Gravel Pit

A gravel pit is an underground storage area filled with gravel. The hollows can store water, which can then slowly infiltrate into the soil. To keep the pit clean of debris, geotextile cloth is placed around it. This prevents the silting up of the pit.

With a gravel pit, you are not bound by fixed sizes or shapes. You can decide how big you make the pit. You determine the size based on how much space you have.

Cost

What you mainly need in terms of material is gravel. This material is relatively expensive. The cost is not too bad if you can get leftover lots from somewhere.

Space use

A gravel pit has a hollow space of about 30%. So the pit should be about three times larger than the amount of water to be stored. The advantage is that you can build a terrace and lawn on top of the pit, for example. This makes the space occupied by the gravel pit multifunctional.

Difficulty

Easy to construct yourself. Do consider venting and sand trap. A sand trap is a device that ensures that sand in a flowing watercourse is deposited in a controlled manner. The water is thus gradually drained away.

Earthmoving

The gravel pit should be about 25 cm underground. You can choose the thickness of the package. The content of the pit determines how much earth moving is required.

Maintenance

Keep only sand trap and leaf trap clean.

Climate Goals

Store water and provide natural replenishment of groundwater. Natural products are mainly used.

Biodiversity

Contribution to improving biodiversity

Points of interest

  • In a topsoil with a lot of clay or loam, this measure is less suitable because water does not sink quickly into the soil.
  • Allow for at least 25 cm of coverage.
  • Dig the pit to a depth of about half a meter above the average groundwater level.
  • Choose gravel pellets of about the same size.
  • Do not use a root cloth, but a geotextile cloth.
  • Situate the vent and overflow pipe in a lower part of the garden. During peak downpours, rainwater that no longer fits into the gravel pit can be collected in it.
  • Use a leaf and sand trap to prevent siltation. A leaf trap can also serve as an overflow in extreme cases.
  • Allow for a hollow space between the gravel of about 30%.
  • Stay about 2 to 3 meters away from the foundation and trees.
  • Check the vent. The downspout sometimes also functions as a sewer vent. If necessary, install an alternate vent.
  • Tip: replace the gravel with lava rock. Lava rock has a hollow space percentage of 50%. Then you will need a smaller pit.

Points of interest

  • In a topsoil with a lot of clay or loam, this measure is less suitable because water does not sink quickly into the soil.
  • Allow for at least 25 cm of coverage.
  • Dig the pit to a depth of about half a meter above the average groundwater level.
  • Choose gravel pellets of about the same size.
  • Do not use a root cloth, but a geotextile cloth.
  • Situate the vent and overflow pipe in a lower part of the garden. During peak downpours, rainwater that no longer fits into the gravel pit can be collected in it.
  • Use a leaf and sand trap to prevent siltation. A leaf trap can also serve as an overflow in extreme cases.
  • Allow for a hollow space between the gravel of about 30%.
  • Stay about 2 to 3 meters away from the foundation and trees.
  • Check the vent. The downspout sometimes also functions as a sewer vent. If necessary, install an alternate vent.
  • Tip: replace the gravel with lava rock. Lava rock has a hollow space percentage of 50%. Then you will need a smaller pit.