Public Works Committee: Lake Hawdon North Regulator On-Ground Works Project

Mr BROWN (Florey) (11:38): I move:

That the 85^th report of the committee, titled Healthy Coorong, Healthy Basin Program—Lake Hawdon North Regulator On-Ground Works Project, be noted.

The submission from the Department for Environment and Water, hereon referred to as 'the department', will make improvements to the wetlands at Lake Hawdon North to increase the habitat for key species of migratory and resident Australian non-migratory shorebirds. This project is part of the Healthy Coorong, Healthy Basin Program and aims to benefit Coorong water birds by increasing their preferred foraging habitat and supporting natural dispersal and rain shifts to mitigate and adapt to climate change.

The Coorong is a wetland of international importance, recognised by the Ramsar Convention on Wetlands, as well as by a number of international migratory bird agreements. Its complex mix of diverse freshwater and hypersaline wetlands is perfect for supporting a diverse and abundant waterbird community. The wetlands have seen a prolonged period of ecological decline, causing a noticeably diminished number of waterbirds, migratory shorebirds and fairy terns. Feasibility studies by the department are optimistic that the proposed regulator can help maintain the ecological health of the wetland and extend habitat availability while long-term management solutions for the Coorong are investigated. The improvements at Lake Hawdon North aim to improve issues of ecological decline by:

increasing the water management capability of the wetland through the construction of the wetland regulator, a fish ladder channel and a secondary regulator and bund;

increasing duration of watering at the site to maximise opportunities for shorebird foraging; and

improving access to the site by upgrading necessary segments where service vehicle access is impeded. This will also aid and facilitate monitoring, improving maintenance and increasing site visitation.

These improvements will increase the department's capabilities to prepare and react to different environmental scenarios as well as increase the greater management area. The at-risk bird species prefer waters less than 10 centimetres deep, and these improvements will allow management of water heights and volumes to accommodate these needs. The improvements will also create and manage refuge areas to improve foraging conditions, increasing the wetland's potential to support over 25,000 waterbirds.

The project will build a regulator, a small dam-like structure, that will control the flow of man-made Drain L, which bisects the western edge of Lake Hawdon North. The construction will include a fishway that will bypass the structure and allow fish to circumvent the regulator. These works will include:

earthworks within Drain L to create the necessary base width and invert level to accommodate the regulator;

trimming of batters for more stable earth elevation changes;

rock armouring of the drain base and batters, both upstream and downstream of the regulator;

earthworks to either side of the construction area to allow access to the top of the regulator;

the construction of a five-metre wide crushed rock track to facilitate construction, operation and maintenance of the regulator;

a solar power supply and control system for the automated operation of the flow gates;

a raised access track along the edge of the fishway to enable operations, maintenance and the movement of nearby stock;

new fencing and gates around a stock access track as well as along the drainage reserve boundary; and

relocation of an existing permanent survey marker.

The estimated construction cost of the project is $8.8 million and is funded on a 90 per cent Australian government and 10 per cent state government breakdown. To minimise risks presented by weather delays and high water levels, construction is planned over the summer months, commencing in November this year, and is expected to take place over a six-month period. There is the option for additional works the following summer, if necessary. If these additional works are required, completion is expected by March 2026.

The department will seek approval from the Department for Infrastructure and Transport to self-manage construction under its oversight. Tonkin Engineering has been appointed as the lead professional services contractor and will be responsible for managing site investigation works, progressing the concept and finalising detailed designs. The delivery of the project will be through a construct-only contract to be appointed by tender, and Tonkin will continue in an advisory role to review designs, give technical advice and provide input during the construction phase.

All procurement will be managed in accordance with the state government's procurement management framework, governed under the existing Healthy Coorong, Healthy Basin governance framework, and will comply with associated guidelines. Contract management will be undertaken in accordance with the department's contract management procedures.

The project is expected to benefit the local economy and the community in the South-East. Local business will be boosted in the short to medium term through capital investment during construction, operations, maintenance and labour contracts as well as through the purchase of equipment, materials and construction.

Increased tourism may also benefit the community through an increased demand for goods and services. The project also has the potential to support local First Nations communities via direct and flow-on benefits. A considered focus on environmental, economic and social outcomes associated with wetland improvements could sustain these economic and community benefits for decades to come.

The department has compiled a sustainable development report outlining the project's sustainability principles and objectives. Throughout the planning and design process, several environmental assessments were undertaken to identify and understand potential project issues and impacts, especially in relation to vegetation, fauna, Aboriginal heritage, site contamination, groundwater, water quality, erosion and sedimentation. The Climate Change Unit of the department has been consulted to ensure delivery of the project is in accordance with relevant policies and guidelines.

Lake Hawdon North is subject to the First Nations of the South-East No. 1 title claim area, and the department has engaged with First Nations of the South-East representatives during key steps of the project. This has included through concept development, detailed design development and cultural heritage surveys. The department notes more cultural heritage surveys may be required before construction.

Native title holders have identified that the area has significant cultural and ecological value and have expressed support for interventions which have minimal ground disturbance activities and will improve the health of First Nations of the South-East country. No Australian government or state heritage places are located within or adjacent to Lake Hawdon North.

The committee examined written and oral evidence in relation to the Healthy Coorong, Healthy Basin Program Lake Hawdon North regulator on-ground works. Witnesses who appeared before the committee were Lisa Stribley, Acting Director, Water Infrastructure and Operations, Department for Environment and Water, and Sarah Murphy, Manager, Program Delivery, Department for Environment and Water. I thank the witnesses for their time. I would also like to thank the member for MacKillop, who presented rather fulsomely to the committee regarding this project in his electorate.

