Public Works Committee: Port Road Drainage Project

Mr PEDERICK (Hammond) (11:36): I rise to speak to the first report of the Public Works Committee in the 54th parliament regarding stage 2 of the Port Road Drainage Project and commend the committee, with members from both sides of the house making sure we get the right outcome as far as drainage works on Port Road are concerned. This is a continuation of the works identified in the City of Charles Sturt Port Road Rejuvenation—Stormwater Management Plan.

The stage 2 works comprise the installation of approximately 2.6 kilometres of underground twin-cell trunk drain between Old Port Road, Cheltenham, and Park Street, South Woodville, as well as service relocation. I note that it has been mentioned there is a major powerline relocation that has to be been done as part of these works, as these services need to be relocated to accommodate the trunk drain alignment. Obviously, there is the associated streetscaping along with this.

The stage 2 works are an integral part of the Port Road Rejuvenation—Stormwater Management Plan. As part of that stormwater management plan, the key aims of the work are flood management, providing existing properties' floor levels with flood protection at or above the 100-year average recurrence interval, and ensuring that new development does not degrade the level of flood protection to existing properties.

Stormwater quality is obviously something that needs to be looked at, improving the quality of stormwater discharges to West Lakes in particular, and, in recognition of the high recreational value of West Lakes, providing a reduction in pollutants, nutrients and sediments entering West Lakes. In the past, we have had blue-green algae outbreaks in West Lakes, and there are probably not many in this place who can remember when the area was essentially swampland. It is now quite a picturesque suburb. However, according to the report, this stormwater management will only improve the quality of the water in West Lakes.

There is also the opportunity for stormwater re-use, so it is about encouraging opportunities for the on-site retention of stormwater and the beneficial use of stormwater, and that is always a good thing. When we have a year like this where it has been quite dry coming into winter—certainly at home at the farm at Coomandook we have not had a lot of rain. We have had almost enough, but it is probably never enough in a year like this that has been a very tight year, in an agricultural sense, in a range of areas.

That reflects right through to the city, to our catchments and to the ability to have enough water to utilise not just for critical human needs in regard to drinking water but, obviously, water that we need for other things. As I said, we need it out in the country for our farmers, but in the city the water that is needed for parks and gardens and other uses, quite rightly, could be re-used stormwater, just to save the drain on the Murray.

I was heavily involved in discussions during the time of drought. We were not getting those flows down the River Murray through 2006, 2007, 2008 and 2009, and some big decisions were made around the size of the Desalination Plant. It was built at 100 gigalitres per annum, which obviously was twice the size of what we proposed at around 50 gigalitres per annum. It is costing us all a fortune to keep it running, because the plant has to run at somewhere around 8 per cent or 10 per cent capacity to keep the membranes wet so that if we do need—and let's hope this does not happen—to wind that plant up to 50 per cent capacity or even full capacity, which I doubt but who knows, we need to know that the membranes and the whole state of that plant will function appropriately.

The appropriate use and re-use of stormwater is vital. The extended drought was a turning point in our state's history, which was not relieved until September 2010 when the Darling water first flowed down the river for the initial recovery and then we had the water from the Southern Basin come through the Murrumbidgee and the other rivers that feed in to the Murray and, once again, it came back to being the 'mighty Murray'. However, let's not forget that if it does not rain then we do not fill the dams that are needed for Adelaide's water supply, the next option is pumping out of the Murray, and the next option after that is the Desalination Plant.

I understand it is always a balancing act for the operators of the water system, SA Water, about how much is pumped and how much will we get to fill those dams. I sincerely hope that we get a good winter but, because of the way this season has come along, it does concern me greatly. We need to make sure that any works like these that go into place maximise the capacity of the stormwater that we can re-use. It is absolutely vital that that happens.

As part of this report, there is the appropriate environment protection and enhancement, which is maximising the opportunities for urban biodiversity and amenity. The capital cost is close to $20 million, at $19.7 million. As has been stated, 50 per cent of this money is coming out of the City of Charles Sturt council, and that is a huge commitment. There are flooding issues along this road, so the work does need to be done.

Along with this work is the associated site clearing, demolition, disposal, bulk earthworks, backfilling and reinstatement of some land and associated service relocation, as I discussed earlier, to accommodate that large trunk drain alignment. Also needed is the supply and installation of all associated pits and internal connections, tree protection and removal where required, completion of new paved car parking bays and landscaping, comprising trees, shrubs, irrigated grassed areas and associated streetscaping.

I commend the members of the Public Works Committee for their work in regard to this proposal. It looks like the completion of the project may be in August instead of the previously forecast completion in December, so that is something to be celebrated. Any works that can be done in a timely manner, even pre time instead of on time, are a bonus for everyone involved. I hope these works continue speedily and we get the best outcome for managing stormwater along these roads, including the appropriate vital re-use of stormwater, as I indicated before in my contribution. I commend the works.