Natural Pond Handbook

12 · Natural Swimming Ponds

Illustration of a natural swimming pond
A clear swim zone plus a planted regeneration zone.

A swimming pond (natural pool) lets you swim in living, chemical-free water. The trick is separating the swim area from the regeneration zone.

Two-zone design

  • Swim zone: deep (1.8–2.2 m), lined, clear, no plants — for swimming.
  • Regeneration zone: shallow planted area (often equal to or larger than the swim zone) that biologically filters the entire volume.

Water is pumped from the swim zone through the plant zone and back. The plants and gravel do all the filtering — no chlorine, no salt.

Key differences from a garden pond

AspectSwimming pondGarden pond
Plant zone size50–100% of swim area10–30%
DepthDeep swim basinVaried, shallower
TurnoverFull volume 1–2×/day minGentler
FishMinimal or noneOptional
Reality check A swimming pond needs serious planted area and flow to stay clear with bodies moving through it. Undersize the plant zone and you will fight algae all summer. Budget for a proper regeneration basin.

Construction outline

  1. Excavate swim basin and regeneration basin (can be side-by-side or concentric).
  2. Line both with EPDM; separate them with a low wall or grade.
  3. Fill regeneration zone with gravel + aquatic planting.
  4. Install a robust pump moving water from swim → plant zone → back.
  5. Add a skimmer to catch oils/suntan lotion and surface debris.