Reduction of groundwater supply in areas with strong waterproofing and consequent interruption of the natural water cycle. Increases in surface temperatures due to heat island effect. Worsening of the quality of the water drained by the content of pollutants collected on impermeable surfaces, such as roofs and asphalt pavements, during intense and short-lived rains.
The need to opt for solutions designed to reduce upstream the meteoric flows circulating in the networks – be they unitary or separate – by providing, for unpolluted meteoric water, their disposal on the ground or in the surface layers of the subsoil and only in a subordinate way, in surface waterways.
The inflow coefficient is the ratio between the volume of water drained and the volume flowed to the surface and represents the percentage of inflow that leads to the leaching. The heat island is the phenomenon that determines a warmer microclimate in the more urbanized areas compared to rural areas.
The greatest heat accumulation is determined by causes such as asphalt surfaces (which prevail sharply compared to green areas), emissions from motor vehicles, industrial plants and heating and air conditioning systems for domestic use. It also includes the scarce ability to retain water from waterproof surfaces, which with a lower evaporation further reduce the cooling of the air near the ground.
Draining, pedestrian or driveway floors allow rainwater to pass through the paved surface. This water, according to current regulations, can be disposed of in two ways: directly on the surface layers of the subsoil or collected in storage tanks or Catch Basin Filter (for possible treatments, for reuse in irrigation or for fire-fighting systems) or simply conveyed to the sewer system.
The first is indicated in areas with a low contamination of rainwater and which provide for the total disposal on site of roof water and waterproofed surfaces; the second one is instead advisable for areas characterized by the presence of pollutants and where it is necessary to provide for the disposal of rainwater in the sewer system or the accumulation in special tanks.
The use of these floors is not limited to new buildings but also to cases of renovations, extraordinary maintenance or expansion, realizing these drainage systems that replace waterproof covers. They are also particularly useful in areas where it is not economically feasible to renovate sewers, and in areas that prescribe a maximum percentage of discharge of rainwater in the public collection network (for each hectare of waterproof drainage area present).
The Catch Basin Filter represents an ecological system and now tested to create large permeable areas, particularly appreciated by the urban furniture designer and the user.
