spreadsheet tools for quantifying the costs and … tools for quantifying the costs and benefits of...
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Spreadsheet Tools for Quantifying the Costs and Benefits of Two-Stage Channels
J. Witter, A. Ward, D. Mecklenburg, J. D’Ambrosio, S. Roley, and J. Tank
AWRA – Agricultural Hydrology and Water Quality II St. Louis, MO
March 25, 2013
Decision Aids and Design Tools
• Assessment – Reference Reach Spreadsheet
• Benefits – Instream Nitrogen Tool
• Costs – Two-Stage Ditch Cost Estimator – Two-Stage Ditch Economic Analysis
• Design – Two-Stage Cross Sections – Bank Stability and Toe Erosion Model
Powell, G.E., A.D. Ward, D.E. Mecklenburg, and A.D. Jayakaran. 2007. Two-stage channel systems: Part 1, a practical approach for sizing agricultural ditches. JSWC 62(4): 277-286.
Assessment: Reference Reach Spreadsheet
Meander Pattern - Channel Plan Form More Info
This Worksheet
1) This sheet will graph the distance and azmuth entered in the profile worksheet.2) Fill in the values below using the graphed pattern, arialphotos, topo maps, etc.3) Before printing the graph, its width or height may needadjusting. "Square" the graph by clicking and dragging.
Meander Length min maxmeander length (ft) 280 280 490
Meander Widthbelt width (ft) 135 130 150
amplitude (ft)
Bendsradius (ft) 70 40 80
arc angle (degrees) 70 30 170
Sinuositystream length (ft) 388.4
valley length (ft) 285.9
Graph FormatZ scale: 10 Dimensions (ft) Ratios
Bankfull Width: 31.0 Sinuosity: 1.4show banks Meander Length: 280 (280 - 490 ) Meander Length Ratio: 9 (9 - 15.8 )
Belt Width: 135 (130 - 150 ) Meander Width Ratio: 4.4 (4.2 - 4.8 )show centerline Radius of Curvature: 70 (40 - 80 ) Radius / BkF Width: 2.3 (1.3 - 2.6 )
Reference ReachStream: Dogskin Run
Watershed: Little MuskingumLocation:
Latitude: 39.6346Longitude: 81.0278
County: MunroeDate:
Observers:
Channel Type: C4Drainage Area (sq.mi): 2.94Pattern
typical min maxbankfull width (ft) 31.00
meander length (ft) 280.0 280.0 490.0belt width (ft) 135.0 130.0 150.0amplitude (ft) --- --- ---
radius (ft) 70.0 40.0 80.0arc angle (degrees) 70.0 30.0 170.0
stream length (ft) 388.4valley length (ft) 285.9
Sinuosity 1.4Meander Length Ratio 9.0 9.0 15.8Meander Width Ratio 4.4 4.2 4.8
Radius Ratio 2.3 1.3 2.6
Dan Mecklenburg, Dawn Farver, Andy Ward, Pam Stackler, MichelleJune 24, 2002
Marietta Unit WNF
Dogskin Run Little Muskingum Marietta Unit WNF
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250-300 -250 -200 -150 -100 -50 0 50
East West Distance
North
Sou
th D
istan
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Pattern Sheet: Meander Plan Form
Assessment: Reference Reach Spreadsheet
Two Individual
Pebble Counts
Weighted Pebble Count
Sieve Analysis for Two
Bulk Samples
Materials Sheet
Assessment: Reference Reach Spreadsheet
Dimension Sheet: Cross sectional dimension
X-section 1 X-section 2 X-section 8
Assessment: Reference Reach Spreadsheet
Cross Section 3
Bankfull Dimensions Flood Dimensions Materials83.0 x-section area (ft.sq.) 126.7 W flood prone area (ft) 39 threshold grain size (mm):49.6 width (ft) 2.6 entrenchment ratio 43 D50 Riffle (mm)1.7 mean depth (ft) --- low bank height (ft) 72 D84 Riffle (mm)2.8 max depth (ft) --- low bank height ratio51.3 wetted parimeter (ft)1.6 hyd radi (ft)29.6 width-depth ratio
Bankfull Flow Flow Resistance Forces & Power5.2 velocity (ft/s) 0.035 Manning's roughness 0.78 channel slope (%)
429.3 discharge rate (cfs) 0.12 D'Arcy-Weisbach fric. 0.79 shear stress (lb/sq.ft.)0.72 Froude number 8.1 resistance factor u/u* 0.64 shear velocity (ft/s)
7.1 relative roughness 4.2 unit strm power (lb/ft/s)
2 + 35.9 Dogskin Run, Riffle
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-40 -20 0 20 40 60 80 100 120
Width (ft)
Elev
atio
n (ft
)Assessment: Reference Reach Spreadsheet
Benefits: Instream Nitrogen Tool Results
0%10%20%30%40%50%60%70%80%90%
100%
Nitr
ogen
Dis
trib
utio
n
Trapezoidal Two-Stage
Total Export (lbs)Bed (lbs)Bench - Saturated (lbs)Bench - Unsaturated (lbs)Side Slopes (lbs)Buffer (lbs)Land Conversion (lbs)
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200
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N R
emov
ed (l
bs)
Trapezoidal Two-Stage
Bed (lbs)Bench - Saturated (lbs)Bench - Unsaturated (lbs)Side Slopes (lbs)
Buffer (lbs)Land Conversion (lbs)
Costs: Two-Stage Ditch Cost Estimator 3. Tiles Outlets and Erosion Control Measures
• Outlet Protection • Drop Structures • Sloped Outlets • Rock Chutes • Berming • Rip Rap • Instream
Structures
Regional Geometry
Cross Sections
Profile
New Channel Dimensions
Design: Two-Stage Cross Section Plots
Cross Section 3 Earthwork Balance: cut 382 sq.ft. Bench Elevation: 704.4 ft
700702704706708710712714716
-100 -50 0 50 100 150Width (ft)
Elev
atio
n (ft
)
Design: Two-Stage Cross Section Plots
Design: Bank Stability and Toe Erosion Model 5. Hydraulic Erosion
Contact Information
• Jon Witter – [email protected] – (614)292-6538
• Andy Ward – [email protected] – (614)292-9354
• Jessica D’Ambrosio – [email protected] – (614)247-7876