Winter Pond Draining: Why Keeping Water In Protects Your Liner

Don't Drain Hard Plastic/Liner Ponds

Two hard plastic ponds (one with liner overlay) in a cold climate. Owner wants to drain and bring fish in. Bad idea.

Risks of Empty Ponds in Winter

• Groundwater buoyancy: Rain/snowmelt lifts empty shell → cracks, warps, floats.
• Freeze-thaw on dry liner: Plastic becomes brittle, cracks at folds.
• UV degradation: Exposed liner degrades fast.
• Spring refill hassle: Re-leveling, leak testing, re-cycling.

Better: Winterize In Place

1. De-icer (keep hole open).
2. Aerator at mid-depth.
3. Stop feeding at 50°F.
4. Net for leaves/predators.

Cost Comparison

De-icer ($30–50) + aerator ($25) + electricity (~$15/mo) <<< liner replacement ($200–500) + labor + fish stress.

Only Drain If

Pond is <18" deep, no de-icer option, and you have indoor housing ready. Even then, leave 6–12" water + de-icer.