The condition of waterways and wetlands has been assessed within 14 waterways systems. The table below presents the trend and current condition for each of seven key values in each waterways system. The condition assessments were undertaken by Melbourne Water in developing the Healthy Waterways Strategy.
Across the region condition is greatest in the forested upper catchments and declines significantly once the waterways pass through agricultural and then urban landscapes. Waterways in the poorest condition occur where the natural rivers, streams and creeks have been modified into channels and drains.
Werribee & Little River Middle & Upper system
Current condition of the Werribee & Little River Middle & Upper system | |||
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Key value | Trend | Condition | Comment |
Platypus | Declining | Very low | Platypus populations have declined significantly in the past 200 years. Platypus have been sighted in this system but due to a lack of captures in recent surveys, the status of platypus populations is considered to be very low. |
Fish | Improving | High | The variety and proportion of native fish species is high. |
Frogs | Declining | Moderate | The variety of frog species appears to have declined since the 1990s. |
Birds | Declining | Low | With limited data, the condition of water-dependent bird populations is rated as low. |
Vegetation | Improving | Moderate | Vegetation in the upper reaches is intact and in moderate condition, but quality declines in lower reaches. Overall the vegetation is rated as moderate. |
Macro- invertebrates | Stable | Moderate | The condition of macroinvertebrate populations is moderate. |
Amenity | n/a | Moderate | Amenity is rated as moderate. |
Werribee & Little River Lowlands system
Current condition of Werribee and Little River Lowlands system | |||
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Key value | Trend | Condition | Comment |
Platypus | Declining | Very low | Platypus condition is low and recent monitoring shows that the recent drought has resulted in further declines. |
Fish | n/a | High | The condition of fish communities is high with a large variety of native fish recorded. |
Frogs | n/a | Moderate | The diversity of frog species is moderate. |
Birds | Declining | High | The variety and proportion of native birds is high, particularly at the Western Treatment Plant. |
Vegetation | Declining | Low | The condition of vegetation is predominantly low to moderate, but areas of high quality are found towards the upper reaches of Little River. |
Macro-invertebrates | Stable | Moderate | Macroinvertebrates condition is rated moderate. |
Amenity | n/a | Moderate | Amenity condition in this system is moderate, but a high condition is expected in the next 20 years as urban development occurs – increasing the opportunities for access – and the vegetation condition is improved. |
Cherry, Kororoit, Laverton & Skeleton system
Current condition of the Cherry, Kororoit, Laverton and Skeleton system | |||
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Key value | Trend | Condition | Comment |
Platypus | n/a | n/a | No platypus populations are found in this system, and there is little suitable habitat for them. It is unclear when the population would have disappeared, and no reliable catches have been recorded in the monitoring program which began is 1995. |
Fish | n/a | Moderate | The condition of fish populations is moderate. |
Frogs | Improving | High | The diversity of frog species is high. |
Birds | Stable | Low | The variety and abundance of native birds is low for streamside birds and high for wetland birds, with a low score overall. |
Vegetation | Improving | Low | Vegetation condition is predominantly low. |
Macro-invertebrates | Stable | Low | Macroinvertebrate condition is low. |
Amenity | n/a | Moderate | Amenity condition in this system is moderate but a high condition is expected as urban development occurs – increasing the opportunities for access – and the vegetation condition is improved. |
Upper Maribyrnong system
Condition of the Upper Maribyrnong system | |||
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Key value | Trend | Condition | Comment |
Platypus | Declining | Very low | Platypus populations have declined significantly throughout the catchment since the early monitoring period (1998). The small population of platypus in the Upper Maribyrnong system is considered to be very vulnerable. |
Fish | Stable | Moderate | Since the 1990s, fish populations have remained fairly stable, with a slight increase in diversity offset by declines in proportion of native fish. Currently a diverse population of fish can be found, however the proportion of native fish is moderate. |
Frogs | Declining | High | The diversity of frogs is high. While historic data is limited, a decline in the types of frogs appears to have been as recent as the 1990s. |
