logo Water resources on the south coast April 2001


This summary of south coast water resources is based on various reports and information available from the Department of Environment in Albany. A bibliography at the end of the document lists additional reading for anybody interested in further reading, but as knowledge of water resources is changing constantly, readers are encouraged to contact the Department of Environment with any detailed enquires on water resource issues.

The term water resources is used to describe all groundwater and surface waters along the coastal area, but does not include marine waters. Wetlands, estuaries, rivers and creeks are all water resources that are in part managed by the Department of Environment, along with other agencies. The department has a general duty to protect potable (drinking water) supplies.


To the casual visitor water resources on the south coast of Western Australia are in a relatively pristine condition. The beauty of the numerous estuaries, inlets, major rivers and wetlands is often remarked upon, and brings appreciation and repeat visits from travellers.

Residents of the south coast appreciate the beauty of these areas, and also understand the economic value of these resources. But residents are also aware these resources are under threat, from increased development, inappropriate land uses and land clearing. Sedimentation, algae blooms, fish kills, increased salinity, pollution events, destruction of foreshore vegetation, infilling of wetlands and reclamation of estuaries are very visual examples of the pressure being placed on water resources in the region.

Our knowledge of water resources is far from perfect. While some estuaries or groundwater areas receive much research and are well understood, others have little information available. Establishing priorities for action across the south coast needs to recognise this shortfall in information.

Potable surface water

The use of surface water for drinking purposes is mainly confined to the western part of the south coast region. Denmark's water supply is provided by tributaries of the Denmark River, which are largely confined within State Forest. The Quickup Dam supplies the vast majority of this water. The Angove River to the east of Albany supplies the Lower Great Southern Town Water Supply, which caters for Albany, Mt Barker and Narrikup drinking water. The river supplies nearly a third of Albany's reticulated water.

Potable surface water supplies are limited away from the coast, as water quality is generally too saline or of insufficient supply. The exception is Bolganup Creek which has been dammed to provide water for Porongurup and Mt Barker. The creek's water quality is maintained due to its catchment being entirely within the Porongurup National Park.

The Albany-Denmark region has various rivers and creeks that offer possibilities for future potable water supplies. They include the Kent and Denmark rivers, which are included as Water Resource Recovery Catchments in the Government's Salinity Action Plan. The plan hopes to reduce salinity in these catchments so that they can be used for drinking water purposes by the years 2030 and 2020, respectively. Other options for future potable water include a number of small coastal creeks, such as the Goodga river. The Water Corporation is presently assessing the suitability of using Marbellup Creek as a future water supply. The Marbellup catchment is already declared a water reserve under the Country Areas Water Supply Act.

The utilisation of coastal creeks for potable water could have a number of environmental impacts, caused by the reduction in downstream flows and through the construction of dams or pipeheads. The protection of these water supplies also has important impacts on the suitability of development in these catchments.

The consideration of present and future potable surface water supplies is covered in more detail in the Albany-Denmark Region and Esperance Region Water Resources Reviews and Development Plans, both prepared by the Water and Rivers Commission in 1997. See the bibliography for more details.


The south coast region has a unique and diverse range of wetlands that occupy a large proportion of the landscape and are critical components in the regional ecology. Changes to the hydrological regime, caused by clearing, rising groundwater and altered drainage lines, are a serious threat to many of these wetland systems. Commonly, wetland vegetation is being lost through increased inundation and salinity.

A regional classification of wetlands has been recently completed that identifies significant wetland suites and their potential threats. Seventeen outstanding wetland systems have been identified that are of national or international significance. These include the Ramsar listed Warden System and the potential Ramsar site of Lake Gore (list pending). There are also another 77 wetland systems that have been identified as of state or regional significance. The identification and classification of these wetlands provides the basis for improved management and understanding of these important systems.

