Regional goals and objectives
The regional goal for water resources from the Port Phillip and Westernport Regional Catchment Strategy is:
Sustainable water use and healthy waterways, wetlands, estuaries, coasts, bays and seas.
Port Phillip and Westernport Regional water objectives (WOs) are:
This part consists of one section (Section 3) which focuses on water within the catchment, specifically the catchments surface waters the waterways and wetlands. As the catchment has no declared Groundwater Management Areas and no parts of the catchment are used for potable water supply these issues are not considered in the current document.
Chapter 3.1 looks at the drainage functions of the waterways, wetlands and floodplains, and at their management. Chapter 3.2 focuses on water quality of the waterways, and the influences from the catchment and opportunities for water quality improvement. Chapter 3.3 looks at the animal and plant life of the waterways and wetlands, how they are influenced by water quality and quantity, and how habitat can be improved.
The waterways of the catchment support important, and in many cases endangered, communities of native plants and animals and are in turn improved by these biota.
The waters of the Merri and its tributaries are highly valued by the community. The waters provide a fundamental recreational element of the linear parklands of the waterways. This is largely through a visual contribution to the recreational experience as the waterways are generally too small, and/or too polluted to allow for contact recreation. The urban lakes at Lake Reserve Coburg, Edwardes Lake Reservoir and Jack Roper Reserve Broadmeadows are especially important in this regard. The waters and floodplains provide important habitat for flora and fauna of the corridor, and these elements also contribute to the recreational experience. Park users are acutely aware of and concerned about the quality of the water in the catchment waterways, and in particular about litter levels in and near the water (see section 4).
In terms of drainage and flood management, the waterways provide an important stormwater and flood conveyance service. The channel cannot (and should not) convey larger flood events and floodwaters spill out into adjacent floodplains where they are available and have not been lost to development.
The problems of water quality and litter (discussed in chapter 3.2) and flooding (chapter 3.1) in the waterways must be managed at a catchment level, because the sources of these problems are distributed across the catchment. Management of these issues only within the waterway corridors can be only of limited effectiveness. On the other hand, reliance only on catchment-based solutions requires the cooperation of everyone in the catchment. In practice both strategies are needed. It also is important that activities to improve water quality, reduce litter, and protect people and property from flooding are integrated with habitat protection and improvement.
Whilst no parts of the Merri catchment are used for potable water supply, waters of the catchment do form an important resource for stock watering, and a small amount of irrigation for agriculture and recreational purposes.
Groundwater has been an issue in planning for quarries along Merri Creek as the Merri is largely spring-fed in its middle reaches, quarrying may lead to reduced flows.
The Port Phillip and Westernport Regional Catchment Strategy forms the starting point for considering objectives for water. All of the regional objectives (shown below) are relevant to the waters of the Merri Catchment, even RCS-W03 as pollutants in the Merri largely end up in Port Phillip Bay, and a number of migratory fish rely on marine areas as part of their lifecycle.