Birds | Stable | Low | Streamside birds data indicate that the abundance and diversity of waterway-dependent birds is low. |
Vegetation | Improving | Low | Most streamside vegetation is considered to be very low to moderate quality, however several small areas, mostly in the hilly headwaters, are rated as very high. |
Macro-invertebrates | Stable | Moderate | Macroinvertebrate condition has remainded stable since the 1990s. The condition of macroinvertebrate populations vary, with the highest being in forested waterways. |
Amenity | n/a | Moderate | Amenity will improve in key areas as natural vegetation along waterways is established. |
Lower Maribyrning system
Condition of the Lower Maribyrnong system | |||
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Key value | Trend | Condition | Comment |
Platypus | Declining | Very low | Platypus are recorded in very low numbers and considered to be at high risk of extinctions. Significant improvement in conditions, including flows and habitat, is required to ensure the survival of the population. |
Fish | Stable | Low | The number of fish species and ratio of native species is low; the condition score has remainded stable since the 1990s. |
Frogs | n/a | Low | The number of frog species is low. |
Birds | Declining | Low | Data on birds in this system is limited to streamside birds, but indicate that the population is in moderate condition, with a small but not significant improvement since the 1990s. |
Vegetation | Declining | Low | The condition of native vegetation is very low although some areas of remnant vegetation occur scattered along Maribyrnong River and Jacksons Creek, particularly in the Organ Pipes National Park and Sydenham Park. |
Macro-invertebrates | Stable | Moderate | Macroinvertebrate condition is moderate. |
Amenity | n/a | Low | The amenity enjoyed from waterways across the catchment is low. |
Upper Yarra system
Condition of the Upper Yarra system | |||
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Key value | Trend | Condition | Comment |
Platypus | Declining | Very low | Platypus populations have declined over the past decade, which is attributed to the long drought. However, platypus populations are still relatively large and so sightings of platypus in the upper tributaries are common. |
Fish | Stable | Moderate | Fish populations have declined, in numbers and diversity, over the past 200 years. However, a large number of native species occur and populations have been stable over the past 10 years. The decline is largely due to introduced fish preying on native fish. |
Frogs | n/a | Moderate | Investigations to determine the diversity of frog populations are limited, but the current rating is moderate and works over the next 20 years aim to increase this condition to high. |
Birds | Stable | Very high | The high quality of vegetation and a long history of habitat protection have allowed the condition of bird populations to remain very high. |
Vegetation | Improving | High | Much of the native vegetation is protected within public land and is of very high quality with minimal weed invasion. |
Macro-invertebrates | Stable | High | Macroinvertebrate populations are generally high due to the high quality of vegetation and water. Improvements to vegetation and water quality through continued protection of this system aim to improve macroinvertebrate condition to very high. |
Amenity | n/a | Very high | The management of public land means it has retained many natural features. Very high amenity is still enjoyed through natural forests, picnic areas at the dams, and views along the waterway corridors. |
Middle Yarra system
Condition of the Middle Yarra system | |||
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Key value | Trend | Condition | Comment |
Platypus | Declining | Very low | The past decade of drought has seen platypus numbers reduce from the 1990’s. Platypus populations in the middle Yarra are still common although population sizes are smaller than those found in the Upper Yarra. The population at Diamond Creek has increased in response to sucessful restoration works such as removing willows, stabilising the stream banks and replanting streamside vegetation. |
Fish | Stable | Moderate | Native freshwater fish species recorded in this system have been stable over the past decade, with introduced fish widespread. |
Frogs | Stable | Very high | The diversity of frog populations is very high and stable. |
Birds | Stable | Low | Extensive vegetation clearing has ocurred, which is reflected in the low condition of bird populations. These populations appear to be stable from the 1990’s. |
Vegetation | Improving | Moderate | A significant decline in the condition of vegetation has ocurred over the past 100 years, due to extensive clearing for rural and urban development. However this trend has reversed in the last 10 years. The quality of vegetation is rated moderate to low. |
