FLOOD02983

• County: Arapahoe
• Community: Littleton
• Stream Name: Lee Gulch, Little Creek
• Basin: South Platte
• Title: Major Drainageway Planning
• Date: 9/1/1978
• Prepared For: Littleton
• Prepared By: UDFCD
• Contract/PO #: &&
• Floodplain - Doc Type: Floodplain Report/Masterplan

4, PROPOSED OPEN CHANNEL WI
ST. CROSS I NGS IMPROVED 3)

4~ OPEN CHANNEL. 5 YEAR
DESIGN FREQUENCY
6. DETENTION FACILITY

5, ENLARGE 8ROADWAY CROSSING
5. HIGHLINE CANAL FLOW SEP-
ARATION STRUCTURE
6. HI GHL I NE CANAL TO 3. 5 YEAR REL I EF STORM DRA IN
DRAINAGE DIVIDE TOTAL
1) ALL ALTERNATES REQUIRE ZONING AND REGULATION
BEFORE AND AFTER IMPROVEMENTS.

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REACH

No,1

LOCATION

LEE GULCH
1. SO. PLATTE RIVER TO
ELATI STREET

LEE GULCH LITTLE CREEK
ALTERNATE REACH REACH
NO. DESCRIPTION 1 2 3 1 2 3 4 5 6
1 . FLOOD PLAIN ZONING OF IZZZl IZZZl IZZZI IZZZI IZZZI IZZZI IZZZJ IZZZI lZZZJ
EXISTING FLOOD PLAIN
2. NATURAL WATERWAY IZZZ]
3. CLOSED CONDU IT (BOX OR IZZZl IZZZI = =
PIPE SECTION)
4. OPEN CHANNEL
A) GRASS LINED, 4:1 IZZZl
SIDE SLOPES
B) GRASS LI NED, EUROPE- =
AN
C) RIP RAP LI NED IZZZl 1ZZZ:J
5. SELECT ED STRUCTURAL JZZZJ IZZZ1 IZZZZl =
IMPROVEMENTS
6. DETENTION FACILITY IUD
7. ACQU I S IT I ON OF FLOOD =
PRONE PROPERTY
8. NON STRUCTURAL METHODS IZZ7J lZZZl = = IZZZJ = = =
9. RELOCATE CHANNEL TO
OTHER THAN HISTORIC
CHANNEL

2. ELATI STREET TO LITTLE-
TON CITY L I M ITS

3. L I TT LETON C I TV LI M I TS
TO ARAPAHOE COUNTY LINE

LI TTLE CREEK 1)

L SOUTH PLATTE RIVER TO
LAKE STREET
2. LAKE STREET TO CALEY ST.

3~ CALEY STREET TO GALLUP
STREET

3B. GALLUP STREET TO ELATI
STREET

4. ELATI STREET TO
8ROADWAY

5. BROADWAY TO HIGHLINE
CANAL

ALTERNATE

..... ,-,""'" BENEFIT
IMr-ROVE,V1LI"
COST
COST RATIO

AVERAGE
ANNUAL
COST TO
SOCIETY

13

12

9
9

3

46

128

45

12

28

61

76
76

22
448
PLAIN

2) FURTHER STUDY NECESSARY TO DETERMINE OPTIMUM LOCATION & SECTION.

3) BENEFIT COST ANALYSIS DOESN'T INCLUDE COST OF STREET IMPROVEMENTS OR FLOOD
DAMAGE TO PROPOSED STREET AND CROSSINGS.

azm ALTERNATE SELECTED FOR EVAWATION

FIGURE ]I

MAJOR DRAINAGEWAY PLANNING

LEE GULCH-LITTLE CREE.K
URBAN DRAINAGE AND FLOOD CONTROL DISTRICT
CITY OF LITTLETON ARAPAHOE COUNTY

ALTERNATE 8 SCREENING MATRIX

K'K'B.N'A Inc" consultif19 Enginee"
7456 W. 5th Ave. Denver,Colorado

No.1

D ESCR'IPTION

ALL COSTS IN THOUSANDS OF DOLLARS

1, FLOOD PLAI N ZON I NG OF
EXISTING FLOOD PLAIN
5. EROSION PROTECTION AT
WINDERMERE ST.&ABAND.
1. FLOOD PLAIN ZONING OF
EXISTING FLOOD PLAIN
5, EROSION PROTECTION AT
BROADWAY
5. S I DE CHANNEL SP I LLWAY ON
HIGHLINE CANAL
1. FLOOD PLAIN ZONING OF
EXISTING FLOOD PLAIN
TOTAL

17

2.0

DAM

28

1.0

48

93

3, CLOSED CONDUIT 100 YEAR
DES I GN FREQUENCY 2)

4c, OPEN CHANNEL, 5 YEAR
DESIGN FREQUENCY

2. NATURAl WATERWAY

1,762

6.2

293

3.2

151

1.4

26

0.4

454

1.3

277
102
291

1.5
5.1
2.5

184
3,540
OF THE 100 YEAR

1.4

FLOOD

TABLE m

MAJOR DRAINAGEWAY PLANNING
LEE GU LCH - LITTLE CRE E.K
U'lBAN DRAINAGE AND FLOOD CONTROL DISTRICT
CITY OF LITTLETON ARAPAHOE COUNTY

RECOMMENDED ALTERNATES

KK'BN'A Inc" Consulting Engineers
7456 W. 5th Ave, Denver. Colorado !

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