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Tag Archives | climate change

Floods Ignite Raising Warragamba Dam Wall Debate

In late March 2021 an extreme rain event on the Australian East Coast caused serious flooding which endangered people and property in many areas including the Hawkesbury-Nepean Valley on Sydney’s outskirts. The Hawkesbury-Nepean Valley flood highlighted the dangers of urban development in flood-prone areas given the high likelihood of more climate change-induced flood events in future.

The rain event and resulting floods have intensified debate on the controversial proposed 14 metre raising of Warragamba Dam Wall.  Many experts and conservationists contend that the most extreme floods are unlikely to be stopped by raising Warragamba Dam wall. Flooding in the Hawkesbury-Nepean Valley comes from other river/creek sources in addition to water flowing over Warragamba Dam wall. In addition the geography of the Hawkesbury-Nepean area restricts the amount of water that can flow out of the Valley.

The Colong Foundation for Wilderness states that the raised dam wall proposal is being driven by pressure from developers.  As part of the Warragamba Dam wall raising proposal, Infrastructure NSW plans to house an additional 134,000 people on the Hawkesbury-Nepean floodplain in coming decades. The Foundation states that people in new and existing residential developments in the Valley will not be safe from future extreme floods even if the Warragamba Dam wall were to be raised.

The Foundation states that the proposed dam wall raising will lead to flood water inundation of World Heritage listed Blue Mountains National Parks and wilderness streams and desecration of rare and ancient natural heritage and Indigenous cultural sites.

Adding weight to arguments against the raised dam wall proposal, the Australian Insurance Industry recently withdrew their support for the Proposal due to concerns over the probable loss of important cultural sites and natural habitat. The Industry suggested that the State Government should investigate alternative measures to mitigate flood risk in the Hawkesbury-Nepean Valley.

Alternative flood mitigation actions available to the State Government include improving floodplain evacuation routes such as the Castlereagh Connection, pre-emptive dam-water release water and relocating people in the most flood-prone areas. NSW Deputy Premier John Barilaro recently stated that alternatives to the dam wall raising need to be considered including lower water levels and building desalination plants for water supply.

 

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Adapting to climate change

Our changing climate is bringing new risks which bushwalkers and outdoor adventure enthusiasts should keep in mind whenever planning trips, and whenever we head out on our adventures.

This page gives a quick summary of what to consider. Click through to the relevant authority for detailed information, alerts and to subscribe to alerts and news from each authority.

Extreme weather

The consequences of our changing weather are:

  • More National Park/State Forest/etc closures + more track closures – due to:
    • Threat of fire
    • Damage from fire/flood making tracks unsafe and/or impassable
  • Dehydration & heat stroke of greater concern in hot summer days
  • Increased chance of flooding
  • Poor air quality making prolonged exercise inadvisable (see below)
  • A new Fire Danger Rating

That is why it is important for you to check conditions before you head out. Also monitor conditions for rapid changes. For example, on high fire danger periods/days, or during extreme rainfall, etc.

Avoid remote areas during bushfire conditions. Look at the forward forecast fire ratings and weather before multi-day trips and err on the side of caution.

National Parks closed and damaged by fire

Air quality & health

Air pollutants, including smoke from bush fires, can be harmful to our health and so check air quality forecasts before you head out.

NSW Department of Planning, Industry and Environment states that we should all reduce heavy or prolonged exercise when the Air Quality Index (AQI) is >150.

However, The Climate and Health Alliance have now declared: “There is no safe level of air pollution. The higher the level of pollution, the more hazardous the risks to health. Bushfire smoke is particularly hazardous because of the high levels of tiny particles (PM2.5).”

You can check the current and forecast air quality here: https://www.environment.nsw.gov.au/aqms/aqi.htm

And find out what the AQI colours mean for your activity here:

https://www.health.nsw.gov.au/environment/air/Pages/aqi.aspx

Leaders should cancel activities to areas likely to be affected by poor air quality.

Fire Ratings

Note that a new Bush Fire Danger Rating exists called “Catastrophic”. If a Catastrophic warning is issued when and where you are planing to be in the bush, you should cancel your planned activities and move to a place of safety.

A “Catastrophic” rating may be issued in advance so always check the forecast if you are planning/heading out to a multi-day activity.

The current RFS advice for what you should do if the Bush Fire Danger Rating is “Catastrophic” is:

  • For your survival, leaving [the area to be affected] early is the only option.
  • Leave bush fire prone areas the night before or early in the day – do not just wait and see what happens.
  • Make a decision about when you will leave, where you will go, how you will get there and when you will return.
  • Homes are not designed to withstand fires in catastrophic conditions so you should leave early.

See the RFS for full details of Bush Fire Danger Ratings including “Catastrophic”: http://www.rfs.nsw.gov.au/fire-information/fdr-and-tobans?a=1421

Learn more about Bush Fire Danger Ratings and Total Fire Bans here: https://www.rfs.nsw.gov.au/fire-information/fdr-and-tobans

Fire damage

Every time you head out – check:

To manage these hazards always check before you head out:

Hot Spots

These new tools may indicate fire activity, however the site creators say they are “not to be used for safety of life decisions. For local updates and alerts, please refer to your state emergency or fire service.”

Always remember, that this information is only as updated when a satellite passes over the location you are viewing. IE: not that often.

https://firewatch-pro.landgate.wa.gov.au/ (seems to be more current just from our casual observation)

https://hotspots.dea.ga.gov.au/

Alerts

  • Bushwalking NSW does not pass on alerts. Instead, we recommend you sign up for alerts directly with the relevant authority
  • Bushwalking NSW periodically remind our newsletter subscribers that people and clubs should check for alerts:
    • In anticipation for activities
    • Before they head out
  • Sign up to our newsletter at the bottom of this page and here

Subscribe to updates

  • We encourage all people engaged in outdoor adventure to sign up to receive alerts from the relevant authorities.

Clubs

  • We suggest clubs consider how they are communicating with their members when conditions become hazardous or extreme.

 

We hope this brief guide helps you all to continue to enjoy safe and successful outdoor adventure in our beautiful natural places!

CSIRO Conducts an Ecological Change Project and You Can Help

A national online survey is being conducted by the CSIRO and the Department of the Environment and Energy.

The survey will help them to understand how Australia’s bushland and biodiversity has been changing in recent years, and whether the 1°C increase in surface temperature experienced over the past century may have contributed to these changes.

If you have a strong, long-term relationship with the land and are passionate about the future of Australia’s special plants and animals then the CSIRO would love to hear from you. The survey will collect first hand observations, insights and stories about places that are changing and places that aren’t changing. For example, you may have observed new species appearing, plants flowering at unusual times, or trees dying in your area. This will provide a unique and important historical record for Australia and the CSIRO would love for you to participate.

To participate, you would need to be able to select a natural area (e.g. your local region or farm, a Nature Reserve, urban bushland) that you have been familiar with for at least the last 10 years. Note that they are interested both in areas where change has been observed and where change has not been observed.

The survey would take about 30 minutes. If this has sparked your interest, additional information about the full project can be found here.