Generalised condition of wetland systems in the south coast region

Name Significance Conservation category Fringing vegetation Hydrological regime Salinity
Balicup Lake System N C A Modified Hypersaline
Lake Gore System R C B Significantly altered Saline
Lake Warden System R C C Significantly altered Hypersaline
Howick Lake W C B Modified
Monjingup Lake W C B Modified Fresh
Benje Benjenup Lake W C C Modified Hypersaline
Mortijinup Lake System N C A Modified Saline
Pink Lake N C C Modified Hypersaline
Coomalbidgup Swamp W C B Significantly altered Fresh
Roberts Swamp W C B Modified Brackish
Coujinup Swamp W C B

Lake Chidnup W C B Modified Brackish
Yellilup Yate Swamp System
(Pabelup, Cordinup and Marendiup suites)
N C B Significantly altered Brackish
Lake Muir
(Muir-Unicup Suite)
N C B Significantly altered Marginal
Lake Pleasant View System
(Corimup Suite)
N C B Modified Fresh
Stokes Inlet System W C A Modified Saline
Peak Charles System W C A Modified Saline
Owingup Swamp Suite N C A Modified Fresh
Kojaneerup Suite W C A Natural Saline
Manypeaks Suite W C B Modified Fresh
Lake Saide Suite W R C Modified Fresh
Frenchman Bay Suite W C B Natural Fresh
Lake Seppings Suite W R C Modified Fresh
Jerdacuttup Lakes System W C B Modified
Lake Shaster System W C A Natural
Kent Lakes
(Unicup Suite)
W C-R B Modified Fresh-Saline
Lake Matilda W R C Significantly altered Saline
Pardelup Lagoon W C B Modified Fresh
Mills Lake System W R D Significantly altered Marginal
Goode Beach Suite W C A Natural Fresh
Gull Rock Suite W C A Natural Fresh
Gardner Lake Suite W C A Natural Fresh
Moates Lake Suite N C A Natural Fresh

Fringing vegetation A: Wetland in national park, nature reserve or State Forest.
B: Wetland in small reserve or large block of remnant vegetation.
C: Some remnant vegetation connected to the wetland.
D: Wetland surrounded by cleared land
Hydrological regime Natural: Natural hydrological regime, wetland fully functioning.
Modified: (for example due to stormwater or rural drainage discharge, clearing, abstraction of groundwater or surface water etc). Generally wetland remains healthy.
Significantly altered: Wetland hydrology significantly altered, resulting in impacts upon wetland health (tree deaths, changes in vegetation composition, loss of habitat)
Significance R: Wetland of international importance nominated for inclusion under the Ramsar Convention
N: Wetland included in "A Directory of Important Wetlands in Australia" (Australian Nature Conservation Agency, 1996)
W: Regionally significant wetland, as identified in a regional study
Conservation category C: Conservation wetlands: Wetlands recognised at the international, national or regional levels; High Conservation and Conservation wetlands identified using Bulletin 374 assessment; wetlands 95-100% undisturbed, vegetated sections of extensive wetlands.
R: Resource Enhancement: Wetlands 20-94% vegetated and Bulleting 374 Resource Enhancement and Open Space wetlands not defined as Classification C.

Many of the more valuable wetlands are located just inland of the region's coastal dunal system. These wetlands receive higher levels of rainfall and are often protected through inclusion in national parks or reserves. These wetlands are less modified by development or by changed water levels or salinity. Further inland wetlands have been affected by land clearing, rising groundwater levels and salinity. Some wetlands have also been modified by drainage.

Nutrient enrichment of wetlands is also common on the south coast, and this may create increased problems with midges and harmful algae blooms. Modified wetlands may still have a valuable conservation function, as is the case with Lake Powell located between Albany and Denmark. This lake is a nature reserve and an important habitat for wading birds, but its also suffering from blue-green algae blooms caused by changes in flows through drainage works and in past discharges of treated effluent.

Further details of south coast wetland types, location and management issues can be found in reports undertaken by V. and C. Semeniuk Research Group (see bibliography).


