FLOOD00268

• County: Jefferson
• County: Denver
• Community: Lakewood, Denver
• Stream Name: Dry Gulch
• Title: Flood Hazard Area Delineation - Dry Gulch and Tributaries
• Date: 11/1/1977
• Prepared For: Denver / Lakewood
• Prepared By: UDFCD
• Floodplain - Doc Type: Floodplain Report/Masterplan

I

I

I

I

I

Hydrologic
Point

DRY GULCH

I

D-O
D-l
D-2.2
D-3
D-4

I

I

D-5
D-7
D-7.l
D-8
D-lO
D-11
D-12
D-15
D-16.2
D-17
D-18.2

I

I

I

I

I

Trib. Area
Sq. 14i.

0.274

0.106
0.082

0.163

0.240

0.546
0.167

0.261
0.445
0.603
0.775
3.295
3.482
3.738

Length
L, Mi.

0.85
0.63
0.48
0.83
1.01

1.72
0.99

1.01
1.60
2.18
2.78
4.52

5.93

TABULATION

Dist. to
Centroid. Hi.

0.37

0.32
0.21

0.40

0.57

0.85
0.51

0.45
0.76
1.09
1. 37
2.28

3.17

NORTH DRY GULCH AND COLFAX GULCH

I

N-l
N-2
N-5
N-6
N-7
N-8
N-I0

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I

I

I

I

0.459
0.557
0.675
0.906
0.169
0.987
1. 090

1. 34
1.62
2.15
2.67
1. 29
2.83
3.26

0.70
0.90
1. 34
1.47
0.71
1.53
1.72

% Imp.
Area, Ia.

39

60
60

70

78

63
56

63
65
62
60
57

55

44
44
47
49
64
52
52

Ct

0.49

0.32

0.34

0.29

0.27

0.32
0.36

0.33
0.32
0.33
0.34
0.35

0.36

0.45
0.43
0.41
0.40
0.32
0.38
0.38

C
P

0.55

0.49
0.51

0.48

0.46

0.50
0.52

0.50
0.49
0.50
0.51
0.50

0.51

0.53
0.56
0.55
0.54
0.49
0.53

0.53

Descriptive PEAK DISCHARGES, CFS
Note 10-yr 100-yr

233

a

143
130
213
521

c

d

526

e

817
167
844
961
1010
1015
961
1546
1556
1477

f

g

h

i

:i

k

k

1

405
459
418
610
156
748
748

I,m

Ln

Lo

[l

q

336
197
178
292
727

707
1185
234
1237
1392
1441
1493
1419
2238
2232
2146

574
654
558
902
218
1090
1090

8

DESCRIPTIVE

NOTES

a. Most of D-l flow leaves basin to south in proposed storm sewer,
or flows east on Colfax.

L Actual flows at D-2 Clre increased by flows from D-l.

". Parameters include D-2.2 and D-3.

d. Computed by combining hydro graphs from D-l, 0-4, D-3, (assuming
ponding as in present condition), and D-O (neglecting ponding and
allowing direct runoff to D-5) .

e. Parameters include D-4, D-6, D-7. Flow is computed by combining
the hydrographs from D-O, D-l, 0-3.

f. Computed by calculating hydrograph crossing Colfax from D-7 (via
rating curve) and combining with CUHP from D-7.l.

g. Flow is from combination of hydrograph from D-8 and CUHP at 0-10.

h. Parameters include D-lO and D-ll. Flow is peak of combined hydro-
graphs from D-8 and D-ll.

i. Parameters include D-lO, D-ll, and D-12. Flow is peak of combined
hydrographs from D-8 and D-12.

j. Parameters include D-lO, D-ll, D-12, D-13, and D-15. Flow is
peak of combined hydrographs from D-8 and D-15.

k. Parameters include all areas of Dry Gulch and North Dry Gulch.
Flow is peak of the single hydrograph computed using these para-
meters.

1. Flow is peak obtained by combining the CUHP with the hydrograph
of flow out of Dry Gulch Channel at D-7 (Garrison and COlfax).
The hydrograph from D-7 is routed by the Muskingum Method.

ID. Parameters include N-l and N-2.

n. Parameters include N-l, N-2, and N-S. These flows are split be-
tween North Dry and Colfax Gulches.

o. Parameters include N-l, N-2, N-5 and N-6. These flows are split
between North Dry and Colfax Gulches.

p. Parameters include N-l, N-2, N-5, N-6, and N-8, but exclude N-7.
Flow is the peak obtained by combining the CUHP with the CUHP
from N-7 and the routed hydrograph from D-7.

q. Parameters include N-l, N-2, N-5, N-6, N-8, and N-IO, but exclude
N-7. Flow is the peak obtained by combining the CUHP with the
routed hydrographs from N-7 and D-7.

TABLE 2
TABULATION OF BASIN HYDROLOG IC
PARAMETERS AND PEAK DISCHARGES
URBAN DRAINAGE AND FLOOD CONTROL DISTRICT
FLOOD HAZARD AREA DELINEATION
DRY GULCH AND TRIBUTARIES