Porous surfaces have been used all over the world as a source control technique on car parks to minimize flooding problems. Several studies pointed out the reduction of the infiltration capacity of porous mixtures surfaces after several years of use. Therefore, it is necessary to design and develop a new methodology to quantify this reduction and to identify the hypothetical differences of permeability between zones within the same car park bay due to the influence of the static loads of the vehicles parked. With this aim, nine different zones were selected in order to check this hypothesis (four points under the wheels of a standard vehicle and 5 points between wheels). This article presents the results of the reduction of the infiltration capacity of Polymer Modified Porous Concrete (9 bays) and Porous Asphalt (9 bays) surfaces in the University of Cantabria Campus parking area (Spain) after 5 years since their construction by using the LCS permeameter. Statistical analyses methodology was proposed to analyze the results. Significant differences were observed on permeability and reduction of the infiltration capacity in the case of porous concrete surfaces while no differences were showed by porous asphalt depending on the measurement zone.