The urban area of the campus is drained by an extensive drainage system. The drainage system has been built to drain the shallow groundwater that accumulates on top of the marl layer at about 4-5 m depth. In spite of the original opinion that the drainage would permanently lower groundwater levels, this effect has not been observed yet. This can be due to a number of drainage ditches through which rooftop water is infiltrated. It could also have natural causes such as this area being a discharge area for a regional flow system.
The fact that the entire neighborhood is drained has a hydrological advantage. The balance of precipitation – actual evaporation can be evaluated. The percolating water that results from the climatic water balance P-ETP is drained by the drainage system and is channeled to a pond for the iron hydroxides to settle. The discharge from this pond can be measured and amounts to about 4-5 litres per second. The conversion of the discharge to a specific infiltration yields about 100 mm of groundwater recharge.
