XPRafts currently accepts either Initial and Continuing Loss Model, or infiltration parameters to suit Philip's Infiltration Module using comprehensive ARBM algorithms to simulate excess runoff.

It is difficult to recommend average loss values, as soils and vegetation vary considerably. Initial losses can vary between 0 and 150 mm and continuing losses from 0 to 25 mm/h.

Loss rates should be assessed separately for each sub-catchment. Significant improvements in loss rate estimates can be obtained by catchment inspection and soil moisture and infiltration measurements over even a limited period.