The flow detention box is complemented with the design of open detention facilities (e.g. dry ponds, ditches or swales), infiltration and percolation basins.

User inputs are e.g. pore shares (e.g.macadam or structural soil), exfiltration rates (mm/h) to surrounding ground, facility length, width and depth.

Results are e.g. designed volume (compared to required flow detenton volume) and exfilration outflow (l/s) through bottom and/or sides.