Eastern Park Stormwater Harvesting

We harvest stormwater from the East Geelong drainage system. We store it for re-use in the dam in Eastern Park.

Water from the drainage system is diverted to the dam.  It is stored in the dam until we need it for irrigation.

We are use the water for:

  • watering newly planted street trees in Geelong and Eastern Park

  • watering the Geelong Botanic Gardens

Using recycled water reduces how much drinking water we use for irrigation.  The stormwater harvest dam could save up to 30 million litres of drinking water each year.  The amount of this saving depends on the amount and timing of rainfall we receive.

Location in Eastern Park

The water storage dam is located in the southern part of Eastern Park. 

This exact site in Eastern Park was a lake until 1925 when it was filled in to create a cricket field.

Historical Map of Eastern Park
1925 Aerial View of Eastern Park

How does it work?

The dam is designed as a stormwater harvesting and reuse system. Water harvested from stormwater drains in East Geelong goes through a gross pollutant trap.  This picks up large bits of rubbish. 

Water goes into a rock filled sediment pond and settles.  When this pond is full it overflows into the main dam.  It holds about 4 million litres and takes up an area of approximately 7000 square metres.

The dam has an important practical function in storing water. We wanted it to fit well in the parkland so it has been designed to look like a natural water body. This helps to improve the existing flora and fauna biodiversity of the area.

Indigenous plants have been planted around the water's edge to assist in the water cleaning process. Water birds including ducks and herons come regularly and other animals including bats drink from the dam.

Walking paths

A walking path around the dam connects to the Eastern Park Circuit pathway. This makes it easy to walk from Ryrie St into the park and to the Geelong Botanic Garden. 

The dam is similar to other water bodies around Geelong like Grinter Reserve, McLeods Watering Hole (Drysdale), Ballyang Sanctuary (Highton) or Seagull Paddock (North Geelong).

Water depth

From the water’s edge the slope of the batter is gradual for 10 metres before reaching a maximum of 2 metres deep when full.

The edges of the dam have been designed to Royal Surf Lifesaving Guidelines to have a gradual slope. Plants create a physical barrier to deter people from getting into the area.

The system is designed to only draw off the top 1 metre for re-use. Water will always be in the basin unless we have abnormally long dry periods.  When this happens the natural evaporation can dry out the dam.

Where will the water come from?

We harvest the rain falling on a 47 hectare suburban area of East Geelong.  It flows into the existing stormwater pipes and is then diverted into the stormwater harvest system instead of flowing into the open concrete channel, between the East Geelong Golf Club and CSIRO.

Being an older suburban catchment the stormwater quality is very good.

Heritage, cultural and environmental significance considerations

A significant amount of investigation was done to determine the impact of this project on the existing flora, fauna and rich heritage values of this site. Heritage Victoria granted a permit for this project. 

A flora and fauna study provided us with a thorough understanding of the site and determined where the best locations for infrastructure would be.

No trees needed to be removed as part of the project.  In fact new trees have been added to the ring of Red Gums surrounding the dam.

Our Sustainable Water Use Plan identified the Geelong Botanic Gardens in the top 10 water users for Council. The Botanic Gardens is a unique natural and cultural resource for our community.

This project has been modelled to replace approximately 90% of the 30 million litre water demand at this site. The water is  used for Council’s ongoing tree maintenance and establishment program for Eastern Park.

Mosquito concerns

Mosquitoes thrive in stagnant and shallow water. This system has been designed to replenish itself approximately 20 times a year. Therefore the water will be constantly turned-over with new stormwater supplies.

The water is shallower around the edges for safety but most of the water is too deep for mosquito breeding. The site has been added to Council’s sites to monitor for mosquito populations and will be treated if required.

Water quality

The stormwater comes from an old suburban area of East Geelong with no runoff from industry. We have a high reuse demand for this water and inflows are approximately 70 million litres per year.

The water will turnover around 20 times a year and greatly reduce the risk of the water becoming stagnant, unsightly and smelly.

A litter trap has been installed prior to the water body to capture everything down to 5 millimetres in size and reduce heavy metals and phosphorous loads.

Vegetation has been designed around the edges of the water to assist in the removal of nutrients.

The water is treated with a sand filter to break all particles down to 200 micron in size and ultra violet light to reduce ecoli and pathogens before being used for irrigation.

The Australian Government’s Water for the Future initiative contributed $415,000 and Council $515,000 to this $930,000 project.

Relocation of soil

The spoil generated from the excavation was used to improve the level of the adjacent oval. The remaining spoil was used to create a slightly raised embankment on the eastern side of the water storage.

This embankment forms the base for the pathway for visitors. No soil was required to be taken offsite greatly reducing the need for heavy vehicles to leave the site and disturb the surrounding neighbourhood.

Page last updated: Tuesday, 29 October 2019