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Program Downloads: Hydraulic and Hydrologic

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Program Downloads
This Hydrology by rational formula (xls 23 kb) spreadsheet calculates peak flows for small drainage areas that can be either natural or developed. It uses the rational method as described in the WSDOT Hydraulics Manual. 

Before finalizing the storm drain layout, designers should verify the layout is constructible with respect to the angle between pipes entering or exiting a junction. That is, in order to maintain the structure integrity of a junction there are minimum clearance requirements that must be met depending on the pipe diameter. Designers can verify the minimum pipe angle with the Pipe Angle Calculation Worksheet (xls 217 kb)

The Storm Sewer Pipe Sizing Spreadsheet (xls 149 kb) spreadsheet accomplishes a storm sewer design using the rational method as described in the WSDOT Hydraulics Manual.

The USGS Regression Spreadsheet (xls 235 kb) calculates runoff using the 2001 version of the USGS regression equations for Washington State. The user should have a 2004 copy of the WSDOT Hydraulics Manual or USGS Fact Sheet 016-01 to determine the input parameters. We are currently working with MIS to deploy the National Flood-Frequency (NFF) program statewide. Until then, the spreadsheets can be used.

If using the routing table, use the Dogwood Stormwater Pond spreadsheet (xls 49 kb)

An optimization routine is available, but it is not included in WHAM, the public domain version of the program. The optimization routine is available through MGS Software.

Water Quality Wet Pond Calculator (xls 19 kb)

Inlet Spacing Analysis Spreadsheets
The Inlet Spacing Spreadsheet (xls 167 kb) combines the procedures described in the WSDOT Hydraulics Manual to calculate roadway runoff and inlet interception of a continuous curb and gutter run for a roadway.

The Sag Worksheet (xls 60 kb) uses the procedure described in the WSDOT Hydraulics Manual to locate inlets in a sag condition.

The Short Duration Rainfall Depth Converter (xls 38 kb) spreadsheet converts the 2 year, 2 hour storm to the 3 hour storm for any of the four Eastern Washington Climatic Regions.

For further explanation of how to calculate the 3 hour storm, see Appendix 4D of the Highway Runoff Manual.