Adapting Marks Point and Belmont South

Thank you for your question Graeme. While we did work with our Community Working Group on the newsletter and on this graph, you are correct when you point out that the graph does not show the measured data and projected trends accurately. It is designed to illustrate clearly the concept of “triggers for action” being linked to actual lake levels, whatever the
projections. To do this the lines have been drawn as clearly separated. In fact the lines of measured-rise and modelled-rise have coincided closely over the last 20 years – at about 3mm a year - and are projected to remain fairly close for the next 20 years or so. After that, the level is projected to accelerate,
particularly in the second half of the Century, if carbon emissions continue a high levels – showing a much steeper gradient, as you say.

The graph in the Newsletter shows the projected increase in lake levels since 1990, and the legend on the y-axis should read “Increase in lake level (metres)”, which is measured from a
“0” point in 1990, as shown. Our apologies for this error.

The average water level in the lake in 1990 was about 0.1 metres AHD, so the projected water levels in the lake are 0.5 metres AHD by about 2050, and 1.0 metre AHD by about 2100. The lines shown on the graph are a projection between these three points in time.

Thanks for your question. Our online discussion board is moderated and at this point in time has two generic topics - 'what are some ideas/options for managing the flood risk?' and 'what would a successful plan look like? Other ways to start a conversation is through this 'Ask us a question' function as these topics and questions are published on the website. Please reply with the topic you'd like to discuss or receive more information on. We appreciate your involvement. Many thanks, Kate

Thank you for your question. Council assesses all requests to clear out drains on a case by case basis so you can call 4921 0333 with details about a specific drain and a service request can be lodged. Generall.y mangroves grow between the high and low tide line, where drainage is
controlled by the level of the lake not the fall of the land. However, they can colonise further along drainage lines which can impede flows. Clearing mangroves for any reason requires a permit from the State Government Fisheries Department to preserve and protect threatened tidal wetland ecosystems. A Review of Environmental Factors (REF) may also be required by Council. Council is working with NSW Fisheries to make this process easier to help improve drainage services throughout the City.

Thank you for your well-researched inquiry. Lake Macquarie Council monitors information from tide gauges in Lake Macquarie (Swansea, Belmont and Marmong Point) to help us understand what is happening with levels inside the lake. However, the analysis of this information is done by experts at the National Tidal Centre in
Canberra and the Manly Hydraulics Laboratory in Sydney, as this is a specialist area and requires the knowledge and experience of scientist who work in this field of study. As the Lake Macquarie gauges are not fully calibrated against land levels, for example, they only measure relative changes in lake levels. The Belmont gauge (the most consistent record) shows a relative rise of 2.6mm per annum from 1986 to 2012. The reasons for his rise may be due to factors such sea level rise, channel dredging, land sinking, or a combination of such factors.

Council does not do independent analysis of the Newcastle or Fort Denison gauges, but the information from these gauges (and many others) is used widely in the many studies and analyses that go into the scientific advice on trends and projections in ocean levels provided to Government and Councils by expert bodies such as the CSIRO, Bureau of Meteorology, National Tidal Centre, and the NSW Chief Scientist. Lake Macquarie Council is not “opposed” to using these records – in fact, they are incorporated in most of the advice we receive. The latest summary of sea level trends around the Australian coast based on tidal gauge and satellite measurements can be found in the Bureau of Meteorology’s 2014 biennial State of the Climate report .

Council does not do independent
analysis of the Newcastle or Fort Denison gauges, but the information from
these gauges (and many others) is used widely in the many studies and analyses
that go into the scientific advice on trends and projections in ocean levels
provided to Government and Councils by expert bodies such as the CSIRO,
Bureau of Meteorology, National Tidal Centre, and the NSW Chief Scientist. Lake
Macquarie Council is not “opposed” to using these records – in fact, they are
incorporated in one way or another in most of the advice we receive. The latest
summary of sea level trends around the Australian coast based on tidal gauge
and satellite measurements can be found in the Bureau of Meteorology’s
2014 biennial State
of the Climate report

Thank you for drawing our attention to the update required in our information sheet on home insurance and flooding. We can confirm that several insurance companies are now providing cover for oceanic storm surge. There are very few properties in Lake Macquarie that are affected by this hazard.

Council does not deny that projected sea level rise will have impacts on some properties – the purpose of local adaptation planning is to identify these impacts and decide how best to manage them, so properties are protected and remain safe from future flooding. As confirmed recently by the Insurance Council of Australia, sea level rise projections have no impact on flood insurance premiums, which are based on the insurers’ assessment of current flood risk for the period of coverage – next year, not 2050 or 2100.

Flood maps showing the 1:100 year flood envelope (shaded yellow) for Lake Macquarie are available in the Lake Macquarie Waterway Flood Study (Figures B2-B9), although it is difficult to identify individual properties on these maps. More detailed maps are available for the Marks Point and Belmont South adaptation planning area. Council is up-grading its GIS mapping system, and expects detailed flood mapping, showing flood extents on individual lots, should be available on our
web page in the near future. If anyone is unsure if their property is affected by flooding they should contact the Customer Service Centre on 4921 0333 or [email protected]

Thanks for your question Pat. The simple answer to your question is “yes, wherever possible”. Council is working with local communities to develop long term plans to manage the increased threat from future flooding and rising lake levels. This includes the best way to maintain residents’ access to and use of their land. Some simple measures such as protective foreshore berms, progressive filling, and raising the level of local roads can prevent land and roads from being inundated. However, coordinating these
actions and ensuring local drainage is maintained requires good forward planning. Although properties and roads are not likely to be severely affected for several decades, local adaptation plans will give owners certainty about actions to protect their land, and Council can start setting-up new foreshore protection works, and revising design standards for new road and drainage works, for example.

Hi there, Thanks for your enquiry about Myall Road Soccer Field. Our Planning for Future Flood Risks project is currently looking at the areas of Marks Point and Belmont South. Similar to our social media pages, our Have Your Say site is not used for logging and responding to service requests. I’ve forwarded your comment back to Council's Customer Service team for action. If your property is particularly badly affected by rain events, please contact Council on 4921 0333 and provide details of your problem so we can investigate and respond. Many thanks, Kate

Thanks for your interesting observation. Council would be very interested to receive any information you have collected showing changes in the swan population between seasons or over the years. The Hunter Bird Observers carry out monthly surveys of wader and waterbirds along Swansea Channel, including Swan Bay, and the results can be found on their website: http://www.hboc.org.au/index.cfm?menukey=6 Earlier this year, Council retained the "Natural Waterway" zoning for Lake Macquarie to protect its natural values, while still allowing responsible use of the lake for recreation. The Lake Macquarie Mooring Management Plan is due for review by the NSW Roads and Maritime Service, and there will be the opportunity for public comment and submissions before it is finalised. You can contact their Newcastle office on 13 77 88 for more information.

Thanks for your question. Council has responded to 14 service requests for drainage or flooding issues in Marks Point so far in 2013. 70 per cent of these service requests have been resolved or closed. If there is a specific issue such as a blockage or a poorly located inlet it can be raised through a service request by contacting Council's Customer Service Centre or 4921 0333 or [email protected]. If you're able to provide a brief description of the problem and an address or detailed location that would be great. Photos can help too. In general, it is difficult to ensure good drainage in very flat, low-lying areas such as Marks Point or Swansea, as there is very little fall between the inlets and the outlet into the lake. This means the water flows slowly and the pipes are more prone to blockages from sediment and litter. In this current stage of the community engagement we are looking at different options to manage future flood risks in Marks Point and Belmont South. Many thanks, Kate