Hello, can anyone tell me how to calculate the drainage for a carport?
We want to build a carport and need to inform the authorities about the drainage.
The carport will not be connected to the sewer system!
We plan to let the water seep into a hole behind the carport, but we don’t know what factors need to be considered for this.
Does anyone happen to have any ideas?
Thanks in advance
We want to build a carport and need to inform the authorities about the drainage.
The carport will not be connected to the sewer system!
We plan to let the water seep into a hole behind the carport, but we don’t know what factors need to be considered for this.
Does anyone happen to have any ideas?
Thanks in advance
If the ground is reasonably permeable, just dig a hole—say about 50cm (20 inches) in diameter and 70cm (28 inches) deep. Place a concrete ring inside and fill it with gravel. If possible, install a drainage pipe in the upper third of the ring leading towards the main sewer or the street to handle extreme heavy rainfall.
@apokolok 207 liters per hectare should be about 2.5 liters per second for 60 square meters (sqm) if I’m not mistaken. In that case, the pipe with dimensions 50/70 mm (2/3 inches) is a bit tight. Gross volume is 0.5 cubic meters (18 cubic feet), most of which is taken up by gravel. So, not much remains available.
For approximately 250 sqm (2691 square feet) of roof area, I have a soakaway measuring 2 meters by 2 meters by 2 meters (6.6 ft by 6.6 ft by 6.6 ft), placed directly on porous sandstone, so with a quickly permeable substrate. That works fine with a standard rainfall of 280 liters per hectare (l/ha).
An emergency overflow is not a bad idea, though.
My suggestion was to have a soakaway calculated by Graf and then size your self-built soakaway based on the Graf model. That way, you have all the dimensions suited for your rainfall volume. Alternatively, you could buy the Graf unit if self-construction is not an option for some reason.
For approximately 250 sqm (2691 square feet) of roof area, I have a soakaway measuring 2 meters by 2 meters by 2 meters (6.6 ft by 6.6 ft by 6.6 ft), placed directly on porous sandstone, so with a quickly permeable substrate. That works fine with a standard rainfall of 280 liters per hectare (l/ha).
An emergency overflow is not a bad idea, though.
My suggestion was to have a soakaway calculated by Graf and then size your self-built soakaway based on the Graf model. That way, you have all the dimensions suited for your rainfall volume. Alternatively, you could buy the Graf unit if self-construction is not an option for some reason.