Froude Number Calculator Froude Number Calculator Calculate the Froude Number for any channel using: \[ \mathrm{Fr} = \frac{V}{\sqrt{g\,d}} \] * Enter the flow velocity \(V\) (ft/s) and the hydraulic depth \(d\) (ft). Step 1: Enter Parameters Flow Velocity, \(V\) (ft/s): Example: 5 ft/s Hydraulic Depth, \(d\) (ft): Example: 2 ft Calculate Froude Number Calculated Froude […]
Read MoreAverage Velocity Calculator for Shallow Concentrated Flow Average Velocity Calculator Calculate the average velocity for shallow concentrated flow using Manning’s Equation: \[ V = \frac{1}{n} R^{\frac{2}{3}} S^{\frac{1}{2}} \] * Enter Manning’s roughness coefficient \(n\), hydraulic radius \(R\) (ft), and slope \(S\) (ft/ft). Step 1: Enter Parameters Manning’s Roughness Coefficient, \( n \): Example: 0.015 Hydraulic […]
Read MoreKirpich’s Time of Concentration Calculator Kirpich’s Time of Concentration Calculator Calculate the time of concentration using Kirpich’s Equation: \[ T_c = \frac{0.0078\, L^{0.77}}{S^{0.385}} \] * Enter the watercourse length \(L\) (ft) and the slope \(S\) (ft/ft). Step 1: Enter Parameters Watercourse Length, \( L \) (ft): Example: 1000 ft Slope, \( S \) (ft/ft): Example: […]
Read MorePeak Discharge (Qp) Calculator by Tabular Hydrograph Method Peak Discharge (Qp) Calculator Calculate the peak discharge using the Tabular Hydrograph Method (triangular hydrograph approximation): \[ Q_p = \frac{2V}{T \times 60} \] * Enter the total runoff volume \(V\) (ft3) and the runoff duration \(T\) (minutes). Step 1: Enter Parameters Total Runoff Volume, \( V \) […]
Read MoreKirpich’s Time of Concentration Calculator Kirpich’s Time of Concentration Calculator Calculate the time of concentration using Kirpich’s Equation: \[ T_c = \frac{0.0078\, L^{0.77}}{S^{0.385}} \] * Enter the watercourse length \(L\) (ft) and the slope \(S\) (ft/ft). Step 1: Enter Parameters Watercourse Length, \( L \) (ft): Example: 1000 ft Slope, \( S \) (ft/ft): Example: […]
Read MoreKerby’s Time of Concentration Calculator Kerby’s Time of Concentration Calculator Calculate the time of concentration using Kerby’s Equation: \[ T_c = \frac{0.00045\, L^{0.85}}{\sqrt{S}} \] * Enter the watercourse length \( L \) (ft) and the slope \( S \) (ft/ft). Step 1: Enter Parameters Watercourse Length, \( L \) (ft): Example: 1000 ft Slope, \( […]
Read MoreFAA Time of Concentration Calculator FAA Time of Concentration Calculator Calculate the time of concentration using the FAA formula: \[ T_c = \frac{L}{190\sqrt{S}} \] * Enter the watercourse length \( L \) (ft) and the slope \( S \) (ft/ft). Step 1: Enter Parameters Watercourse Length, \( L \) (ft): Example: 1000 ft Slope, \( […]
Read MoreStormwater Runoff Volume Calculator Stormwater Runoff Volume Calculator Calculate the total runoff volume using the NRCS (SCS) method. First, determine the runoff depth using: \[ S = \frac{25400}{CN} – 254 \quad \text{and} \quad Q = \begin{cases} 0, & P \le 0.2S \\ \frac{(P-0.2S)^2}{P+0.8S}, & P > 0.2S \end{cases} \] Then, convert runoff depth (mm) to […]
Read MoreDetention Storage Volume Calculator Detention Storage Volume Calculator Calculate the detention storage volume using the Rational Method Hydrograph: \[ Q = C \times I \times A \quad \text{and} \quad V = \frac{Q \times t}{2} \] (with \( t \) in seconds) * Enter the runoff coefficient (C), rainfall intensity (in/hr), drainage area (acres), and rainfall […]
Read MoreRational Formula Runoff Depth Calculator Rational Formula Runoff Depth Calculator Calculate the runoff depth using the formula: \[ D = C \times I \times t \] * Enter the runoff coefficient (0–1), rainfall intensity (mm/hr), and duration (hr). Step 1: Enter Parameters Runoff Coefficient, \( C \): Example: 0.5 Rainfall Intensity, \( I \) (mm/hr): […]
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