Irrigation from artificial paving stones?

[Stephen Tashi]

Would it be possible to design a paving stone with a reservoir of some kind under it that would let water drain through the stone into the reservoir and then very gradually seep into the ground around the stone?

In a dry climate, the goal would be to create an area of a lawn that was part green and part paving. The paving stones would hopefully make better use of natural rain and (unnatural) watering by capturing water that would otherwise run off or evaporate and releasing it slowly underground. I'm visualize paving stones of about 1 ft x 1 ft and about the same area of grass in between them.


My thoughts on such a design:

The paving known as "pervious concrete" could be used for the paving stone itself, or one could cast as stone with channels around the edge and small drain holes in them to let water pass through.

A reservoir of only water under the stone might breed mosquitoes or bad odors. Perhaps the reservoir must actually be a bed of absorbent material like sand or clay.

A critical goal of the design is to slowly release water to the areas adjacent to the stone instead of losing the water by letting it percolate into the ground directly under the stone. The bottom and upper sides of the reservoir should be impervious to water. If the reservoir is concrete, perhaps those areas of the reservoir can be sealed.

I don't have a good intuiton for how quickly water would seep thorugh the unsealed parts of a concrete reservoir. (How fast you want the reservoir to empty would depend on the climate.) Do concrete swimming pools need a special coating to keep the water from seeping out? Or is the coating just to keep the concrete from getting into the water?

In some soils and climates, perhaps no elaborate reservoir is needed. Perhaps you could simply bury a relatively impervious slab of concrete 10 inches or so directly under the paving stone and accomplish the goal.

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My thoughts are just for a homeowner's type project. Anyone who wants to try this as an academic investigation or commercial venture is welcome to the idea.

 

[etudiant]

Permeable paving is an excellent idea. The objective is to capture the rain where it falls, rather than having it sluiced into gutters, producing damaging runoff that needs to be separately dealt with.
There is cement paving designed to achieve this, with holes in the pavers. The pavers also have ridges on them, to help ensure that the grass growing in the holes is not crushed too much by car tires. The only quibble is that in summer, the pavers tend to get pretty hot, which is not great for the grass, while in winter the surface traps snow and ice, so it is not easily plowed.

 

[Dr_Morbius]

Watch this episode of This Old House and in the first 4 minutes you'll see the answer to your question.

http://www.thisoldhouse.com/toh/tv/video/0,,20618950,00.html

 

[Stephen Tashi]

Watch this episode of This Old House and in the first 4 minutes you'll see the answer to your question.

http://www.thisoldhouse.com/toh/tv/video/0,,20618950,00.html

It's not the answer to my question. There is no lawn interspersed with the pavers.

 

[alphy]

I find this concept intriguing and potentially feasible. The idea of using pervious concrete or creating channels and drainage holes in paving stones to allow water to pass through and be collected in a reservoir is a creative solution to the issue of water runoff and evaporation. It could also potentially help with water conservation by slowly releasing the water into the surrounding ground instead of it being wasted.

However, as you mentioned, there are some practical considerations that would need to be addressed. The type of material used for the reservoir, as well as its size and location, would need to be carefully chosen to prevent issues like mosquito breeding or odors. Additionally, the rate at which the water is released from the reservoir would need to be carefully controlled based on the climate and soil conditions.

Further research and experimentation would be needed to determine the most effective design for this type of irrigation system. Overall, I believe this idea has potential and could be a valuable solution for homeowners in dry climates looking to incorporate both paving and green space in their yards.