The general condition of major river systems of the south coast has been assessed and some information is summarised in the table below. Major rivers in the east of the region are naturally brackish to saline however salinity levels are elevated due to clearing. Rivers to the west are mainly fresh to brackish due to the higher rainfall, although increased salinity is also apparent in major western rivers where headwaters drain heavily cleared saline lands. Loss of vegetation due to salinisation, clearing and grazing has resulted in erosion and sedimentation in many rivers and tributaries.

A survey of major rivers using remote sensing shows that there are reaches that have riparian vegetation in good condition although many of these reaches occur in parks and reserves. Several rivers and tributaries have now been surveyed in detail to examine foreshore and channel condition and to provide management recommendations. While considerable work has already been undertaken, fencing and revegetation of riparian zones continues to be a priority for most waterways in agricultural areas.

Several river systems in the south coast suffer from increased nutrient levels. The Wilson Inlet catchment, drained by the Denmark, Hay and Sleeman rivers, is one of four national Focal Catchments under the National Eutrophication Management Program.

Generalised condition of major river systems in the south coast region

River Nutrients Erosion/sedimentation Fringing vegetation Salinity Flood risk
Tributaries to Lake Warden Very High Poor Poor Saline Medium
Lort and Young River Moderate Poor Moderate Saline Low
Oldfield River High Moderate Moderate Saline Low
Phillips River Moderate Poor Moderate Saline Low
Hamersley River

Excellent Saline Low
Fitzgerald River Low
Excellent Saline Low
Gairdner River Very High Poor Moderate Saline Low
Bremer River Moderate Poor Moderate Brackish Low
Pallinup River Moderate Poor Poor Saline Low
Kalgan River Low Moderate Moderate Brackish Medium
King River Moderate Moderate Moderate Fresh Medium
Torbay Drainage System High Poor Poor Marginal Medium
Sleeman Cuppup Drainage System High Poor Poor Marginal Medium
Hay River Low Poor Moderate Brackish Medium
Denmark River Low Moderate Moderate Marginal Medium
Scotsdale Brook Low Moderate Moderate Fresh Low
Mitchell River Low Excellent Excellent Fresh Low
Kent River Moderate Poor Moderate Brackish Low
Bow River Very High Moderate Moderate Fresh Low
Gordon River Very High Poor Poor Saline Medium
Frankland River Low Moderate Moderate Brackish Low
Deep River Low Excellent Excellent Fresh Low

Salinity Fresh: 0 - 500 mg/litre
Marginal: 500 - 1000 mg/litre
Brackish: 1000 - 5000 mg/litre
Saline: 5000 - 35000 mg/litre
Hypersaline: >35000 mg/litre
( Total N or Total P)
Extreme: > 4.0 mg/litre or > 0.5 mg/litre
Very High: 3 - 4 mg/litre or 0.3 - 0.5 mg/litre
High: 2 - 3 mg/litre or 0.2 - 0.3 mg/litre
Moderate: 1 - 2 mg/litre or 0.1 - .02 mg/litre
Low: <1 mg/litre or < 0.1 mg/litre
Fringing vegetation Excellent:Riparian corridor is largely intact, with possibly some small areas of degradation
Moderate: Balance between intact riparian vegetation and moderately affected areas
Poor: Largely cleared with land in private ownership for full length
Erosion/sedimentation Excellent:No evidence of sedimentation
Moderate: Some evidence of increased sedimentation
Poor: River pools largely filled with sediment or significantly enhanced sedimentation in estuary
Flood risk High:High probability with high consequences
Medium: Low probability with high consequences or high probability with low consequences
Low: Low probability with low consequences

Despite these problems the region's rivers provide important economic and environmental functions. The tidal reaches of major rivers such as the Denmark, King and Kalgan provide varied recreational opportunities and are important fish nurseries. The small coastal creeks are mainly fresh and provide habitat for fish species often not found elsewhere, and even the more occasional flowing rivers in the east of the region leave permanent ponds which provide year round aquatic habitats.


