planning - Upper Lena Gulch - Phase B Report
• Date: 3/1/1994
• Prepared For: UDFCD
• Prepared By: Boyle Engineering Corporation
• Floodplain - Doc Type: Floodplain Report/Masterplan

TABLE 8
SUMMARY OF PHASE A BENEFIT - COST ANALYSIS
UPPER LENA GULCH
(Continued)

TABLE 8

SUMMARY OF PHASE A BENEFIT - COST ANALYSIS

UPPER LENA GULCH

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Reach Reach Description Alternative B/C Ratio
Lll Outlet under gas station drive way to Zeta Street 1. Do Nothing N/A
culvert outlet 2. 100-yr. channel .02
3. Erosion protection .06
L12 Outlet of Zeta St. culvert to confluence with Apex 1. Do Nothing N/A
Gulch 2. 10-yr. channel .12
3. 100-yr. channel .06
4. Erosion protection .39
L13 Confluence with Apex Gulch to end of study area 1. Do Nothing N/A
2. Erosion protection .06
3. lO-yr. culverts .04
4. 100-yr. culverts .06
Pleasant View Tributary
P-l&2 Confluence with Lena to beginning of improved 1. Do Nothing N/A
channel
P-3 Beginning of improved channel to end of study area 1. Do Nothing N/A
2. lO-yr. channel 2.35
3, 100-yr. channel 1.80
Apex Gulch
AG Apex Gulch from confluence to end of study area I. Do Nothing N/A
2. Erosion protection .15
3. lO-yr. culvert upper road .51
4. 100-yr. culvert upper road .49
5. 100-yr. culvert Hwy 93 .05

and Orion St.

Orchard St.

Oth Ave.

at S. Golden Rd

Includes culverts

**

B/C Ratio
N/A
N/A
N/A
3.27
2.57
.34
.79
N/A
.49
N/A
.00
.36
.33
N/A
.17
2.92
2.09
N/A
.24
.32
.19
1.67
.94
3.74
1.87
.95
.52
N/A
.39
.53
N/A
.49
.17
N/A

Alternative
1. Do Nothing
2. Selected toe protection
1. Do Nothing
2. lO-yr. culvert Y oungfield
3. 100-yr. culvert Youngfield
4. Limited Structural
5. Remove Structures
1. Do Nothing
2. Upper Detention Pond
1. Do Nothing
2. Enlarge Welch Ditch Crossing
4. 10-yr. Channel
4. 100-yr. Channel
1. Do Nothing
2. Erosion Protection
3. 10-yr. Channel
4. 100-yr, Channel
1. Do Nothing
2. 100-yr. culvert S. Golden Rd.-
3. 10-yr. culvert lOth Ave.
4. 100-yr. culvert 10th Ave.
5. lO-yr. culvert Orchard St.
6. 100-yr. culvert Orchard St.
7. 10-yr. culvert. Orion St.
8. 100-yr. culvert Orion St.
9. lO-yr. channel **
10. 100-yr channel **
I. Do Nothing
2. Jeffco Openspace detention pond
3. Jeffco and Denwest ponds
1. Do Nothing
2. lO-yr. Channel
3. 100-yr. Channel
1. Do Nothing

West Pond #4

to South Golden Rd.

South Golden Rd. to inlet of Orion St.

West to Confluence with Pleasant

Culvert

Reach Description
Maple Grove Res. to Y oungfield St.

Y oungfield Street to Outlet to Denver

Denver

Confluence with Pleasant View

West Office Park

Upper Denver
View

Reach
Ll

L2

L4

L3

L5

L6

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to D/S end of trailer park on

Upstream of Orion St.
Vernon Rd.

L7

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D/S end of trailer park to outlet of 6th Ave.
culvert

L8

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N/A
.17
.09
.41

Do Nothing
lO-yr. channel
100-yr. channel
Erosion protection

1.
2.
3
4

end of

of

to outlet

Outlet of 6th Ave. culvert to upstream
concrete channel
Upstream end of concrete channel
culvert under gas station driveway

L9

L10

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29

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