MBCL SUBMISSION TO CITY OF KINGSTON

LOCAL PLANNING SCHEME AMENDMENT L33

DATE: 11 August 1998

THE GREEN WEDGE

The Framework Plan, a joint review for Greater City of Dandenong and City of Kingston, concluded that "there is strong strategic planning, environmental and landscape grounds to reconfirm the long term value of the non-urban area (the green wedge) from a metropolitan and local perspective".

The land subject to the L-33 Amendment is in the green wedge in the City of Kingston. Whilst much of the site is severely constrained by flooding, opportunities exist for the creation or restoration of wetlands and open space.

Mordialloc floodplain"The Panel does not accept the notion that . . .the area is unsightly, degraded, blighted or unattractive and thus ripe for urban development. The Panel accepts.. .that the adoption and siting in the wedge of beneficial uses which are incompatible with residential amenity but suited to large lot sizes and open landscapes was a practical way of providing for the management of this part of the green wedge"(1).

The Strategic Review recommends that any development in the green wedge must genuinely address the landscape, amenity, ecological and hydrological objectives and limitations.

"Conventional residential development in this section of the study area will not further these objectives and is not recommended" (2).

Within the green wedge concept a range of rural and urban related uses are considered appropriate:

Uses that are not considered appropriate are urban uses such as residential, rural residential, industrial, commercial (3).

700 houses built on a flood plain with a high water table is a gross over-development of the site and conflicts with the green wedge concept.

Kingston Lodge Site

An absolute maximum of 200-250 houses could possibly be considered as a "low density environmentally based residential development" but only after "assessment against the detailed environmentally sustainable design criteria".

City of Kingston's Strategic and Policy Justification of the Amendment L33 claims:

"Amendment L33 provides a structure plan for the subject land consistent with the general thrust of the recommendation of the South East Non-Urban Study (SENUS)".

However SENUS states:

" 5.3. The Principal Finding of the study is that the concept of the green wedge is supported and must be maintained. This is consistent with the context of the State government's policy as outlined in Living Suburbs" and

"Major urban conversion is not supported. Any such consideration must only be made in context of a metropolitan wide review of growth areas" (4).

700 houses on the subject land must be considered as a "major urban conversion" which will set an unfortunate precedent by encouraging developers to further erode the green wedge.

OPEN SPACE

The proposed 700 house residential development and wetland proposal does not allow for public recreational space therefore extreme pressure will be placed on Braeside Park.. The Keysborough Non-Urban Review states:

"Visitor rates for Braeside Park have steadily risen since it opened in 1989. They will continue to rise, especially since the Government is encouraging increased housing densities and urban consolidation within the metropolitan area. Smaller backyards may mean that a greater demand will be placed on public reserves. Braeside Park will need careful management to ensure that the public recreation function is not realised at the expense of the Park’s conservation objectives. Conservation can also be threatened by the urbanisation of surrounding land. The southern portion of Braeside incorporates wetlands which provide an important bird habitat and breeding area. The success of the latter depends largely on the site's isolation from intrusive human activity such as noise bright lights. This would be jeopardised if urban uses are allowed to encroach onto adjoining land"(5).

The lack of public recreation space could be partially overcome by restricting the number of houses (200-250) to the north east corner of the subject land and reserving all land south of the ‘lake’ for wetlands and a nature reserve.

THE WETLANDS

The land subject to the L-33 Amendment is flood prone land at the northern most sector of the Carrum-Carrum Swamp flood plain. Flood plain drainage work last century connected Mordialloc Creek to Dandenong Creek via the Mordialloc Main Drain. This brought about significant changes to the creek estuary. Provision of sufficient exchange and storage of tidal water is now needed to flush the estuary. Any extension of the estuary will have to look carefully at the net tidal exchange and projected residence time of waters in the estuary, particularly at the time of salt water intrusion (6).

"Potential uses for the Mordialloc Main Drain segment lie with widening the drain and establishment of verge wetlands in the flood prone lands north of the levee banks. This area could be developed into a linear park with wetland habitat similar to that which previously existed in the area and which would complement or extend Braeside Park" (7).

However, the area is still liable to flooding. Areas subject to inundation are the undeveloped properties bounded by Mordialloc Settlement Drain, Governor Road, Springvale Road and Mordialloc Main Drain. Studies of flood management schemes have been carried out and the conclusion reached is that:

"Extensive filling of the Mordialloc Main Drain flood plain is unacceptable due to significant increases in peak flows.(around 20% to 50%)" (8).

Whilst some filling of industrial zoned land at the western end of Canterbury Road may be acceptable,

"The remainder of the Mordialloc Main Drain flood plain should remain unfilled in this area. The flood plain of Mordialloc Main Drain to the west of Springvale Road is also of major significance as a store for flood waters and should be preserved in its present condition without filling in order to ensure that downstream flood problems are not exacerbated" (9).

SALINE INTRUSION

Since the proposed wetland on the subject land is described as a series of freshwater wetlands, it is necessary to consider possible saline intrusion into the system. This can arise due to a number of factors. For example, Dr AB. Pittock claims that as a result of predicted climate change:

"Changes in the water balance will also lead to changes in the water table. Where rising water tables are indicated this could lead to increasing problems of soil salinity, particularly in inland river basins" and

"a concern for future management of wetlands is the possibility of increased flood frequency due to the greenhouse effect"(10).

BUFFER ZONES

Any wetland in close proximity to residential development must have an adequate buffer zone.

"Buffers are essential, particularly in urban areas, to provide a safety margin in which animals can detect and hopefully, avoid predators, as well as providing a screen between disturbing human activities and natural bird behavior. A buffer zone can be a valuable filtering area to protect the wetland as a whole from pollutants and weeds. The provision of buffers to wetlands is Government policy" (State Conservation Strategy 1987).

A buffer zone of 20 to 25 metres is considered completely inadequate. The Wetland Investigation Committee recommended a 300 metre buffer from the normal winter flood level around wetlands.

CONCLUSION

Given that there is the inevitability of increased flooding in the Mordialloc Creek Estuary and upstream due to climate change and storm surges; and that a buffer zone of 300 metres is necessary to give adequate protection to the wetlands, the southern section of the proposed wetland development below the ‘lake’ must remain undeveloped to act as a meadow wetland/ flood plain to alleviate flooding problems downstream. A 200-250 house low density environmentally-based residential development could be located in the northern sector of the subject land.

AUTHOR: M. Rimington

 

END-NOTES

(1) Gutteridge, Haskins & Davey P/L (1998) Greater City of Dandenong and City of Kingston: Strategic Review of the Keysborough Wetlands Area: A Framework Plan, Feb.

(2) Ibid., p. 1.

(3) Spiller Gibbins Swan (1997) South-East Non-Urban Study Final Report, Feb, p. 46.

(4) Ibid.

(5) Dept. of Planning & Housing (1992) Keysborough Non Urban Area Review: Background Report, Aug., p. 76.

(6) Anthony Moodie & Associates P/L (1989) Mordialloc Creek Catchment Flood Management Study: Final Report (for DVA), Oct., p. 41.

(7) Ibid.

(8) Ibid., p. 91.

(9) Ibid.

(10) Pittock, B. (1987) "The greenhouse effect" in, Engineers Australia, Feb 6.

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