Birchip Cropping Group (BCG)

Installing a wildlife pond

Background

A completed wildlife pond.

A wildlife pond is an in-ground water source designed to provide habitat for wildlife. Ponds are inexpensive, easy to install and water efficient. They provide an important home for frogs, a refuge for turtles and a vital drinking source for many species of birds.

The BCG publication ‘Farmer’s guide to installing a wildlife pond’ outlines the concept of wildlife ponds and gives directions on selecting a suitable site. This factsheet provides additional information about wildlife ponds, including a list of the materials required and detailed instructions on how to install a wildlife pond like the one below in five easy steps.

Materials required and cost

The materials needed should be available from an agricultural supplier or hardware store. Costs may vary depending on the supplier and the following costs are a guide:

Plastic pond liner (square of dam-lining plastic, 6x6m) $70
Liner protector (square of shade cloth, 4x4m) $50
Float valve (¾ inch arm float), float and string $40
Poly connector to connect float valve to ¾ inch poly pipe $5-6
Anchor for float valve (see Step 4) $10

Step 1. Digging the hole

Smoothing the sides of the hole.

The ideal hole for a pond is a 5m circular depression dug to about 1m deep, bowl-shaped, with sloping sides.

A front-end loader or excavator can be used to dig the hole.

Retain the excavated soil close by as it will be used to cover the liner.

Smooth the sides with a spade and remove any rocks, tree roots or other sharp or pointed objects that might puncture the plastic liner.

Step 2. Lining the pond

The excavated hole with plastic liner and shade cloth in place. Despite its shallow appearance, this hole is about 1m deep.

Lay the plastic liner in the hole so that it reaches or just overlaps the rim of the hole, then place the shade cloth across the bottom of the hole.

Take care when stepping on the sides of the plastic as it is slippery and can easily be punctured.

Trim the corners of the liner to suit the rounded shape of the pond.

“Retain the excavated soil close by as it will be used to cover the liner.”

Step 3. Replacing the soil

The soil may need compacting after spreading to better hold it in place

With the plastic liner and shade cloth in position, the excavated soil can now be replaced. Remove sticks, roots and other hard objects from the excavated soil and be very careful when dumping the soil if it contains hard lumps of clay that can puncture the lining.

Replacing the soil is best done using a front-end loader or excavator. Place buckets of soil in the centre of the pond then spread the soil up the sides of the pond. The liner may need holding in place when the first soil is dropped in. Keep placing soil in the pond and around the edge until the entire plastic liner is covered.

Soil should be spread to a depth of at least 20cm across the bottom and sides of the pond; the thicker the layer of soil, the better. Some compaction of the soil may be required to ensure it stays in place.

Step 4. Adding the float valve

The float level can be set by varying the length of the string so that the float sits about 10cm from the top of the pond.

The water level in the pond is maintained by a float valve mechanism. The float valve is submerged in the pond and anchored to the bottom. To make the anchor, weld a steel washer with an internal diameter of 25mm onto the end of a length of steel rod 13mm thick (like concrete reinforcing rod), and cement the rod in a block of concrete. A bucket can be used as a mould for the block.

Place a plastic bag in the bucket, mix some concrete in the plastic bag and set the steel rod vertically in the middle. Remove the block from the bucket when the concrete has set and peel the plastic bag off the outside.

Place the concrete block in the bottom of the pond and attach the float valve.

“The water level in the pond is maintained by a float valve mechanism.”

Step 5. Filling your pond with water and plants

Adding logs and branches

The pond is now ready to be connected to your piped water supply. The soil will absorb water and turn soft after filling. The edge of the pond can be slippery and dangerous until the soil settles. Take care to keep children and animals away from the edge.

Logs and branches can be placed in the pond to provide habitat for aquatic animals and as perches for birds.

Step 5 (cont.) Filling your pond with water and plants

Aquatic vegetation provides habitat for fauna

The ponds will provide greater wildlife benefit if planted with aquatic vegetation. Rushes and sedges can be planted around the edge of the pond while plants with floating leaves, such as water ribbons and nardoo, can be planted in the deeper areas. Details of aquatic plants and plant suppliers can be found on the BCG website.