FREE DOWNLOAD!  Use this Excel spreadsheet to calculate the travel time for overland sheet flow of storm water runoff, for known values of watershed slope, flow path length, Manning roughness, and 2 yr-24 hr rainfall amount.  Calculations can be made in either U.S. or  S.I. units.

This Excel spreadsheet package includes the U.S. versions of the following five storm sewer calculations spreadsheets, which are described below:  1) Storm Sewer Hydraulic Design,  2) Rational Method-Stormwater Runoff,  3) Stormwater Inlet Size or Capacity Calcn,  4)   Hydraulic Grade Line and Energy Grade Line Calculations, and 5) Partially Full Pipe Flow Calculations

This Excel spreadsheet package includes the S.I. versions of the following five storm sewer calculations spreadsheets, which are described below:  1) Storm Sewer Hydraulic Design,  2) Rational Method-Stormwater Runoff,  3) Stormwater Inlet Size or Capacity Calcn,  4)   Hydraulic Grade Line and Energy Grade Line Calculations, and 5) Partially Full Pipe Flow Calculations

This Excel spreadsheet bundle includes the U.S. versions of the following five stormwater detention pond calculations spreadsheets, which are described below:  1) Detention Pond Routing Spreadsheets,  2) Design Storm Hyetograph Generation,  3) Rational Method - Stormwater Runoff,  4) Unit Hydrograph Calculations, 5) Direct Runoff Hydrograph Generation, and 6) Stormwater Detention Pond Calculations.

This Excel spreadsheet bundle includes the S.I. versions of the following five stormwater detention pond calculations spreadsheets, which are described below:  1) Detention Pond Routing Spreadsheets,  2) Design Storm Hyetograph Generation,  3) Rational Method Stormwater Runoff,  4) Unit Hydrograph Calculations, 5) Direct Runoff Hydrograph Generation,  and 6) Stormwater Detention Pond Calculations.

This spreadsheet bundle includes the U.S. versions of all the spreadsheets in the Storm Water Calculations category, that is all of the spreadsheets listed in the Storm Sewer Calculations Package, all of the spreadsheets listed in the Stormwater Detention Pond Calculations Bundle, and the Culvert Design spreadsheet.

This spreadsheet bundle includes the S.I. versions of all the spreadsheets in the Storm Water Calculations category, that is all of the spreadsheets listed in the Storm Sewer Calculations Package, all of the spreadsheets listed in the Stormwater Detention Pond Calculations Bundle, and the Culvert Design spreadsheet.

 These Excel spreadsheets carry out stormwater runoff routing calculations for a detention or retention pond.  An outflow hydrograph is calculated using a given inflow hydrograph, stage-storage information, and outflow control information for the following outflow control options: i) rectangular weir, ii) orifice, iii) pipe outlet control, and two stage outlet flow control with an orifice and weir or pipe and weir.  A plot showing the inflow and outflow hydrograph is provided.  A stage-storage table can be generated based on specified pond bottom area and side slope.  A composite inflow hydrograph can be generated from up to five separate inflow hydrographs.  These calculations use U.S. units.

These Excel spreadsheets carry out stormwater runoff routing calculations for a detention or retention pond.  An outflow hydrograph is calculated using a given inflow hydrograph, stage-storage information, and outflow control information for the following outflow control options: i) rectangular weir, ii) orifice, iii) pipe outlet control, and two stage outlet flow control with an orifice and weir or pipe and weir.  A plot showing the inflow and outflow hydrograph is provided.  A stage-storage table can be generated based on specified pond bottom area and side slope.  A composite inflow hydrograph can be generated from up to five separate inflow hydrographs.  These calculations use S.I. units.

These Excel Spreadsheets will generate design storm hyetographs based on input values for design recurrence interval, design storm duration, and a set of values for storm intensity vs duration for the design recurrence interval and location.  The spreadsheet will generate a Chicago Storm Hyetograph, a triangular hyetograph, a hyetograph generated by the alternating block method and a rectangular (constant intensity) hyetograph.  Calculations are in U.S. units.

These Excel Spreadsheets will generate design storm hyetographs based on input values for design recurrence interval, design storm duration, and a set of values for storm intensity vs duration for the design recurrence interval and location.  The spreadsheet will generate a Chicago Storm Hyetograph, a triangular hyetograph, a hyetograph generated by the alternating block method and a rectangular (constant intensity) hyetograph.  Calculations are in S.I. units.

 These Excel spreadsheets calculate watershed time of concentration using 6 different equations/sets of equations.  User selects the time of concentration to use based on the type of watershed.  Also calculated are rainfall intensity by the Steel equation, derivation of an equation for rainfall intensity from IDF data, and peak storm water runoff rate with the Rational Method equation. Calculations are in U.S. units.

These Excel spreadsheets calculate watershed time of concentration using 6 different equations/sets of equations.  User selects the time of concentration to use based on the type of watershed.  Also calculated are rainfall intensity by the Steel equation, derivation of an equation for rainfall intensity from IDF data, and peak storm water runoff rate with the Rational Method equation. Calculations are in S.I. units.

 Use this excel spreadsheet to carry out hydraulic design of a storm sewer line with several manholes, with an available manhole map showing the areas feeding to each manhole inlet.  The output is design storm water runoff to each inlet, pipe diameter and slope between each pair of manholes, and invert elevation at each manhole.  This spreadsheet uses U.S. units.

 Use this excel spreadsheet to carry out hydraulic design of a storm sewer line with several manholes, with an available manhole map showing the areas feeding to each manhole inlet.  The output is design storm water runoff to each inlet, pipe diameter and slope between each pair of manholes, and invert elevation at each manhole.  This spreadsheet uses S.I. units.

