APPLICATION OF A LEAKAGE MODEL TO ASSESS EXFILTRATION FROM SEWERS

The hydrological approach was originally developed to simulate the interaction between the groundwater and surface water, it was adapted to allow for modelling of interactions between groundwater and sewer system. The hydrodynamic runoff model HYSTEM EXTRAN was used. In order to approximate the exfiltration specific model parameters infiltration specific parameters were used as a basis. Scenario analysis of the exfiltration in a city from 1997 to 1999 shows the variation and the extend of exfiltration rates.