Macro-invertebrates | Stable | Moderate | The condition of macroinvertebrate communities is highly dependant on the quality of water in the system. Rural and urban development has lead to a decline in water quality and macroinvertebrate condition is moderate. |
Amenity | n/a | Low | Many areas provide high amenity through intact streamside vegetation, natural waterway features and parkland where relaxation can occur, but the average score is low. Continued work on linking vegetated areas will improve the amenity. |
Lower Yarra system
Condition of the lower yarra system | |||
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Key value | Trend | Condition | Comment |
Platypus | Declining | Very low | Platypus habitat has been significantly altered by the impacts of urban development. Platypus population sizes have declined since 1990, possibly due to the effects of reduced flows. Platypus are now rare, however medium-sized populations are found in some urban sections of the Yarra river and tributaries. |
Fish | Declining | Moderate | A decline in the variety and proportion of native fish species has ocurred since the 1990’s. There is a moderate variety of fish species, and introduced species are reletavily abundant. |
Frogs | Stable | Very high | A decline in the variety and proportion of native fish species has ocurred since the 1990’s. There is a moderate variety of fish species, and introduced species are relatively abundant. |
Birds | Stable | Low | Urban development has been substantial and the condition of bird populations is rated as low. |
Vegetation | Improving | Very low | Extensive clearing of vegetation, due to urban development, has occurred over the past 200 years. Consequently, streamside vegetation quality is rated as very low. |
Macro-invertebrates | Stable | Low | Urban development and poor water quality have affected macroinvertebrate communities, and their condition is low. |
Amenity | n/a | Moderate | The amenity enjoyed from waterways is moderate, with specific areas providing important areas for relaxation and rejuvination. |
Dandenong system
Condition of the Dandenong system | |||
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Key value | Trend | Condition | Comment |
Platypus | Declining | Very low | Platypus populations have declined since the 1990s, likely due to the drought. Platypus are found in several locations in the upper catchment (Dobsons and Monbulk Creeks), but population sizes are small and considered to be at high risk of extinction. |
Fish | Stable | High | The diversity of fish species is high. Most fish are found in the lower Dandenong system. Several migratory species have been recorded in the upper region, which indicates that despite some physical obstacles in the waterways, some migratory fish are able to move from the lower to the upper region. |
Frogs | n/a | Very high | The diversity of frogs is very high. |
Birds | Improving | High | The diversity of bird species has increased slightly since the 1990s. The number and proportion of native birds is high. |
Vegetation | Improving | Very low | The upper reaches have some very high quality and intact vegetation. Many lower sections have much lower quality and overall vegetation is in very low condition. |
Macro-invertebrates | Declining | Low | Macroinvertebrates are in low condition. |
Amenity | n/a | Moderate | The amenity enjoyed from waterways varies widely. |
Upper Bunyip & Tarago system
Condition of the Upper Bunyip & Tarago system | |||
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Key values | Trend | Condition | Comment |
Platypus | Declining | Very low | The Lower Tarago River has the highest known abundance of platypus in the Western Port Catchment, but platypus populations have declined significantly over the past 200 years. The recent prolonged drought is considered a key reason for the recorded decline in that period. The population condition is rated as very low. |
Fish | Improving | Very high | The variety and proportion of native fish is very high. |
Frogs | Stable | Moderate | The diversity of frog populations is moderate, and has been consistent over the past decade. |
Birds | n/a | Moderate | Based on streamside birds, the variety and proportion of native bird species is moderate. |
Vegetation | Improving | Moderate | The upper reaches of waterways are largely within State parks, with vegetation condition declining in lower reaches. |
Macro-invertebrates | Stable | High | The condition of macroinvertebrate populations is high on forest reaches, with some decline in rural sections. |
Amenity | n/a | High | High amenity values are still provided and reserved through natural forests, picnic areas along rivers, and streams and vistas along waterway corridors. |
Lower Bunyip, Lang Lang & Bass system
Condition of the Lower Bunyip, Lang Lang & Bass system | |||
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Key values | Trend | Condition | Comment |
