Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.

Estuarine habitats, and in particular coastal floodplains and wetlands, provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally significant. Human activities on coastal land, such as those associated with grazing and intensive cropping or industrial and residential development, can have detrimental downstream effects. For fisheries production in the estuaries of northern NSW, two of these land-based activities, drainage of acid sulfate soils and the alienation of significant habitat areas, may have severe consequences.

These two issues were addressed in this research project, the findings from which will be used to restore degraded fish habitats and enhance access to them by fish, thereby improving fisheries in affected areas.  Ultimately, fishers, farmers and landholders will benefit from improved water quality in their drainage systems. The research findings will have specific implications for management of floodgates in those catchments studied and will be more generally applicable to acid sulfate soil catchments throughout NSW and Queensland.

Many coastal floodplains in Australia have an extensive network of floodgates, constructed drains and modified water courses. These are designed to mitigate the impacts of floods and large rainfall events. Floodgates prevent flood waters and tidal brackish water from inundating low areas of the floodplain. Constructed drains have converted prior wetlands into dryland farming areas. Whilst these developments have enhanced rural settlement and industries they have also caused unintended adverse impacts to fisheries, the ecology of estuaries and downstream water users.

The expanded drainage network has increased the generation and export of acidity from acid sulfate soils. Drainage systems can rapidly transfer acidity and deoxygenated water from backswamp areas to creeks and estuaries after rain. Floodgates and constructed drains have also blocked fish movement to upstream habitat areas and provide conditions that are conducive to the formation of poor water quality, particularly water with low dissolved oxygen.

These guidelines outline principles and strategies which can be employed to improve the environmental performance of coastal floodplain drainage systems, while retaining their benefits for agriculture. They have a particular focus on reducing drainage of acidity from areas with acid sulfate soils. The benefits, limitations and risks associated with management changes are described.