Protecting Our Creeks & Waterways
What Are Watercourses?
When we picture a creek or waterway we often think of rock pools and waterfalls bursting with vegetation and wildlife. In many areas of our catchment, waterways remain a picturesque part of the environment, but in other areas this is no longer the case. In many developed areas there is a trend to pipe or modify creeks and waterways, to transport run-off as quickly as possible. This effectively eliminates the waterway’s natural ability to improve water quality before it enters the Lake or the ocean. While modified drainage channels and waterways may be less aesthetically pleasing than natural creeks, they still play an important environmental role, and benefit from our care and protection.
Why Are Watercourses Important?
A catchment area of approximately 605 km2 drains to Lake Macquarie via a network of thousands of watercourses, varying in size from large creeks such as Cockle Creek, Winding Creek and Dora Creek to small roadside drains. Dora Creek drains a relatively natural landscape from the Watagan Mountains and Martinsville, while Winding Creek drains the urbanised area of Charlestown, Cardiff, and Glendale.
An important part of all watercourses is the area of land adjacent to the waterway which is known as the riparian zone. Native vegetation along watercourses (including the creek bank) is vital to maintaining these areas in a good condition.
Where this vegetation is damaged or removed, the stream condition can deteriorate and downstream water quality can suffer. Riparian zones and waterways play an important role in our environment including:
- Providing habitat for plants and animals, including a number of rare or endangered species.
- Reducing pollutant loads by helping to filter litter, sediment, and excess nutrients from stormwater runoff; helping to maintain the quality of our Lake and beaches.
- Shading watercourses, to control water temperature and prevent excess growth of water plants.
- Providing vital breeding habitat and nursery areas for fish and other aquatic species.
- Offering a natural landscape for all to enjoy for relaxation or recreation.
Watercourse Degradation – What is the Problem?
There are over 12,000 stormwater drain inlets along streets in Lake Macquarie, all of which lead to waterways – creeks, the Lake and the City’s beaches.
In many areas the riparian vegetation has been removed or is in such a degraded state that it cannot perform its environmental role. Degraded watercourses can suffer from:
- Reduced water quality, as the capacity to filter nutrients and sediment is reduced. This can lead to problems such as algal blooms, turbid or muddy water, and reduced recreational amenity.
- Erosion and sedimentation of the watercourse and in the Lake.
- A reduction in habitat for plants and animals which can result in a loss in biodiversity.
- The destruction of seagrass beds in Lake Macquarie due to muddy water blocking out the light.
In the past, development of the urban landscape has not allowed for adequate infiltration of rainwater. Bushland, grassy paddocks and streams, where rainwater once soaked into the ground, have made way for hard surfaces such as rooves, paving, roads and concrete pipes. As the developed area of the catchment increases, so does the quantity of stormwater and the amount of pollutants flowing into surrounding watercourses and drainage channels.
Development of a catchment can result in 4-6 times as much total runoff compared to pre-development levels. As a result, watercourses have to adjust to the increased quantity and velocity of water, leading to erosion of the banks and bed. In smaller, more frequent rainfall events (where most rainfall would normally soak into the ground), runoff volumes in developed areas can be increased by up to 40 times.
What You Can Do!
Many of the creeks and waterways in the Lake Macquarie catchment are already degraded, and need protection and rehabilitation to prevent problems worsening. Unfortunately, some people see urban waterways as an eyesore with little environmental value, and treat them as such.
They become dumping grounds for grass clippings, litter and garden rubbish.
Whether their condition is good or poor, waterways of all shapes and sizes play an important environmental role. Some simple ways that you can help to protect and improve waterways include:
- Recognising your local creek, waterway or drainage channel as a living, dynamic system rather than simply a structure to convey stormwater runoff.
- Preventing pollutants from entering stormwater by washing your car on the lawn, avoiding excessive use of fertiliser, erosion-proofing your yard with mulch or vegetation, and recycling your garden wastes with a compost bin.
- Helping to repair and rehabilitate our waterways by joining your local community Landcare group.
- Reducing the amount of runoff from your block by investing in a rainwater tank. This will not only provide free water but will help reduce the volume of stormwater entering our waterways. Another way to do this is to use porous paving rather than concrete, and to construct swales and detention areas in your garden to encourage water to soak into the ground.
- Protecting and restoring streambank (riparian) vegetation to improve water quality, prevent erosion, and provide habitat.
Giving Creeks an Identity
Many small creeks and drainage lines around the Lake are anonymous. Even if they have a local or neighbourhood name, it may not be recognised on official maps or street directories. Council has found that people tend to take more care of creeks and waterways that have a name. To find out if your local waterway has a name, or to suggest a name for it, contact the “Creek Rediscovery Program” at Council’s Environmental Systems Department. They will help explain the guidelines for names, and the procedure for nominating a name with the NSW Geographic Names Board.
How are Creeks & Waterways Protected?
The Protection of Watercourses and Drainage Channels Policy
This policy of Lake Macquarie City Council was approved in February 2003 and has since been incorporated into Council’s Development Control Plan No. 1. The Policy is designed to protect and, where possible, restore watercourses (both natural and modified) within the City to improve water quality and reduce run-off volume. A copy of the policy is available from Council.
There are several State laws that prevent the modification of streams, wetlands and waterways including: Environmental Planning and Assessment Act; NSW Fisheries Management Act; Water Management Act; and the Rivers and Foreshores Improvement Act.