Equation Quick ListFlow ThroughSuggested Equation(Ac-Ft)*(0.01676)=CFSor(Ac-Ft)*(7.54)=GPMWhen to use:Flow through can only be permitted using the SW-1 and SW-2 forms and are used to supply off channel reservoirs with the use of fish with oxygenated water.How to use:You will need the capacity of the reservoir in acre-feet.On Channel Reservoir CapacitySuggested Equation(Area*Depth)/3=CapacityWhen to use:Use this formula to calculate the capacity of a reservoir located in the channel of a water way when filing an SW-3 or SW-4.How to use:Calculate the area of the reservoir in acresUse the maximum depth of water in feetThe results will be in acre-feetPit Reservoir Capacity FormulaSuggested Equation((D/6)(area of top + area of bottom + 4* average area))/43560=Capacity in acre-feetWhen to use:Use this formula when applying for a reservoir on either SW-3 or SW-4 form and no water is to be stored above ground or against a berm.How to use:D is the maximum depth of the pitArea of the top for a rectangular reservoir is length multiplied by the widthArea of bottom for a rectangular reservoir is the length multiplied by the widthAverage area is the area of the top plus the area of the bottom divided by 2Pump FormulaSuggested EquationQ=HP(3960E)/T.D.H.When to use: When using a pump to apply water to lands using an SW-1 or SW-2 application not covered under Special Applications filings rules. If the filing falls in the category of Special Application the maximum amount of water that can be diverted is 0.056 Cubic Feet Per Second.How to use:HP is the horsepower of the pump which is typically found on the pumpT.D.H. is the total dynamic head (Total dynamic head includes the friction in the pipe as well as the lift it has to make. The friction in the pipe will vary by type of pipe used.)E is the efficiency of the pumpQ is the discharge flow rateFlow Rate DitchesSuggested Equation ManningsQ=(1.486AR^0.667S^.5)/nWhen to use:Use this formula for open channel earthen ditches filed for on an SW-1 or SW-2 formHow to use:Q is the discharge flow rateA is the area of the channelR is the hydraulic radius, which is the area divided by the wetted perimeterS is the slopen is the Manning’s numberGravity Flow PipelineSuggested Equations either Hazen-Williams or WeirsHazen-WilliamsQ=VAQ=A*(1.318*C)*(R^063)*(S^0.54)WeirsQ=CLH^(3/2)When to use:Use either of these equations for filing SW-1 or SW-2 forms for gravity and pressure flow pipelinesHow to use:Q is the discharge flow rateV is the velocityA is the AreaC is the Hazen-Williams CoefficientR is the hydraulic radiusS is the slopeC is the coefficient of dischargeL is the length of the crest in feetH is the feet of head