 These Excel spreadsheet templates can be used to generate a unit hydrograph from a storm hydrograph, to generate a storm hydrograph using storm information together with the NRCS dimensionless unit hydrograph, and to generate a design storm hydrograph from a basin unit hydrograph.  The calculations include baseflow separation by the concave method for the unit hydrograph generation.  These spreadsheets are set up for U.S. units.

 These Excel spreadsheet templates can be used to generate a unit hydrograph from a storm hydrograph, to generate a storm hydrograph using storm information together with the NRCS dimensionless unit hydrograph, and to generate a design storm hydrograph from a basin unit hydrograph.  The calculations include baseflow separation by the concave method for the unit hydrograph generation.  These spreadsheets are set up for S.I. units.

 These Excel spreadsheets will calculate the required stormwater detention pond volume using the "loss of natural storage" method, the "generalized" method, and the "rational hydrograph" method.  The outlet flow control can be designed for an orifice, a weir, or a pipe as the outlet control device.  These calculations are in U.S. units.

 These Excel spreadsheets will calculate the required stormwater detention pond volume using the "loss of natural storage" method, the "generalized" method, and the "rational hydrograph" method.  The outlet flow control can be designed for an orifice, a weir, or a pipe as the outlet control device.  These calculations are in S.I. units.

 This Excel spreadsheet workbook has 4 worksheets.  Two can be used to determine the size stormwater inlet needed for curb inlets or gutter inlets, using either an orifice model or weir model for sizing the opening. The other two worksheets can be used to calculate the capcity of either a curb inlet or a gutter inlet for specified inlet dimensions and stormwater depth at the inlet.  The calculations are in U.S. units.

  This Excel spreadsheet workbook has 4 worksheets.  Two can be used to determine the size stormwater inlet needed for curb inlets or gutter inlets, using either an orifice model or weir model for sizing the opening. The other two worksheets can be used to calculate the capcity of either a curb inlet or a gutter inlet for specified inlet dimensions and stormwater depth at the inlet.  The calculations are in S.I. units.

This Excel spreadsheet can be used for circular culvert design for either inlet control or outlet control situations.  A specified maximum headwater depth can be used along with details about the culvert material and the site to calculate the required culvert diameter.  This spreadsheet uses U.S. units.

This Excel spreadsheet can be used for circular culvert design for either inlet control or outlet control situations.  A specified maximum headwater depth can be used along with details about the culvert material and the site to calculate the required culvert diameter.  This spreadsheet uses S.I. units.

This Excel spreadsheet can be used for rectangular culvert design for either inlet or outlet control situations.  A specified maximum headwater depth can be used along with details about the culver material and the site to calculate the required culvert inside height.  This spreadsheet uses U.S. units.

This Excel spreadsheet can be used for rectangular culvert design for either inlet control or outlet control situations.  A specified maximum headwater depth can be used along with details about the culvert material and the site to calculate the required culvert inside height.  This spreadsheet uses S.I. units.

 This Excel spreadsheet calculates and plots hydraulic grade line and energy grade line for up to 10 points along a storm sewer line, based on user input of values for invert elevation, upstream pipe slope, distance from previous point, pipe diameter, Manning roughness, design stormwater flow rate, and surface elevation.  Calculations are in U.S. units

  This Excel spreadsheet calculates and plots hydraulic grade line and energy grade line for up to 10 points along a storm sewer line, based on user input of values for invert elevation, upstream pipe slope, distance from previous point, pipe diameter, Manning roughness, design stormwater flow rate, and surface elevation.  Calculations are in S.I. units

This partially full pipe flow calculator spreadsheet package contains worksheets to calculate 1) pipe flow rate, ii) normal depth, iii) required diameter for a target depth/diameter ratio, iv) required pipe slope, or v) Manning roughness coefficient, for partially full pipe flow, with calculations in U.S. units.

Partially Full Pipe Flow Calculator

This partially full pipe flow calculator spreadsheet package has been newly updated to contain worksheets to calculate i) pipe flow rate, ii) normal depth, iii) required diameter for a target depth/diameter ratio, iv) required pipe slope, or v) Manning roughness coefficient, for partially full pipe flow, with calculations in S.I. units.

This Excel spreadsheet workbook generates a direct runoff hydrograph for a design storm based on user input information about the design storm and the watershed.  There are three worksheets.  The first is for setting the CN (curve number) value for the watershed.  This can be done either as a single CN value for the watershed or as a calculated composite CN from user entered values of area and CN for up to 10 subareas in the watershed.  The second worksheet calculates the total direct runoff from the design storm using the CN value from the first worksheet and a user input value for the total rainfall depth from the design storm. Values are obtained for AMC I, AMC II, and AMC III.  The third worksheet generates the direct runoff hydrograph for the design storm, using the NRCS dimensionless unit hydrograph together with the calculated total direct runoff from the storm and user input values for watershed area and watershed time of concentration.  Calculations are in U.S. units.

This Excel spreadsheet workbook generates a direct runoff hydrograph for a design storm based on user input information about the design storm and the watershed.  There are three worksheets.  The first is for setting the CN (curve number) value for the watershed.  This can be done either as a single CN value for the watershed or as a calculated composite CN from user entered values of area and CN for up to 10 subareas in the watershed.  The second worksheet calculates the total direct runoff from the design storm using the CN value from the first worksheet and a user input value for the total rainfall depth from the design storm. Values are obtained for AMC I, AMC II, and AMC III.  The third worksheet generates the direct runoff hydrograph for the design storm, using the NRCS dimensionless unit hydrograph together with the calculated total direct runoff from the storm and user input values for watershed area and watershed time of concentration.  Calculations are in U.S. units.