Support

Questions, a result that looks wrong, or a method you would like added: write to us.

Contact

Email support@syncster.dev. For a result you doubt, please include the method, the unit system and the inputs, or attach the PDF report.

Common questions

Which time of concentration method should I use?

Each was derived for a kind of catchment, which the note under the result names: Kerby and the FAA equation for overland flow, Kirpich for small catchments with channels, the NRCS lag equation for rural catchments, Bransby Williams for larger ones. Where two apply, compare them.

Where do the runoff coefficient and the curve number come from?

From tables for the land cover and soil of your catchment, in your local drainage standard or a hydrology reference. The app does not choose them for you.

Where do I get the IDF coefficients?

From the rainfall agency or drainage manual for your location and return period, fitted to the form i = a / (t + b)^c with the duration in minutes.

Why is the detention storage called a first estimate?

It is the volume between two triangular hydrographs. A basin is sized by routing the inflow through its storage and outlet, which this estimate is the starting point for.

Where are my saved calculations?

Under the Saved tab, on the device only. Deleting the app deletes them.