There are over 25 estuaries in the south coast region. Few are permanently open to the ocean and most range from being open annually (or more often during times of high catchment flows) to those that open infrequently and only during extreme events (maybe every ten years or more). Estuaries on the south coast are recognised internationally for their environmental significance and many are protected in reserves. They are also highly significant to the tourism, aquaculture and fishing industries.

In general, estuaries along the south coast are suffering from nutrient enrichment and sedimentation. Estuaries are the receiving bodies for water, nutrients and pollutants from the catchments and so ensuring their good health relies on good catchment management throughout the whole of the south coast region.

Generalised condition of estuaries in the south coast region

Estuary Nutrients Erosion/sedimentation Fringing vegetation
Stokes Inlet Moderate Excellent Excellent
Oldfield Estuary Moderate Excellent Excellent
Culham Inlet Moderate Poor Moderate
Hamersley Inlet High Excellent Excellent
Dempster Inlet

Fitzgerald Inlet

Saint Mary Very High Excellent Excellent
Gordon Inlet High Excellent Moderate
Wellstead High
Beaufort Inlet High Poor Excellent
Cheyne Inlet Moderate
and other minor estuaries east of Albany

Moderate Moderate
Excellent Excellent
Norman's Low Excellent Moderate
Taylor Inlet Low
Oyster Harbour Low Moderate Moderate
Princess Royal Harbour Low Excellent Poor
King George Sound Low Excellent Excellent
Torbay Inlet Moderate Poor Moderate
Wilson Inlet Low Poor Moderate
Parry Inlet Moderate
Irwin Inlet Low
Nornalup-Walpole Inlet Low Excellent Excellent

In the recently prepared National Land and Water Resources Audit only two estuaries on the south coast are considered 'near pristine', these being the Oldfield Estuary and Broke Inlet. Other estuaries or inlets have valuable and sometimes unique characteristics. For example, Waychinicup Inlet is unique in being the only river gorge flooded by the ocean along the south west coast. Oyster Harbour is permanently open to the sea and provides a regionally significant fish nursery. Princess Royal Harbour and King George Sound provide safe anchorage for the port of Albany. Nornalup Inlet has near pristine karri and tingle forrest heath and sedgelands extending to the edge of the inlet, and is located within the Walpole-Nornalup Park. All the estuaries and inlets on the south coast offer recreational opportunities, often of a wilderness type experience.


Hydrogeology and Potable Water

Albany-Denmark Region Water Resources Review and Development Plan April 1997. Vol 1 of 11. WRC Report WRAP2 1997.

Esperance Region Water Resources Review and Development Plan February 1997 Water and Rivers Commission Report WRAP5 1997.

Hydrogeology of the Mt Barker-Albany 1:250 000 sheet. Water and Rivers Commission Report HM1 1997

Hydrogeology of the Esperance-Mondrain Island 1:250 000 sheet. Water and Rivers Commission Report HM2 1998

Hydrogeology of the Ravensthorpe 1:250 000 sheet. Water and Rivers Commission Report HM4 1998


Preliminary delineation of consanguineous wetland suites between Walpole and Fitgerald Inlet, South Western Australia. V and C Semeniuk Research Group. Water and Rivers Commission June 1998.

A preliminary evaluation of wetlands in the Esperance Water Resource Region Ecologia Water and River Commission Nov 1999 (Draft)


Estuaries and coastal lagoons of South Western Australia. Environmental Protection Authority Perth W.A.

Estuaries of the Denmark Shire. Estuarine Studies Series Number 3 August 1988.

Estuaries of the Jerramungup Shire. Estuarine Studies Series Number 4 November 1988.

Estuaries of the Shire of Manjimup. Estuarine Studies Series Number 6 September 1989.

Estuaries of the Shire of Albany. Estuarine Studies Series Number 8 November 1990.

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