FLOOD03254

• County: Logan
• Community: Sterling
• Stream Name: Pioneer Ditch
• Basin: South Platte
• Title: Master Drainageway Plan Pioneer Ditch at Sterling
• Date: 12/1/1995
• Prepared For: Sterling
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Project

TABLt: ..\2
PIONEER DITCH
BRIDGE D,\'I".-\
EXISTL'IIG Al'\D DESIG~ CONDITIONS
PRIMARY L\IPROVB1ENTS

I Existing Conditions. Bridge Data I Design Conditions - Brid e Data. Future lO-Year Local Draina e Flood
Recommend Recommend Channel Bottom Side Low Low Top Pier Area belo... Channel Bottom Side Low Top of Pier Area helow Design Area below
Primary Secondary Invert Width Slopes Chord of Road Width Low Chor Invert Width Slopes Chon! Road Width Low Chord W.S. Design W.S. Velocit.\
ection Bridlte Location Imnrovemen Imnrovemen (ftnlNd) (feet) (lV:XH) (ftngvd) (ftngvd) (feet) (feet^2) (ftnlNd) (feet) (lV:XH) (ftngvd) (ftngvd) (feet) (feet^2) (ftngvd) (feet^2) (fps)
.40 Union Pacific Railroad. No No 3909.9 32.6 0.0 3917.2 3920.8 8.5 173 3909.9 32.6 0.0 3917.2 3920.8 8.5 173 3914.9 100 4.8
.50 Burlinatnn Northern Railroad No No 3911-4 17.3 0.0 3918.2 3922.9 0 103 3911.4 17.3 0.0 3918.2 3922.9 0 103 3916.0 73 6.5
.
.70 North-Bound Hi,rnwav 138 * No No 3910.4 15.0 0.0 3920.4 3921.3 0 121 3910.4 15.0 0.0 3920.4 3921.3 0 121 3917.3 78 6.1
.80 South-Bound Hiehwav 138 * No No 3911.1 20.0 0.0 3918.3 3921.4 0 131 3911.1 20.0 0.0 3918.3 3921.4 0 131 3918.2 134 3.6
1030 Sidnev Avenue ** Yes No 3914.8 10.7 0.0 924-3924. 3923.9 0 103 3914.2 10 1.0 924-3924. 3923.9 0 205 3921.9 136 3.5
1074 North 7th Avenue *** No Yes 3918.2 18.0 0.0 3928.6 3931 0 16. 3918.2 18 0.0 3928.6 3931.0 0 16. 3926.4 128 8.1
1095 Franklin Street * No No 3920.8 16.0 0.0 3930.3 3932 0 128 3920.8 16.0 0.0 3930.3 3932 0 128 3929.8 134 6.5
1105 Downstream State Highwav 1 Yes No 3828.9 13.3 0.0 3936 3937.2 0 8. 3928.2 12 2.0 3936.0 3937.2 0 215 3934.3 147 6.0
1130 State Hip'hwav 14 ^^ Ye, No 3930.3 3.1 0.0 3934.3 3941.8 0 13 3931.5 15 2.0 ++3942.3 ++ 0 420 3941.8 3.4 1.4
1145 Unstream State Hie:hwav 14 ^ Ye, No 3931.8 6.0 0.8 941-3941. 3942.2 0 167 3931.8 810 1.0 ++3942.3 ++ 0 194 3941.8 178 3.2
1155 Phelns Street ^^ Yes No 3932.6 3.2 0.0 3936.6 3943 0 13 3933.5 12 1.6 ++3942.5 ++ 0 238 3942.0 215 2.2
1180 Burlinldon N orthem Railroad No y" 3935.6 4.7 0.0 3938.6 3948.3 0 14 3935.6 4.7 0.0 3938.6 3948.3 0 14 3942.0 30 12.4

)TES:
* Represents bridges that do not require replacement or modification for design conditions.

.' Sidney Avenue Bridge is part of a channel improvement reach. The existing bridge deck is adequate, but the channel configuration under the bridge has been changed.

**, No primary improvements are recommended at North 7th Avenue because the flow is contained to the channel with tbe other channel and bridge improvements
described in the table above. If, for some reason in the future. the stages need to be lowered upstream of this bridge, the sideslopes could be flared to match the
natural channel in the vicinity of the bridge (lV:1.3H). See Table A3 for secondary modifications.

^ The bridge downstream of State Highway 14 is part of a channel improvement reach required to transition the channel realignment.
The existing bridge deck is adequate, but the channel configuration under the bridge has been changed.

^^ State Highway 14 and Phelps Street are severely undersized. Both require a new channel configuration and a new bridge deck.
The design channel configurations are trapezoidal approximations of what the natural channel looks like in tbe vicinity of the bridge.

^^^ The bridge upstream of State Highway 14 requires some minor chaunel enlargement and a new bridge deck.

+ The Burlington Northern Railroad Bridge was not recommended as a primary improvement because it is at the very upstream end of Pioneer Ditch and would not
pro\;de as much benefit as some of the other bridges downstream. Nevertheless, it is a severe restriction, and would warrant replacement sometime in the future.
See Table A3 for secondary modifications.

HAt State Highway 14, the bridge upstream of State Highway 14, and at Phelps Street, the low chord elevations are based on the calculated stage plus 0.5 foot.
This may vary according to the city's standard acceptable practices. The top of road elevations will be based on the low chord plus ~e depth of the bridge deck designed.