On a world scale, Blue Mountains canyons are relatively safe. They are typically dryish, with only small numbers of canyons requiring long swims. Most waterfalls have little flow most of the time. The canyons are comparatively warm. Unlike many canyons around the world, their water does not come from snowmelt. They are less prone to flash flooding, as most have small catchments, and the catchments are fairly well vegetated, which slows the run off of water. Dangerous canyon formations such as siphons and keeper pot holes are rare or non-existent. Anchors are usually readily available, and don't change much from year to year.
Nevertheless, numerous incidents happen each year, and people do die.
Below are some safety issues to be aware of when canyoning.
- For canyons requiring swimming, every member of the party should be able to swim. This may seem obvious, but can be extremely dangerous if not checked beforehand. Remember by doing the waist belt up and floating on your back, a daypack with a dry bag in it makes excellent flotation.
- For canyons requiring abseiling, every member of the party should have their own abseiling equipment. I have heard of parties occasionally passing harnesses and descenders back up abseils. This is usually very slow, and in a cold canyon can endanger both your parties and others behind you. In addition, people should be familiar with the harness and descender that they are using, another reason to have their own.
- Hypothermia is a real risk. For canyons involving swimming, you should consider having wetsuits and/or lilos for each party member. I carry a set of thermals and a beanie on every canyoning trip - even if you don't need them they can be useful if someone in your group gets into trouble. See Keeping Warm for more details on how to keep warm in canyons.
- What if someone becomes hypothermic? The important thing is to get the victim warm. This can be difficult in the canyon, as there is usually little sun and a high likelihood of things being wet. In some instances it may be necessary to push on to an exit. In other cases you may be able to stop and light a fire.
- Flash flooding. Flash floods have been the cause of at least 5 deaths in canyons near Sydney. While a 'wall of water' is unlikely, the water can rise very rapidly, sometimes several metres in a matter of minutes, and can generate a powerful current. If you are trapped in a narrow, high-walled section there may be little or no opportunity to scramble up high to safety. Be very cautious about canyoning when thunderstorms are forecast. In the canyons with very large catchments (eg Wollangambe), it may be possible for a thunderstorm to have dumped rain in the upper catchment without you even being aware of it. See Catchment Sizes for some information on the catchment size of various canyons.
- Jumps. Water jumps can be fun. They can also be dangerous. The opportunity for a slip or misjudgement is always there, particularly when the jump has a challenging take off or landing zone. Jumps should generally be checked out by the first person for depth and hidden obstacles. Even if you have done it before, logs are regularly washed from pool to pool and may be hidden below the surface. Very few jumps are compulsory - it is rare that a belay point cannot be found. Even where there is no belay point, it is often possible to use other techniques to get the first person down.
- Canyons are slippery places. Wear lightweight, covered shoes with good grip. Dunlop Volleys are popular and have good traction on wet sandstone. Watch out for dark green or black looking rocks just above or below the surface of the water. The colour often signifies that they are covered with algae and these ones are extra slippery.
- Helmets should be worn where there is a risk of falling rocks. The canyons around Kanangra and Bungonia in particular are susceptible to falling rocks. The abiding memory of the first time I visited Bungonia was the continual 'tinkle' of small rocks tumbling down the cliffs, just from the heat of the day. Helmets are also handy for protecting your head from getting cold and giving you a breathing pocket when abseiling under waterfalls.