Designing Water Features for Success: Fish, Wildlife & Safety

Water Features: Designing for Success

Designing for Success

Aesthetics are largely determined by the open water configuration, whether complementing planting or as the main feature. Plants provide colour, form, height — together they create the overall effect.

Keeping Fish Happy

Fish add life and biological pest control. Common goldfish, shubunkins, golden orfe, green tench are resilient — survive winter in 30 cm (12 in), preferably 45 cm (18 in) to protect fancy varieties. Surface area must be large for gas exchange.

Well-planted pools with liberal submerged aquatics provide cover. Fish enjoy sun but need respite in heat — submerged/floating foliage helps. Protection from cats/herons during growing season; in winter, place rocks on pool floor for shelter. Ready-made shelters available for small ponds.

Plant marginal shelves fully — vacant spots attract bathing birds, which may carry pesticides on feathers (lethal to fish). Provide separate bird bath, keep margins full.

Bearing Wildlife in Mind

Pools attract hedgehogs, etc. Heavily planted margins exclude birds but risk small mammals drowning in deep areas. Provide escape route: simple narrow board with cross-pieces. Some pre-formed pools include ramps.

The Pool Profile

Design must please the eye and meet aquatic life needs. Most important practical element: pond profile. Four plant groups with specific needs:

• Waterlilies/deep-water aquatics: Need deeper water, rarely >90 cm (36 in). Popular lilies thrive at this depth. Balance sensible depth with generous surface area. Shallower options exist (pygmy lilies in 15 cm / 6 in), most deep-water subjects adapt. Consider fish welfare.
• Submerged aquatics: Need 45–90 cm (18–36 in) for cool summer temps. Deeper = dark, impairs growth; shallower = heat, decomposition. Most flower at/just above surface, grow to water depth. Exceptions: short hair grass (Eleocharis acicularis) affected by depth extremes; rootless hornwort (Ceratophyllum demersum) suspends at optimal depth.
• Floating plants: Not depth-bothered, but shallow water heats in summer. Small floaters (frogbit) resent warmth, may rot; fairy moss tolerates it. Select carefully for forced conditions. Deep water = colder spring, delays overwintering plants (turions on pool floor emerge weeks later).

Marginal Areas & Bogs

Marginal shelves: best for interesting aquatics. Variable depth (damp to several cm water) — natural stream/riverside dwellers tolerate fluctuation. Ideal: generous shelf accommodating standard basket in width/depth + 5 cm (2 in) water over basket. Distribute margins as long as possible for visual coordination. Short lengths only suit formal pools with architectural plants (reeds/rushes).

Bog garden: valuable addition, ties pool to garden, grows difficult plants. Plan from start — difficult to add later. Natural extension of pool. Easy with flexible liner.

Designing with Safety in Mind

Ponds always potentially dangerous, especially for children. Reduce risks: max depth ≤90 cm (36 in). Planting, shallow margins, bog extensions reduce slip hazards. Edging: paving wide enough for foot, non-slip. No gaps for high heels. Electricity: only armoured waterproof cable, RCD circuit breaker. Pump removed in winter; if fish kept, may need heater — connection beneath removable paving slab (manhole cover style).