Water and the Geelong Botanic Gardens

The Geelong Botanic Gardens are over 150 years old. Established in 1851, the gardens and Eastern Park have become important green spaces in Geelong.

The Gardens showcase historical and modern landscapes with a wide variety of plants from around the world. Each plant has unique water needs, influenced by their native environments.

Certain areas, such as the 21st Century Garden, are designed to require minimal water, while others, like the historic 1851 Garden, require more, particularly during the summer.

To keep the Gardens thriving, irrigation can use up to 28 megalitres of water each year, depending on the weather.

Drought and the Gardens

In December 2006, the Barwon Region, which includes the Gardens, went from Permanent Water Saving Restrictions to Stage 4 Water Restrictions. An exception was made to use tap water to keep this historic garden alive, which has heritage trees and important plant collections.

The 21st Century Garden was designed to use very little water, even during dry times. Other areas, like the 1851 Garden, need more water, especially in summer. During Stage 4 restrictions, watering was minimized to just enough to keep the garden going.

Many trees in the Gardens and Eastern Park suffered from the 10-year drought and later dry years. Over 30 important trees were supported through the drought with extra tank watering.

Water Management

In 2011, the City of Greater Geelong received joint funding from the Australian Government’s Water for the Future program. This funding was used to develop a stormwater storage and reuse facility in Eastern Park to reuse treated stormwater on the Gardens and park trees.
The project was supported by the Eastern Park and Geelong Botanic Gardens Strategic Plan Master Plan, adopted in January 2008. This plan showed the opportunity to reuse stormwater and develop a dam on the site of the 1860s Bunce’s Lake.

The aim is to reduce reliance on potable water by replacing it with treated stormwater. For more details, refer to the information page on the Eastern Park Stormwater Harvesting Project.
Stormwater is captured from the 47-hectare suburban area of East Geelong. The water is treated through sand and UV filters and then pumped to storage tanks with a 250,000-liter capacity within the Gardens.

Linked to this project was the need to replace the irrigation system to maximize water use, especially treated stormwater.

The irrigation replacement was scheduled over four years, starting in late 2013. Detailed analysis of soil, plant water needs, soil disturbance impact, and best practices for botanic garden irrigation was conducted before the detailed design was developed.

Where staff or community members might come into contact with spray from water, potable water is used. These areas include the nursery, glasshouses, and the cool temperate rainforest. Watering is done at night to minimize exposure and maximize water application.

Best practices are used in scheduling and managing the computer-controlled weather-based irrigation system. The onsite weather station provides current climatic conditions to the central controller to ensure effective irrigation. Factors like soil-water holding ability, rooting depths, and climatic conditions are considered. Efficient irrigation scheduling means the right amount of water is applied at the right time.

How water is applied to garden beds and lawns varies depending on plant needs. Methods include spray irrigation, hand watering, and drip irrigation.

Horticultural staff at the Gardens are trained in efficient irrigation management and best practices for water management. Regular independent water testing is conducted to ensure the treated water is safe for reuse.