FLOOD00591

• County: Weld
• Community: Greeley
• Stream Name: Cache La Poudre River
• Title: Floodplain and Floodway Analysis
• Date: 2/20/1994
• Prepared For: CWCB
• Prepared By: Brown & Caldwell
• Floodplain - Doc Type: Floodplain Report/Masterplan

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3. ANALYSIS (Cont'd)

Loss Coefficients

~nlrance loss coefficient

Manning's "n" value assigned to the slruclure(s)

Friction loss coefficient through structure (s)

Other loss coefficients (e.g., bend

manhole, etc.)

Tolalloss coefficient

0.03

Weir coefficient

1.7
2.6

1. 05

Pier coefficient

Contraction loss coefficient

0.3
0.5

Expansion loss coefficient

4. SEDIMENT TRANSPORT CONSIDERATIONS

1. ^. Is there any indication from historical records that sediment transport (including 8cour and deposition) can
affect the 1 OO-year water surface elevations? 0 Yes 1Kl:'>/0

B Based on the conditions (such as geomorphology, uegetatiue couer and deuelopment of the watershed and stream
bed, and bank conditions), is there a potential for debris and sediment transport (including scour and
deposition) to affect the 1 OO-year water surface elevations and/or conveyan"e "apacity through the
bridge/culvert? .... 0 Yes Ii(]:,>/o

2. If the answer to either lA or IS is yes:
A. What is the estimated sediment (bed material! load?
cfs (attach gradation curue)

I;;xplain method used to estimate the sediment transport and the depth of scour and/or
deposition

B Will sedimen-. accumulate anywhere through the bridge/culvert?D Yes !Xl:'>lo

If yes, explain the impact on the conveyance capacity through the
br'idge/cu Ivert?

S. FlDDDWA Y ANAL YS'S

Explain method of bridge encroachment
inoodway run)

Bridge/Culvert form

form 7

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