Peter Hopper Lake revitalisation

Peter Hopper, the former long-serving shire engineer who the lake is named after, checks in on the project’s progress.

Improvements for Peter Hopper Lake

Peter Hopper Lake is one of the City of Whittlesea's largest waterbodies and attracts visitors from the local community and beyond. Built in the mid-1970s, it is situated within Redleap Recreation Reserve in Mill Park.

In recent years, the lake has experienced numerous algae outbreaks and water quality issues. While various treatments have had some success in restoring water quality, the effects have not been long-lasting and further work is required to improve the long-term health of the lake.

Council’s expert engineers and environmental scientists have worked with specialist consultants on a plan to end the cycle of algae blooms and return the lake to good health.

Project progress

Stage two: January 2025 to late 2025

The second stage of the revitalisation project commenced in January 2025.

Under the supervision of a qualified ecologist, we have begun the process of lowering the lake’s water level to allow for the next phase of works.

This includes removal of the jetties and central island, construction of a new pollutant trap, sediment basin, raingarden and floating nesting platform, and installation of pumps to recirculate the water.

Stage one: February 2024 to June 2024

The project’s first stage started in February 2024 and concluded in June 2024. It involved dredging the lake to remove silt and other pollutants that had built up on the lakebed over decades. Approximately 3000 cubic metres of sediment was removed from the lakebed during this process.

This approach to removing the pollutants had the benefit of maintaining the amenity of the lake, reducing potential noise and odour issues and reducing the impact on flora and fauna.

Wildlife management

Council and its ecologist are conducting all wildlife management activities in accordance with the conditions set out by the Department of Energy, Environment and Climate Action (DEECA).

During the second stage of works in March 2025, it became apparent that some turtles had moved from the project area.

In response, the project team, contractor and ecologist conducted a thorough examination of the temporary fencing and fortified it in a number of places. The fence will be monitored daily.

In early April 2025, Council erected signs around the site to inform residents of the preferred procedure should they find a turtle outside the fenced area. For more information, refer to Caring for the lake's turtles signage(PDF, 4MB).

Council is also working with the contractor and ecologist on the possibility of developing a refuge for the turtles within the site.

An application to translocate turtles found outside the construction zone was refused by the State Government on biosecurity grounds. As a result, Council is only permitted to relocate turtles back into Peter Hopper Lake.

Improving water quality

Several factors have contributed to the lake's poor water quality. The upgrade will address these issues to ensure the lake remains a place for the community and wildlife to enjoy for years to come.

Mud

Peter Hopper Lake has accumulated large quantities of silt from stormwater run-off that feeds into the lake.

Silts bind all sorts of contaminants as they wash off the catchment, including phosphorus which impacts the lake's water quality through over-nutrification, leading to algae blooms and low oxygen levels in the water.

We will remove all silt from the bottom of the lake and install a gross pollutant trap upstream to catch coarse organic debris.

A sediment pond will be built at the lake's inlet to capture finer silts before they enter the lake. These will protect the lake from ongoing natural contamination in the future.

Water quantity

The lake's catchment does not currently supply enough water for the lake to refresh itself regularly.

We'll be increasing the lake's inflow of water and upgrading the lake's overflow capacity in order to achieve more water turnover.

Water circulation

Peter Hopper Lake is a large waterbody and movement of water is dependent on stormwater flowing in and out of the lake.

This means that between rain events, water does not move around as much.

To help move the water regularly and avoid stagnation, we'll be installing a pump system at the lake.

Nutrients

Nutrients, such as nitrogen and phosphorus, occur naturally but much of the nutrients in our waterways come from human activities such as fertilisers or from animal droppings.

When there is an excess of nutrients in the water, it can lead to algae blooms.

To continuously filter out excess nutrients, we're constructing a specifically designed raingarden in the northern part of Redleap Reserve.

Lake water will be pumped to the raingarden and be filtered through a sandy soil and nutrient-hungry vegetation before making its way back to the lake.

Community consultation

We received overwhelmingly positive feedback on the revitalisation proposal during the public consultation period between March and June 2023.

The feedback was received through our online Engage page, our on-site pop-ups, and consultation with the Friends of Peter Hopper Lake Group. The main themes can be summarised as follows: