A climate buffer is a feature or area that absorbs the consequences of a changing climate by holding water back: rainwater is given the chance to soak into the ground, it recharges the groundwater, and it can be drawn on again during a long dry spell. A buffer therefore dampens two opposite extremes at once — too much water and too little.
The term is used at several scales. At landscape scale people speak of natural climate buffers: nature areas managed so that they store water, counter salinisation or strengthen the coast. At plot scale a climate buffer is simply the feature in your own garden or under your driveway that catches the downpour.
Where it applies
- Swale — a shallow, planted depression in which rainwater stands briefly and slowly soaks away. It only works on permeable ground with enough clearance to the water table
- Soakaway crates or gravel trench — underground storage below a garden, terrace or drive; crate systems have roughly 90 to 95 per cent void space, gravel only about 30 to 40 per cent, so gravel needs a far larger volume
- Green roof — holds rainfall and releases it with a delay
- Pond, ditch or sunken planting bed — simple, visible buffering
- Water butt — useful for reuse, but at 100 to 300 litres far too small to store a storm
| Soakaway crates | Roughly 90 to 95 per cent void space |
|---|---|
| Gravel trench | Only about 30 to 40 per cent void space, so it needs a far larger volume |
Practical tips
- Test the permeability first — dig a hole, fill it with water and watch how fast it drops. On sand infiltration works well; on clay or loam it usually needs extra measures
- Keep clear of the wall — place an infiltration system at least a few metres from the foundation where you can, and always with fall away from the building
- Provide an overflow — every buffer fills up eventually; decide in advance where the water goes then, and it should not be the crawl space
- Filter out the debris — leaves and silt block an infiltration system; a leaf trap or silt trap upstream extends its life considerably
- Work with a range — many Dutch municipalities ask for 20 to 60 mm of storage per square metre of paved area; the exact requirement is in the local stormwater rules
Related terms
- Climate-adaptive building
- Climate mantle
- Infiltration
- Green roof
- Rainwater drainage
Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.