Narrabeen Lagoon: Creating A Sustainable Catchment Project

 

 

 

Narrabeen Lagoon was given a new lease of life in 2007 with a $1.9million grant from the NSW Environmental Trust. The grant was awarded to Warringah and Pittwater Councils, the joint managers of the lagoon, for the ‘Narrabeen Lagoon – Creating a Sustainable Catchment’ project.

This project has been assisted by the New South Wales Government through its Environmental Trust.

The grant will be spent over three years on a catchment-wide sustainable living education program and on ground works such as creek bank remediation and bush regeneration at Middle, Mullet and Nareen Creeks.

Warringah Council, Pittwater Council and The Friends of Narrabeen Lagoon host community meetings every few months to update the community on the next steps being taken in the project.

Friends of Narrabeen Lagoon Catchment Inc Forum

Meeting the Challenge: How do schools, business and community

live sustainably in a catchment?

24 August 2009, 6.30 – 7.30 pm

Tramshed, Berry Reserve, Narrabeen

Valuable habitat

Narrabeen Lagoon was formed some 6,500 years ago when sea levels rose and stabilised, depositing the Collaroy-Narrabeen sand barrier. It is a valuable habitat, refuge and nursery for a diverse range of fauna and flora, including:

> vegetation communities

> birds

> mammals

> reptiles and frogs

In fact, the lagoon and surrounding area is an important stopover for migratory birds and is home to one third of the bird species that are represented in Sydney. Unfortunately, it has also been infested with weeds and feral animals.

The Lagoon and its foreshores are a natural wildlife corridor - a continuous area which allows wildlife to move through an urban environment. It forms part of the Green Link corridor which runs from Long Reef Headland, Dee Why Lagoon and South Creek to Warriewood Wetlands.

Other places of significance that lie within the boundaries of the Narrabeen Lagoon Catchment include Warriewood Wetlands, Garigal National Park, and Aboriginal heritage areas.

A biodiversity assessment and management plan of Middle Creek - a tributary of Narrabeen Lagoon - has been completed showing that the area supports a rich diversity of flora and fauna.

• Middle Creek Biodiversity Assessment and Management Plan (PDF, 5.8MB)
• Middle Creek report Appendices (PDF, 15.6MB)

What is a catchment?

A catchment is an area of land that collects water. Catchment boundaries are defined by hills and ridges. Water flows downward from roads, driveways and land into surrounding creeks, wetlands, lagoons and eventually the ocean.

The Narrabeen Lagoon catchment area is over 55 sq km. The land uses within the area are diverse. It accommodates residential premises, industry, nurseries, schools, shopping centres, retirement villages and golf courses, and is visited by more than 1,000 people every day for recreational purposes, each of which impact on the environment of the catchment.   

The quality of water draining from catchments is influenced by the land uses and associated activities taking place nearby. When it rains, the water runs through each of these areas then drains through stormwater pipes into one of the many creeks that leads downstream to Narrabeen Lagoon.  Any litter, debris (such as soil or leaves), soap, oil, or other chemicals that are on the ground are washed down the creek lines, eventually ending up in the lagoon and affecting the overall health and aesthetics of the flora and fauna in and around the area.

 

What affects water quality and catchment health?

Sedimentation: Soil erosion and topsoil disturbance may result in sediment entering the waterways within the catchment. When soil enters the water small particles make the water cloudy and murky which in turn may lead to fish and vegetation dying from restriction of light and oxygen supply.

 

Nutrient enrichment: Nutrients such as phosphorous and nitrogen encourage the growth of weeds and algae. Phosphorous and nitrogen are present in many household products and waste such as detergents, garden refuse, fertilisers, animal faeces, and sewage overflows. They can make their way into the environment inadvertently through washing cars on the street, dumping vegetative waste and failure to collect animal faeces. Excessive nutrients may cause an algal bloom, which reduces light penetration and dissolved oxygen in the waterway.

Weeds: Weeds and weed seeds are carried in water and soil. Frequently they are trapped in sediment where, aided by extra nutrients, they grow quickly. Weeds can take over bushland areas and waterways, restrict water flow regimes and reduce the habitat and diversity of native animals and plants.

 

Plant diseases: Infectious diseases in plants such as the fungus Phytophthora cinnamomi are easily transported and will quickly spread down slopes. This can occur through soil moisture, by creeks flows or runoff and when contaminated soil is transferred by tools, footwear, vehicles and bike tyres. When these diseases spread they attack native plants and often have very devastating consequences.

Oil and other chemicals: The Narrabeen Lagoon catchment is moderately urbanised and contains several major roadways, commercial and industrial premises - all of which are a potential source of oil and chemical spills. Oils and chemicals in the water are unsightly and at high concentrations are toxic, which may cause fish and plants to die.

More links about Narrabeen Lagoon:

• Activities
• Other Narrabeen Lagoon projects
• Narrabeen Lagoon Catchment Community Wildlife Survey results
• Feedback about our website

 

How you can help our catchment

• Plant local natives in your garden, those that occur naturally in the area (click on link for list of local native nurseries).
• Use native grasses for your lawn as they need less water than non-natives species and do not become weeds in local bushland.

• Avoid using chemical-based pesticides and fertilisers, especially before rain or next to creeks and waterways. Encourage natural pest controllers like blue-tongued lizards, leaf-tailed geckos and bandicoots into your garden by providing rocks and logs for them to live in.

• Dispose of garden waste through composting, mulching or recycling. Dumping weeds and grass clippings is against the law and spreads weeds through the catchment and increases algal outbreaks. 
• Use a broom to sweep up leaves from paved areas and guttering and use as mulch or compost.

• Install a rainwater tank at your home. It can store water from your roof to use on your garden and around the home. It also reduces the amount of stormwater going down our drains.

• Clean up after your dog.  Dog droppings add unwanted nutrients that change the soil to favour weeds over native plants.

• Recycle oils and chemicals. Spills can be absorbed with sawdust or sand and placed in a rubbish bin. Don’t put chemicals, oils or paint down the sink or drain.

• Washing your car responsibily. Park it on the grass and use a bucket, use car-washing products that don’t require water, or a carwash that uses recycled water.
• Keep rubbish out of the drain as it ends up in our local waters.
• Prevent root rot by washing soil from boots, tools and tyres to prevent the spread of Phytopthora cinnamomi, a fungus that causes root rot.
• Check driveway drainage and ensure it drains towards your garden. You will water your plants when it rains and save precious water loss down stormwater drains.
• Minimise hard surfaces such as paving, tiling, and concrete around your home. Wherever possible use of permeable paving, pebble paths, lawns and garden areas to keep water on your property.

Click on the links below for information about Narrabeen Lagoon's flora and fauna...

Vegetation communities	Birds	Mammals	Reptiles and  frogs
Fish and   macroinvertebrates	Weeds and feral animals	Surrounding areas	Narrabeen Lagoon activities