July 25, 2024 Conservation Commission Meeting (linked)
agenda center agenda
| Board/Commission | Conservation Commission |
|---|---|
| Meeting Date | July 25, 2024 |
| Pages | 7 |
| File Size | 0.2 MB |
| OCR Status | Searchable (OCR processed) |
| Source URL | Original |
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Hydraulic Analysis Report Project Data Project Title: Swale Analysis for Roberts Village Drive Project Date: July 17, 2024 Project Units: U.S. Customary Units *Analysis for all channels is based on the 100‐yr storm event Channel Analysis: Swale 1A Notes: Input Parameters Channel Type: Trapezoidal Side Slope 1 (Z1): 2.0000 ft/ft Side Slope 2 (Z2): 2.0000 ft/ft Channel Width 3.00 ft Longitudinal Slope: 0.0200 ft/ft Manning's n: 0.0434 Flow 8.3090 cfs Result Parameters Depth 0.6536 ft Area of Flow 2.8151 ft^2 Wetted Perimeter 5.9229 ft Hydraulic Radius 0.4753 ft Average Velocity 2.9516 ft/s Top Width 5.6143 ft Froude Number: 0.7346 Critical Depth 0.5454 ft Critical Velocity 3.7240 ft/s Critical Slope: 0.0387 ft/ft Critical Top Width 5.18 ft Calculated Max Shear Stress 0.8157 lb/ft^2 Calculated Avg Shear Stress 0.5932 lb/ft^2 Channel Lining Analysis: Swale 1A Notes: Lining Input Parameters Channel Lining Type: Vegetation Specific Weight of Water: 62.4 lb/ft^3 Height of Vegetation: 0.333 ft Vegetation Condition is good Growth Form of Vegetation is mixed Cf: 0.75 See HEC-15, Table 4.5 (default: 0.75 for Good cover factor and Mixed growth form) soil is noncohesive D75: 2 mm Safety Factor: 1 Lining Results Cn: 0.165205 Permissible Soil Shear Stress: 0.031496 lb/ft^2 Mean Boundary Shear Stress: 0.593162 lb/ft^2 Maximum Shear Stress on the Channel Bottom: 0.815676 lb/ft^2 Manning's n: 0.0433644 Soil Grain Roughness: 0.0170218 Effective Shear Stress: 0.0277607 lb/ft^2 Permissible Shear Stress on Vegetation: 0.817655 lb/ft^2 This value is compared with the maximum shear stress times the safety factor to determine lining stability This value is compared with the maximum shear stress times the safety factor to determine lining stability Channel bottom is stable Channel Lining Stability Results 2 The channel is stable Channel Summary Name of Selected Channel: Swale 1A Channel Analysis: Swale 1B Notes: Input Parameters Channel Type: Trapezoidal Side Slope 1 (Z1): 2.0000 ft/ft Side Slope 2 (Z2): 2.0000 ft/ft Channel Width 3.00 ft Longitudinal Slope: 0.0530 ft/ft Manning's n: 0.0420 Flow 2.1400 cfs Result Parameters Depth 0.2263 ft Area of Flow 0.7814 ft^2 Wetted Perimeter 4.0121 ft Hydraulic Radius 0.1948 ft Average Velocity 2.7387 ft/s Top Width 3.9053 ft Froude Number: 1.0790 Critical Depth 0.2375 ft Critical Velocity 2.5935 ft/s Critical Slope: 0.0449 ft/ft Critical Top Width 3.95 ft Calculated Max Shear Stress 0.7485 lb/ft^2 Calculated Avg Shear Stress 0.6441 lb/ft^2 Channel Lining Analysis: Swale 1B Notes: Lining Input Parameters Channel Lining Type: Vegetation Specific Weight of Water: 62.4 lb/ft^3 Height of Vegetation: 0.333 ft Vegetation Condition is good Growth Form of Vegetation is mixed Cf: 0.75 See HEC-15, Table 4.5 (default: 0.75 for Good cover factor and Mixed growth form) soil is noncohesive D75: 2 mm Safety Factor: 1 Lining Results Cn: 0.165205 Permissible Soil Shear Stress: 0.031496 lb/ft^2 Mean Boundary Shear Stress: 0.644102 lb/ft^2 Maximum Shear Stress on the Channel Bottom: 0.748476 lb/ft^2 Manning's n: 0.0419586 Soil Grain Roughness: 0.0170218 Effective Shear Stress: 0.0272092 lb/ft^2 Permissible Shear Stress on Vegetation: 0.765501 lb/ft^2 This value is compared with the maximum shear stress times the safety factor to determine lining stability This value is compared with the maximum shear stress times the safety factor to determine lining stability Channel bottom is stable Channel Lining Stability Results 2 The channel is stable Channel Summary Name of Selected Channel: Swale 1B Channel Analysis: Swale 1C Notes: Input Parameters Channel Type: Trapezoidal Side Slope 1 (Z1): 2.0000 ft/ft Side Slope 2 (Z2): 2.0000 ft/ft Channel Width 3.00 ft Longitudinal Slope: 0.0410 ft/ft Manning's n: 0.0468 Flow 1.6440 cfs Result Parameters Depth 0.2227 ft Area of Flow 0.7674 ft^2 Wetted Perimeter 3.9961 ft Hydraulic Radius 0.1920 ft Average Velocity 2.1422 ft/s Top Width 3.8909 ft Froude Number: 0.8501 Critical Depth 0.2009 ft Critical Velocity 2.4053 ft/s Critical Slope: 0.0584 ft/ft Critical Top Width 3.80 ft Calculated Max Shear Stress 0.5698 lb/ft^2 Calculated Avg Shear Stress 0.4913 lb/ft^2 Channel Lining Analysis: Swale 1C Notes: Lining Input Parameters Channel Lining Type: Vegetation Specific Weight of Water: 62.4 lb/ft^3 Height of Vegetation: 0.333 ft Vegetation Condition is good Growth Form of Vegetation is mixed Cf: 0.75 See HEC-15, Table 4.5 (default: 0.75 for Good cover factor and Mixed growth form) soil is noncohesive D75: 2 mm Safety Factor: 1 Lining Results Cn: 0.165205 Permissible Soil Shear Stress: 0.031496 lb/ft^2 Mean Boundary Shear Stress: 0.491321 lb/ft^2 Maximum Shear Stress on the Channel Bottom: 0.56984 lb/ft^2 Manning's n: 0.0467581 Soil Grain Roughness: 0.0170218 Effective Shear Stress: 0.0166809 lb/ft^2 Permissible Shear Stress on Vegetation: 0.950641 lb/ft^2 This value is compared with the maximum shear stress times the safety factor to determine lining stability This value is compared with the maximum shear stress times the safety factor to determine lining stability Channel bottom is stable Channel Lining Stability Results 2 The channel is stable Channel Summary Name of Selected Channel: Swale 1C