Key Takeaways
- Melbourne Water reduced groundwater pumping through the Quiet Lakes from 730 megalitres to 20 megalitres in 1991, leading to a decline in water quality.
- The closure of the outlet from Lake Carramar to the tidal lakes has caused the lake to become stagnant, resulting in toxic water containing cyanobacteria.
- Melbourne Water proposes to introduce bore-flushing to Lake Carramar at a cost of $300,000 to improve its water quality.
- Residents are willing to pay a reasonable charge for improved water quality, but some may be hesitant to pay additional fees.
- The Quiet Lakes were developed in the 1970s, and the original permit for groundwater pumping has not been amended, potentially putting Melbourne Water in breach of its obligations.
Introduction to the Quiet Lakes
The Quiet Lakes, a series of three lakes in Melbourne’s outer south-east, have been plagued by poor water quality for over 30 years. In 1991, Melbourne Water cut the volume of groundwater pumped through the lakes annually from 730 megalitres to 20 megalitres, which had previously flushed the lakes every three months and maintained a swimmable standard of water quality. This reduction in groundwater pumping, combined with the closure of the outlet from Lake Carramar to the tidal lakes, has turned the lake into a stagnant body of water, resulting in toxic water containing cyanobacteria.
Impact on Residents
The residents abutting the Quiet Lakes, especially Lake Carramar, have suffered for over 30 years with toxic water containing cyanobacteria, which is harmful to humans, wildlife, and fauna. The association president, Alison Yates, argues that under the management of Melbourne Water, the Quiet Lakes were transformed from a residential community enjoying a lifestyle built around lakes, in which they were safe to live beside and in which they could swim, into a seething mass of blue-green algae which included several toxic varieties. Residents like Heather Smith, who has lived in a house on Lake Carramar since 2012, have experienced the algae problem firsthand, with some summers being particularly intolerable.
Proposed Solution
Melbourne Water proposes to introduce bore-flushing to Lake Carramar at a cost of $300,000 to improve its water quality. The cost will be shared equally across customers at all three lakes, enabling the lake network to be managed as a complete system rather than separate entities. During consultation with residents, Melbourne Water also proposed optional additional charges for carp control, algae treatment, and reducing phosphorus levels. Residents like Heather Smith are willing to pay a reasonable charge for improved water quality, stating that "you don’t get much for a free lunch, you might as well suck it up and pay what you have to pay."
History of the Quiet Lakes
The three lakes were developed in the 1970s when a swamp was drained to build a housing estate. The developer, Gladesville, obtained a permit from the rural water authority to pump the lake with 730 megalitres of groundwater. However, the residents’ association argues that the original permit has not been amended, potentially putting Melbourne Water in breach of its obligations. The houses around the Quiet Lakes are a beacon for retirees, and the residents are among a small number of property owners in Melbourne’s outer south-east who must pay Melbourne Water a separate direct service charge on their water bills for managing what are considered private assets.
Response from Melbourne Water
Melbourne Water executive general manager Sue Jackman stated that the corporation received more than 8000 pieces of feedback about its price submission, including from Patterson Lakes residents. The feedback showed that most residents supported a price increase to cover the cost of including Lake Carramar, to provide consistent service and recreational value across all three lakes. Jackman noted that residents preferred expanding bore-flushing to include Lake Carramar, in addition to lakes Legana and Illawong. The introduction of bore-flushing to Lake Carramar is a step towards improving the water quality of the Quiet Lakes, and residents are hopeful that it will make a positive impact on their community.
