Water resources - Overview - New South Wales
Basin & Surface Water Management Area: Macleay River
Introduction
The Macleay catchment of some 11500 square kilometres includes extensive areas of the Northern tablelands, a sparsely populated escarpment area and a coastal area ranging from foothills to coastal plans. From the gently rolling hills of the tablelands, the central catchment is mountainous with deep gorges. The lower catchment consists of wide floodplains extending to the coast and includes Kempsey and South West Rocks.
Major centres include Armidale, Walcha, Guyra, Kempsey and the population of the subcatchment is estimated at 60,000.
The climate varies from temperate on the coast to cool temperate on the tablelands, while the annual average rainfall varies from 1,840 mm on the coast to 600 mm on the tablelands. Soils in the upper catchment vary from red and yellow podzolics to krasnozems. In the steep middle catchment shallow lithosols, stony red or yellow earths and stony duplex soils are found. The Macleay floodplain consists of mainly alluvial soils.
Much of the tablelands has been cleared of trees and is now covered in native and introduced pastures. Rainforest and wet sclerophyll forests occur in the steep slopes and gorges of the escarpment. The lower ridges support wet and dry sclerophyll forests. These give way to cleared pasture land and wetlands on the floodplain. Coastal vegetation consists of grasses, shrubs and trees on the dunal system.
Natural resource issues range from New England Dieback, dryland salinity and soil degradation to acid sulphate soils, streambank erosion and fish habitat destruction.
Vital Statistics:
| Area: | 11,420 Km2 |
|---|---|
| Total storage volume: | 25,556 |
| Total surface water use: | 0 ML/yr |
| Development category: | MEDIUM DEVELOPMENT |
| Mean annual run-off: | 1,950,000 ML/yr |
Please note: No data were supplied about total surface water use for some river basins (eg. unregulated basins in NSW).
A four-class classification system was developed to provide a simple method to communicate the status of the use and allocation of Australia's water resources in relation to sustainable water management.
It is important to recognise that adequately quantifying a sustainable flow regime or sustainable yield and consequent operating rules is a complex matter. State, Territory and scientific agencies continue to develop and apply methods and measures for determining sustainable flow regimes and sustainable yields.
This categorisation provides a general guide only. Please refer to the State and Territory Overview and Technical reports for detail on the analysis methods used.
| Category | Development status | ||
|---|---|---|---|
| 1 | <30% | Low development | |
| 2 | 30 - 70% | Moderate development | |
| 3 | 70 - 100% | Highly developed | |
| 4 | 100% | Overdeveloped |
* Water use as a percentage of sustainable flow regime (surface water) and sustainable yield (groundwater)
PLEASE NOTE:
Sustainable Yield:
NSW is introducing volumetric licenses for the management of unregulated valleys and is currently collecting a wide range of data in unregulated basin.
The sustainable yield concept, ie the amount of water that can be diverted from rivers in perpetuity, is recognised in NSW. However NSW's current management practices views the sustainable yield as an allowable daily extraction volume as opposed to an annual yield figure. As well future reviews of the performance of the management rules to be adopted in each valley plus additional knowledge at that time may result in changes to the rules and hence changes to the "Sustainable Yield".
NSW has taken the approach that it is better to await the availability of data on the unregulated basins based on reliable and realistic analysis than to divert limited resources from this process to provide data based on unreliable information and inappropriate analysis. Accordingly the Sustainable Yield has not been calculated for the unregulated basins in NSW.
However an attempt was made to obtain a categorisation for the catchment based on the work done for the stressed streams.
A variable P was determined for the total catchment on the basis of the combined stress classsification results from the stressed streams analysis where P = (Total area of sub-catchments with high combined stress / Total area of classsified sub- catchments in basin)
Categorisation was on the basis that:
Category 1 applies for 0% <= P < 30% Category 2 applies for 30% <= P < 70% Category 3 applies for 70% <= P <100% Category 4 applies for P = 100%
Please refer to the attached Stressed Rivers Report(s) from the NSW Department of Land and Water Conservation's website for further information about this basin.
PLEASE NOTE:
Categorisation:
NSW is introducing volumetric licenses for the management of unregulated valleys and is currently collecting a wide range of data in unregulated basin.
The sustainable yield concept, ie the amount of water that can be diverted from rivers in perpetuity, is recognised in NSW. However NSW's current management practices views the sustainable yield as an allowable daily extraction volume as opposed to an annual yield figure. As well future reviews of the performance of the management rules to be adopted in each valley plus additional knowledge at that time may result in changes to the rules and hence changes to the "Sustainable Yield".
NSW has taken the approach that it is better to await the availability of data on the unregulated basins based on reliable and realistic analysis than to divert limited resources from this process to provide data based on unreliable information and inappropriate analysis. Accordingly the Sustainable Yield has not been calculated for the unregulated basins in NSW.
Please refer to the attached Stressed Rivers Report(s) the NSW Department of Land and Water Conservation's website www.dlwc.nsw.gov.au for further information about the Macleay Basin.
How saline are the surface water resources in the Macleay River surface water management area?
No data were available about the salinity of surface water resources in the Basin / SWMA for the Australian Water Resources Assessment 2000.
Major water storages
Table: Major water storage areas:
| Storage name: | Capacity (ML) |
|---|---|
| Williams | 600 |
| Dumaresq Dam | 440 |
| Guyra No.2 Dam | 375 |
| Gara River Dam No 1 | no data |
| Malpas Dam - Black Mountain | 13,000 |
| Gara Dam | 270 |
| Guyra No.1 Dam | 91 |
| Commissioners Waters. | no data |
| Dutton Hatchery Weir | no data |
| Gara River Dam No 2 | no data |
| Hickeys Creek Weir No. 1 | no data |
| Hickeys Creek Weir No.2 | no data |
| Mungay Creek Weir No 6 | no data |
| Mann River | 3,400 |
| Mungay Creek Weir No 8 | no data |
| Ohio Creek Dam No 1 | no data |
| Ohio Creek Dam No 3 | no data |
| Oaky River Power Station Dam | 2,780 |
| Broombee | 1,700 |
| Puddledock Reservoir | 1,700 |
| Lake Tullimba | 1,200 |
| Total | 25,556 |
Further Information
- View the New South Wales Water Resources Assessment 2000 Report
- View the New South Wales Water Resources Assessment 2000 Technical Report
- Link to data available for download on the:
- Surface Water Management Areas
- Data from the 1985 Review of Australia's Water Resources and Water Use
- Link to the Map Maker to make a map using this information.
- For more information about water and other natural resource issues link to www.dlwc.nsw.gov.au.
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