They're wide but shallow
It is often the case that park visitors may drop personal items in the pond, from glasses to cameras, and even bikes. Our Rangers are often required to retrieve these items, but many people don’t realise that specialised diving equipment isn’t necessary. The ponds may be big and wide, but they aren’t very deep.
In the style of 19th century urban park design, the ponds in Centennial Parklands are quite shallow – mostly less than 2 metres deep at their lowest points. Towards the shoreline, the ponds are often ankle to waist deep at most.
This shallowness of pond design is a European tradition, but does bring its challenges in an Australian climate. A very large, but shallow, surface area of water can suffer from evaporation loss in hot weather. Since the ponds are stormwater fed, in periods of prolonged dry weather or drought the ponds can rapidly become depleted.
This means that the health of our ponds are in our hands, so we have several strategies in place to reduce the onflow and impact of stormwater pollutants in the ponds.
- use of ‘Gross Pollutant Traps’ at key stormwater entry points to capture larger waste items;
- aquatic plantings which provide stability for banks and improve the quality of the water by filtering out some dissolved toxic pollutants such as phosphorus;
- the addition of new islands and underwater berns to prevent water from becoming stagnant;
- regular water analysis and occasionally, use of an aerobic bacterial treatment method that helps to reduce built up organic matter, nutrients and various other organic compounds