Great Sandy Straits
Everyone lives and works in a river catchment. Everything you do in your backyard, your school playground, your farm or your business then has the potential to affect waterways lower down the catchment,and ultimately the ocean and marine life.
Even little things you do in your part of the catchment can help prevent big problems like toxic algal blooms elsewhere in the system.
- What is a catchment?
- Catchment areas are important
- Toxic algal blooms
- You can help care for catchments
- What is government doing to protect water quality?
What is a catchment?
A catchment area or basin is land which is bounded by natural features such as hills or mountains from which all runoff water flows to a low point. This low point will be a dam, a location on a river, or the mouth of a river where the water enters a bay or the ocean.
It's just like water in a bathtub flowing to the plughole, or water that falls on a roof flowing to a downpipe.
Catchment areas vary in size and make-up. Large catchment areas such as those drained by the Burdekin and Fitzroy Rivers are bordered by mountain ranges and include major drainage networks of creeks and rivers. Large catchment areas are made up of hundreds of smaller 'sub-catchment' areas. These can be bordered by low hills and ridges and drained by only a small creek or gully.
Catchment areas are important
What happens in one part of a catchment is likely to affect the wellbeing of the rest of the catchment area, so there are many things you can do to minimise your impact on the system.
For example, since stormwater drains run straight into our waterways, heavy rainfall can wash sediments, rubbish and pollutants into the rivers and eventually into the ocean. This may impact negatively on aquatic life, coral reefs and seagrass beds. It can also affect people who use the water, for example, for irrigation or stock watering.
Development decisions under the Environmental Protection Act 1994 involving pollutant discharge to waterways must consider environmental values and water quality objectives.
The Environmental Protection (Water) Policy 1997 and the State Coastal Management Plan 2001 (urban stormwater) requires local governments to consider environmental values and water quality objectives for waters of the coastal zone when making environmental management decisions.
Well-known contaminants include oils, animal waste, litter, fertilisers and weed sprays. But grass cuttings, leaves and soil can also upset the waterways' ecological balance. Some pollutants directly poison aquatic and marine plants and animals; others harm the environment through eutrophication or sedimentation.
Floods and cyclones are natural processes which can benefit the environment. Changes we make to our catchments can change the way they respond to flooding and cyclones.
To better manage our natural assets to reduce harm from such natural disasters, the department has prepared:
- Natural assets for flood and cyclone resilience: Review of planning mechanisms used worldwide for mitigation of natural disasters using a natural assets approach
- Natural assets for flood and cyclone resilience: Synthesis of scientific evidence on the role of natural assets to reduce the human impacts of floods and cyclones
Toxic algal blooms
The blue-green algal blooms which have caused serious damage to many of our waterways in the last few years are a result of accelerated eutrophication.
Accelerated eutrophication occurs where excess nutrients make their way into inland and coastal waters, allowing increased growth of algae. As the algae decay they deplete the oxygen content of the water and aquatic animals die in large numbers. Urban sewage and runoff from agricultural land and stormwater drains are the major causes of these damaging algal blooms.
So, we need to think of our roads, yards, farms and drains in the same way we do our creeks, remembering all stormwater eventually flows into our waterways.
Sediments in waterways are particles of soils that have been washed from farms, construction and development sites, road stockpiles, sewage effluent and other sources.
Large amounts of sediments in the water reduces the amount of light able to reach the river beds and bay bottoms. That means aquatic plants and marine seagrasses don't have enough light to photosynthesise and die.
Sediments cause more problems as they sink to the bottom, because they alter the shape of estuaries and shores and smother filter-feeding marine life such as coral and sponges.
The combination of increased sediments and higher nutrients have been linked to massive dieback of seagrasses in many areas.
You can help care for catchments
You can do many little things such as reducing water pollution and conserving water to reduce your impact on your catchment. Minimising erosion around your home and business will also reduce problems downstream; tree planting and mulching prevents excess soil and nutrients getting into drains and creeks.
You can also help by joining your local Landcare or Waterwatch group and supporting programs that care for your catchment including programs being developed by your Regional Natural Resource Management Body.
Regional Natural Resource Management Bodies are a joint initiative between Queensland and Australian Governments. Queensland has 12 regional natural resource management bodies in 14 regions. These groups develop regional Natural Resource Management plans and organise on-ground works and community events.
Regional Natural Resource Management depends on local people and local communities getting involved. To get involved or to find out more about Regional Natural Resource Management Bodies follow the Regional Natural Resource Management link above.
What is government doing to protect water quality?
The Reef Water Quality Protection Plan is a joint initiative of the Queensland and Australian Governments. The goal of the plan is to halt and reverse the decline in water quality entering the Great Barrier Reef within 10 years.
Water quality entering the Great Barrier Reef lagoon is impacted by land sourced pollutants such as sediments, nutrients and chemicals entering reef catchment waterways.
The Reef Water Quality Protection Plan is focussed on ways to improve the quality of water, through improved farming and grazing practices, to reduce diffuse sediments and nutrients from entering the reef waterways.
Activities by industry, community groups and government agencies are underway to improve the quality of the water flowing into the Great Barrier Reef.
To get involved visit the Reef Water Quality Protection Plan website.
Marine parks are established over tidal lands and waters to protect and conserve special areas while allowing for the planned use of marine resources.
Special areas protected by marine parks conserve important natural features such as seagrass meadows, mangroves, rocky shores, reefs, sandy beaches, bays, sheltered channels, rivers, creeks and estuaries.
These areas are home to a wealth of wildlife including whales, turtles, dugong, grey nurse sharks, fish, corals, birds and more.
Marine parks protect our marine environments from the threat of direct impacts, including land sourced runoff of sediments, nutrients and chemicals as well as the careless discarding of litter.
We can improve the health of our marine environments by:
- disposing of all rubbish properly
- taking cans, glass, plastics, fishing line and non-biodegradable wastes ashore
- not discarding pollutants in stormwater drains
- reducing your use of chemicals, fertilisers and pesticides
Remember, what goes down your stormwater drain, sink and toilet or on your garden eventually reaches our marine environments.
Find out more about Queensland's Marine Parks.
The State Coastal Management Plan describes how the coastal zone is to be managed as required by the Coastal Protection and Management Act 1995. Water quality is amongst the topics addressed by policies for managing the major coastal zone issues. The policies and principles of The State Coastal Management Plan are to be applied at a regional level through the Regional coastal management plans.
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