ᐅ Infiltration of Rainwater

Hello,

In our development area, rainwater from the roof, carport, and driveway must be infiltrated on the property. I originally planned to infiltrate the rainwater using soakaway crates located about 6 meters (20 feet) behind the house at a depth of 70-80 cm (28-31 inches). However, I am having difficulty calculating the capacity of these crates.

Overall, we have approximately 220 m² (2,370 sq ft) of drainage surface area (runoff coefficient taken into account), but I know there are other factors to consider as well. Regardless, has anyone here built a soakaway tunnel for a “typical” single-family home on relatively normal soil conditions, and if so, what size did you use?

Thanks,
Martin

We are waiting for a proposal for the rainwater infiltration system from our structural engineer; probably Graf modules will be used! The permeability coefficient values (kf-values) are also crucial. Our kf-values range between 2x10⁻⁵ and 2x10⁻⁶ m/s. It is for a single-family house with 197 m² (2,120 sq ft); I will keep you updated!

Thank you, VelBau, that would be really interesting.

Hello,

I have already mentioned this elsewhere.
Manufacturers even calculate this for you free of charge, as the values are available from the soil report.

Graf dealers usually provide free estimates. For a similar area, we calculated 7 double modules and a 1500-liter (400-gallon) flat tank as a sediment trap, costing about €1800 with piping, plus approximately €2200 for excavation, gravel, etc. And all of this just to get rid of the water again[emoji22] bg td

By the way, I think a free calculation including an infiltration report should be included for this price.