Based upon the evidence considered and pursuant to section 12C of the Parliamentary Committees Act 1991, the Public Works Committee reports to parliament that it recommends the proposed public work.

Mr McBRIDE (MacKillop) (11:46): It gives me great pleasure just to make a comment on this project reported on by the Public Works Committee and to thank the Chair and the committee, obviously, for considering and supporting these works. As I indicated in my submission, in regard to this development—and I think it is about a $13 million or $14 million proposal—it has some really good environmental outcomes around birdlife, preserving a wetland and keeping it wetter for longer through the drying months of spring; it probably will not reach summer, but it may.

I did raise with the committee that this sort of infrastructure is going in a lake that is part of a main drainage system of the Limestone Coast and particularly, in an area surrounding and east of Robe, that is a very flat, wet land type and country. It does not take much interference in this waterway that not only is a natural lake system but also is part of South Eastern Water Conservation and Drainage Board developments, drains and the like that help take the water out of the countryside so that pursuits of agriculture can take place.

We have already seen the department around 10 years ago put in a temporary weir between Lake Hawdon South and Lake Hawdon North just to hold some water up in Lake Hawdon South in the latter part of winter/early spring. Given the nature of that year, unlike this one, being much drier, it had a major effect on landowners around Lake Hawdon South and flooded them out, and they lost pastures and crops. No-one knew why, because this temporary weir did not have a lot of community consultation or public notification around it.

It was not until they saw the temporary weir that had been put in place—I think they were cement bags put across a channel between Lake Hawdon south and north. It was only about 300 millimetres high or something like that—it was not that high—but the effect was quite astronomical in a wet year because we are talking about falls that are not much in the landscape. I really did highlight this in my submission to the Public Works Committee—that the rain, the water flow, land levels and its flatness do not take a lot of interference.

I am hoping the fact that I am hearing about solar developments and I think solar on this weir tells me it is going to be probably, hopefully, operated from afar. It means hopefully they can monitor this weir in a way where they do not have to always be there and can potentially monitor any sort of flooding that might take place if we have, as we no doubt will, wet springs. As has been alluded to, it is about keeping more water in Lake Hawdon during the spring for fauna and particularly birdlife.

The other thing to note here is that where this weir is going is in a drain that leaves Lake Hawdon North and goes towards Robe and what they call the Robe Outlet. That Robe Outlet is fairly clear and tidal. One of the freshwater lakes on the southern side of Robe is one of the most pristine freshwater lakes in the South-East. It is well and truly supplied well by the drain that comes out of Lake Hawdon through this first freshwater lake and it is known as a bream lake and it has a name that is not with me at the moment.

Between that freshwater lake and back towards Lake Hawdon, the drain is full of reeds, tea tree and silt. What gets lost here is that the drainage board with its small budget and constraints has not been able to clean the drain and maintain the drainage system all that well over the last 10, 20, 30 or 40 years. It is in dire need of extra funding and it has not been forthcoming yet.

My concern is that when the department rolls out this restrictor/weir it might have the effect of holding back too much water which could inundate land and agricultural pursuits, because when they need to let the water go and do so in wet springs, the water does not move fast enough back out through to Robe because the drain is silted up with trees, reeds and other debris. In my understanding, it has not been cleaned for about 30 or 40 years.

I say this because I like the intent of this development and what it is trying to stand for: birdlife in a lake system. Believe it or not, this lake is a lot like another lake called Lake Robe. Lake Robe is basically a salt pan. It has some birdlife on it during the winter when there is water there, but during summer it dries up and it is basically a white landscape because of the salt on the surface.

Lake Hawdon is not like that anymore and the reason it is not like that is because the number of drains that flow into Lake Hawdon feeding Lake Hawdon have flushed the salts out and now we are seeing vegetation, trees, reeds, cover for birdlife and the like. It is almost as if it has been freshened up by man-made interference of, firstly, water allowed to flow in from a number of drains—and I could say four or five—and, secondly, there is an exit out of Lake Hawdon North into Robe and then into the sea. This has actually had a dramatic effect on Lake Hawdon in that it does not even look like what it looked like 100 years ago.

Sometimes man can interfere with these native wetlands and the like and everyone thinks of damage and disaster and it is worse, but this is not the case. This is actually better; it looks better; it is harbouring more life; it is harbouring more cover; and it is more vegetative. Obviously, now there are bird species coming into Lake Hawdon that can be helped in their journey in life and breeding and Lake Hawdon can play a part and maybe this restrictor and development will also play a part in that.

Really all I am doing, as I did with my submission, is to highlight that we are putting a restrictor/regulator in this drainage system and we need to be cautious, careful and make sure that it works for all the right reasons. I thank the committee and the member for Florey, as the Chair, and all that he does on that committee, and for allowing me to make my submission.

Mr BROWN (Florey) (11:53): I would like to take this opportunity again to thank the member for MacKillop not only for his contribution to the debate today but also, as I said earlier, for his most fulsome presentation to the Public Works Committee. We saw photographs of the member for MacKillop's family using the area, we saw maps that the member for MacKillop had prepared and I must say that the committee was a lot better informed about the operation of drains in the South-East after the member for MacKillop's presentation than we were before. I thank the member for MacKillop for his presentation to the committee and also for his contribution today.

Motion carried.