Wetlands and Water
Wetlands are areas permanently or periodically filled with water. Wetland types are categorised by the quantity and quality of water, how long water lies within the wetland, and how often it inundates or flows through the wetland.
The main classifications of wetland groups are: lacustrine wetlands (for example, deep, permanent freshwater lakes); palustrine wetlands (for example, shallow floodwater in swamps); riverine wetlands (for example, rivers that flow continuously — perennial, or rivers that flow occasionally — ephemeral); estuarine wetlands (for example, the downstream tidal end of rivers); and marine wetlands (for example, open coastal and marine waters).
Each type of wetland, and the plants and animals that depend on them, have evolved to suit the natural range of water quantity and water quality. Beyond these natural variations, wetlands can change in condition or nature, and this affects their values and uses.
When interpreting water quality, water quantity and water flow information (including the timing of the flows), it is important to consider the type of wetlands involved. This understanding helps detect variations beyond natural ranges and events for each wetland type.
For example, the wetland management profile for inland non-arid swamp wetlands explains that these wetlands are:
Subject to temporary but frequent inundation; that is, annually or in most years. Water in these wetlands is invariably fresh and is typically supplied by wet season (October to April) thunderstorms and/or monsoonal rains, via creeks or local run-off and in some cases by groundwater. By the mid to late dry season (for example, in August and September) the wetlands are dry, or are mostly shallow, but with some persistent deeper water.
If the water quantity and water quality to these wetlands changes — for example, by diverting or damming the water or by polluted stormwater run-off — it could change their condition and nature.
To maintain their health and values, wetlands rely on a natural water regime. This includes the quantity and quality of water, the length of time it remains in or flows through wetland, flow intensity and what time of the year these variations occur.
Management of wetlands, including the management of water quality and water quantity, should be considered on a whole-of-catchment basis. A number of Queensland programs and initiatives address planning and managing water quantity and water quality that affect wetlands
Water Quantity
Water resource planning
Water is one of the most fundamental and vital resources for the prosperity and wellbeing of all Queenslanders. It is also essential to the health of our wetlands.
However, water is not in endless supply and we must ensure that the health of our surface water and groundwater reserves are maintained so that we can provide for the needs of future generations.
Through the Water Act 2000 and water resource plans, the Queensland Government is striving for a correct balance so that everyone can continue to enjoy the benefits that flow from properly managed water resources and the ecosystems on which they depend. Complementary initiatives, such as the National Action Plan for Salinity and Water Quality and vegetation management planning, will also contribute to the health of our wetlands.
The Water Act enshrines in law for the first time the need for human water use — for example, for towns, industry, irrigation and mines — to make adequate provision for the natural processes that underpin wetland health.
The Water Act requires the preparation of water resource plans — and where necessary, resource operations plans — which ensure that water is equitably managed to preserve our quality of life and our aquatic ecosystems. A water resource plan details what the government aims to achieve for a catchment’s social, economic and environmental needs, while a resource operations plan details how water resources will be managed from day to day to meet these objectives.
Water allocation requirements of wetland systems
The water supplied to wetlands by natural events has been modified — to varying degrees in Queensland — by a range of human activities. These activities include river regulation, river diversion, excessive and prolonged inundation (for example, crop flooding), and excessive water abstraction of surface and groundwater supplies. This has led to the degradation or permanent change in nature of some wetlands.
The importance of water allocation requirements of wetlands systems has gained recognition in recent years. While many studies have focused on water allocation of rivers, they have been expanded to include other types of wetlands. These studies have investigated and developed methodologies to determine the special water allocation requirements of different wetland systems.
The following references provide more detailed information about the environmental water requirements of different wetland systems:
Freshwater related environmental management principles and guidelines
Environmental water requirements to maintain wetlands of national and international importance
Environmental water requirements to maintain estuarine processes
Environmental water requirements of groundwater dependent ecosystems
Protecting Australia’s rivers, wetlands and estuaries
Other water resource publications
Water Quality
Water quality in all wetland systems varies naturally due to natural factors (for example changes in climatic condition). It is also impacted by human activities such as land clearing, changes in land use, management practices and discharges of treated wastewater effluents. These impacts can adversely affect the wetland ecosystems, as well as the human uses and values of the wetlands (e.g. industrial, recreational, cultural).
Water Quality Management
The basic process for water quality management is:
- Assemble the current understanding of the wetland system (typically this includes compiling a conceptual model of the wetland system, showing its values and threats to these values)
- Establish the values (social, economic, ecological, cultural) of the wetlands in consultation with the relevant stakeholders and community
- Using the best available scientific guidelines for the established values, enumerate the water quality objectives / targets to protect these values
- Develop alternative management strategies to protect and improve water quality
- Assess the social, economic and environmental impacts of these strategies and, in consultation with stakeholders, agree on the priority strategies to be implemented
- Implement these strategies and monitor the actions implemented and the change in wetland condition
- Review/evaluate the monitoring data, report on it and, where necessary, make the necessary refinements in above components.
The above water quality management process / framework is embodied in the National Water Quality Management Strategy (and its associated documents) and in the Queensland Government’s water quality management activities under the Environmental Protection Act 1994 and the Environmental Protection (Water) Policy 1997.
The following references provide more detailed information about water quality management of wetland systems:
Established environmental values and water quality objectives
Water quality indicators
Queensland Water Quality Guidelines
Comparison of water quality data with guidelines
Water quality monitoring
Other water related links
Last updated: 4 July 2008
