Prefeasibility Access Road Design-Revised
26
Because no channel cross sections were evaluated, these culverts are not
guaranteed to fit within the existing channel. This should not be a concern with the
culverts in the mountainous areas as these are fill areas with lots of open space. In
the lower elevations, however, a more thorough analysis of channel cross sections
will be required during final design. Riprap will be required for most culverts and will
be evaluated during final design. Other concerns that will need to be addressed in
the final design include any corrosive soils and invert deterioration due to bed load
and high velocity flow.
Miller Creek Hydraulic Data
WS #
Required
Flow (cfs)
Number of
Culverts
Culvert Size
in.
ft
1
137
2
54
4.5
2
768
3
84
7.0
3
1122
2
120
10.0
4
136
1
72
6.0
5
300
1
90
7.5
WS
#
Culvert
Length
(ft)
Station
US
Invert
Elev.
DS
Invert
Elev.
Road
Elev.
HW
Elev.
Cover
Free-
board
1
168
191+38 5095*
5090* 5102.5 5099.5*
**
3.0*
2
124
215+68 5129.1 5128.1 5137.6 5136.1
1.8
1.5
3
285
263+31 5234.5 5230.1 5264.3 5244.5
22.3
19.8
4
610
460+02 5971.6 5929.3 6039.2 5977.6
78.2
61.6
5
296
489+09 6042.7 6025.3 6071.0 6050.2
25.0
20.8
*The culvert of watershed 1 is outside of the contour data. Therefore, the invert elevations,
headwater elevation, and the freeboard are estimated.
**There is not enough data to calculate cover.
