Runoff : Rational Method Formula The Runoff from a catchment is as given below; Where, Q = Runoff in cum/hr, C = Runoff coefficient, i = Intensity of rainfall in mm/hour, A = Area of drainage district in Hectares

# Pump Power

Power of Pump Formula The Pump power is as given below; Where, P = Power of Pump i kilowatt, Q = Flow in litres/second, H = Head in meters, n = Combined Efficiency of Pumpset

# Pump : Specific Speed

Specific Speed of Pump Formula The calculation for Specific Speed of Pump is as given below; Where, nq = Specific Speed of Pump, N = Operating Speed of Pump in RPM, Q = Rate of Flow in Cu.m./sec, H = Rated Head Per Stage of Pump in meter,

# Allowable Leakage

Allowable Leakage in Pipes Formula Allowable leakage during the maintenance stage of pipe carefully laid and well tested during construction is given by: Where, qL = Allowable Leakage in Cu.cm per hour, N = Number of Joints in length D = Diameter of pipe in mm, P = Average Test Pressure during leakage Test in read more

# Ground Water Flow : Pressure Well

Ground Water Flow: Pressure Well Formula The Ground water flow in pressure well in equilibrium conditions is as follows: The discharge formula in pressure well is as given below; Where, Q = Discharge in cubic meter per day, k = Permeability meter/day, m = Depth of confined aquifer in meters, H = Depth of water read more

# Maximum Surge Pressure

Max Water Hammer Pressure in Pipes Formula The calculation for maximum Water Hammer pressure is as given below; Where, Hmax = Maximum Water Hammer Pressure in meters, C = Velocity of Pressure Wave Travel in meters/sec, V = Flow Velocity in meters/sec, The Pressure Wave Velocity is as given below; Where, k = Bulk Modulus read more

# Ground Water Flow : Gravity Well

Ground Water Flow: Gravity Well Formula The flow in gravity well in equilibrium conditions is as follows: The discharge formula in Gravity well is as given below; Where, Q = Discharge in cubic meter per day, H = Depth of water in well before pumping in meters, h = Depth of water in well after read more

# Discharge : Venturi Meter

Flow in closed conduits: Venturi Meter Formula The discharge through a venturi meter is as given below; Where, Q = Discharge in cubic meter per second, a1 = Area of pipe section in Sq meters, a2 = Area of throat section in Sq meters, h = head difference between inlet and throat section K = read more

# Discharge : Drop

Open Channel Flow: Drop Formula In a drop, water falls freely from a channel to some lower level. Rough estimates of flow could be made by measuring the depth of flow at drop. The required conditions are as follows: The minimum straight upstream reach for approach channel shall be at least 20 times the end read more

# Discharge : Rectangular Notch

Open Channel Flow: Rectangular Notch The minimum width of Notches shall be at least 150 mm. Rectangular notches are generally used for measuring small flows. Formula The discharge calculation formula from Rectangular notches is as given below; Where, Q = Discharge in cubic meter per second, be = Effective Width in meters, h = Effective read more

# Discharge : V Notch

Open Channel Flow: V Notch The Notches are made from thin metal sheets. Triangular notches are generally used for measuring small flows upto about 1.25 m/s. Formula The discharge calculation formula from triangular notches is as given below; Where, Q = Discharge in cubic meter per second, Theta = Angle of Notch at center, h read more

# Pipe Headloss – Modified Hazen William

Pipe Headloss : Modified Hazen-William Formula The Modified Hazen Williams formula is derived from Darcy Weisbach formula and is as below; Where, V = Velocity of flow, Cr = Coefficient of Roughness, d = Pipe Diameter/sec, g = Acceleration due to gravity, s = Hydraulic Gradient, v = Viscosity of Fluid For circular conduits, headloss read more