# WMS:Overview of Basin Data Equations

Dodson (Dodson & Associates, 1992) compiled several equations from hydrologic publications. WMS has implemented many of these equations and allows choosing from the ones listed below to automatically compute lag times/times of concentration. Because most of the equations were developed for specific watersheds (e.g. size, land cover etc.), consider the assumptions made about a given equation, and try to identify one that used watershed conditions similar to the one being studied. The following is a list of the equations available in WMS. The SCS also found that for many cases the lag time could be related to the concentration time by the following equation:

This relationship is always used by WMS to determine lag time when a method for computing time of concentration is chosen, or to compute time of concentration when a method for lag time is chosen. Methods used for lag time begin with *T _{LAG} =* whereas methods used to compute time of concentration begin with

*t*=.

_{c}### Lag Time Based Equations:

- Colorado State
- Customized
- Denver
- Eagleson
- Espey
- Putnam
- Riverside County
- SCS
- Taylor Schwartz
- Tulsa District

### Time of Concentration Based Equations:

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