Platypus | Declining | Very low | A decline in platypus numbers has occurred due to significant alteration and disturbance of waterways. The population of platypus in Lang Lang River is small and following many years of drought, numbers are considered to be critically low. |
Fish | Declining | High | The condition of fish is high. |
Frogs | n/a | Very high | Frog diversity is very high. |
Birds | n/a | Very low | Bird condition is based on streamside birds only. The number and variety of species is very low. |
Vegetation | Improving | Very low | Vegetation has been subject to widespread clearing and condition is very low. |
Macro-invertebrates | Stable | Moderate | Macroinvertebrate condition is moderate. |
Amenity | n/a | Low | Some waterways have been dramatically altered and amenity is low. |
Cardinia system
Condition of the Cardinia system | |||
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Key values | Trend | Condition | Comment |
Platypus | n/a | Very low | Platypus became locally extinct in the late 1990s. Ten platypus were released into Cardinia Creek in 2004 and 2007 and have been recorded breeding. |
Fish | Declining | High | The condition of fish populations is currently rated as high. |
Frogs | n/a | Very high | The variety of frog species is very high. |
Birds | Declining | Very low | Monitoring since the 1990s indicates that the recent drought has resulted in a decline in native bird communities, which are in very low condition. |
Vegetation | Improving | Low | The condition of vegetation is low although the upper reaches of Cardinia Creek contain some relatively intact vegetation. |
Macro-invertebrates | Stable | Moderate | The condition of macroinvertebrate populations is moderate. |
Amenity | n/a | Moderate | There is limited data to assess the perceived condition of amenity, which is rated moderate. |
Mornington Peninsula system
Condition of the Mornington Peninsula system | |||
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Key values | Trend | Condition | Comment |
Platypus | n/a | n/a | There are no recorded platypus populations within this system. Some appear to provide suitable habitat, but there have been no reliable recorded sightings or captures in Melbourne Water’s monitoring program that began in 1995. The absence of platypus may relate to historic fragmentation of habitat. |
Fish | Improving | High | The trend in the fish population since the 1990s has been an improvement in abundance and species richness. |
Frogs | n/a | Very high | The diversity of frog populations is very high, with all species expected being observed. |
Birds | n/a | Low | Steamside and wetland bird ratings are low. |
Vegetation | Improving | Low | Vegetation has been highly modified and condition is low. Fragments of remnant vegetation in moderate condition still occur along waterways. |
Macro-invertebrates | Stable | Moderate | The macroinvertebrate score is moderate and has been stable since the 1990s. |
Amenity | n/a | Low | The amenity score for Mornington Peninsula waterways is low. Most waterways flow through agricultural land although some are protected in National parks. Many of the lower estuarine reaches are highly valued for their amenity value. |
French & Phillip Island system
Condition of the French & Phillip Islands system | |||
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Key values | Trend | Condition | Comment |
Platypus | n/a | n/a | There are no recorded platypus populations. It is unlikely that the waterways would have supported platypus since the islands were separated from the mainland due to the lack of suitable habitat. |
Fish | n/a | Very high | The fish communities are in very high condition. The absence of introduced fish is noteworthy. |
Frogs | n/a | Low | Based on limited available data, the diversity of frogs is rated as low. |
Birds | n/a | Very low | Based on streamside birds, the condition is rated as very low and works aim to improve this over the next 20 years. |
Vegetation | Improving | Low | Vegetation condition is generally low although areas of good remnant vegetation exist within parks and reserves. |
Macro-invertebrates | n/a | Low | The condition of macroinvertebrate communities is highly dependent on water quality. Increased urban development, especially on Phillip Island, will affect macroinvertebrate condition, which is low. |
Amenity | n/a | Moderate | Waterway amenity often plays a secondary role to coastal amenity in this system. However there are a variety of waterways for the community to enjoy. Based on limited data , amenity is rated as moderate. |
The current condition of waterways & wetlands has been used to identify expected outcomes for the future (Targets). Melbourne Water will lead efforts to achieve these outcomes (Leadership) and arrangements are in place to monitor and report on progress and success (Monitoring and reporting).