GSF Débit is an extension developed to calculate the dimension of culverts using the method favoured by the Quebec Minister of Natural Resources and Wildlife.

The application is presented as an easily accessible toolbar in ArcView project views. This tool consists of functions for management and configuration in addition to the main function for the calculation process.

The themes needed for this type of calculation are surficial deposits in addition to the hypsometry and the hydrology of the area. From this data and the geographical location of the culvert to set up, the user delimits the watershed and traces the principal water body (water drop) that intersects with the infrastructure.

Once the basin and water drop are determined, the user can launch the calculation from the main interface.

The "Détection" bouton give a quick access the leftlet for the 1 / 20 000 base map id.

The results of the calculations are presented in an Excel spreadsheet indicating, amongst others, the peak flow of the water body and the dimension of the structure to be set up.

The operation is rapidly carried out for simple or parallel culverts, arched pipes or other arched structures.

Moreover, all the results can be saved into the culverts, water drops and basins themes themselves.

At the 3.3.7 version of the extension, the user has the possibility to applicate a 10% majoration by using the Worksheet version 7.7. This applies only to watershed below 25 km2 (2500 ha).