Canyoning in the rain

Intro

I think that taking risks is a good thing.

Let me qualify that statement:  I think that taking calculated, carefully considered risks with consideration of aims, objectives, skills, abilities and experience - and having an adequate back up plan - is a good thing.

Canyoning in the rain, after rain, or when rain is forecast is risky. And canyoning in the rain is one area where much planning, preparation and consideration is required. The reality is that recreational and commercial canyoning trips regularly go ahead after rain, during rain, and when rain is forecast. Canyoning in the rain can be very dangerous, cold, and scary. However, more often than I would have thought, I have found canyoning in the rain to be beautiful, fun, and tremendously rewarding

Big organisations like NASA, the Military and many others use various complex systems for making decisions about complex situations. Things like Risk Informed Decision Making (RIDM) or Multiple Criteria Decision Analysis (MCDA) all sound pretty impressive until you realise that they’re just a fancy way of saying “it depends”.

Information Sources

Canyoning in the rain is a very complex thing to make decisions about and as canyoners there are a number of tools available to us in Australia that can help us with our decision making.

• The Bureau of Meteorology (BOM) website has a range of useful tools available. It’s really worth spending time diving in and exploring around as there are many useful features that most users aren’t aware of. Aside from the standard forecasts issued, here are some particular sections that are worth taking the time to understand:

  • MetEye - MetEye allows you to look at forecast rainfall over a specific area down to 3x3km square (or 6x6km in more regional areas) and for a particular 3 hour window. An incredibly detailed feature when you dive in.

  • Radar – a great way to look at how intense a storm is right now. This tool is used a lot for shorter canyons like Empress because you can see if storms are approaching before you leave the carpark. It gives you a great perspective on storm direction, speed and intensity. The radar can also provide a rough idea of rainfalls in the last 24 hours (although there are significant limitations with this feature the further north and east you go, eg. in to the Wollemi Wilderness).

  • Forecasts and Observations. The BOM site doesn’t just give forecasts, it also provides access to their observations (records of what actually happened). Have a look at the last few days or even weeks. Has the Wollangambe catchment seen a lot of rain in the last week? Then maybe that extra 10 - 20mm forecast overnight is something to be concerned about for your trip tomorrow.

• Other weather apps and interpretation services – There are so many that I won’t make comment on any specific services here but these are worth considering.

• Increasing mobile phone coverage in many of the more popular canyons close to towns means that the ability to make decisions on the day, in the carpark, or even at the entry to the canyon is increasing.

• Blipmap or Windy – detailed information about wind speeds. Useful to figure out how cold you might get, but also for giving you clues as to how fast the weather might change (a cold front or storm approaching for example) during the day.

• RFS, NPWS and BMCC track status and closures – keep an eye on their websites for updates about recent burns, scheduled burns, and other updates (including track closures and more).

• River height data is available from the BOM and http://new.mhl.nsw.gov.au/ Data about the Grose River, Glenbrook Gorge, Wolgan River and other river heights can be useful to determine how saturated a broad area might be.

Aside from these digital services, there’s some old fashioned data sources you can make use of too:

• Got a friend in the area? Make use of their local knowledge. “Hey Dave, long time no see. Well enough chit chat. How’s the weather?” Of course make sure you buy them a beer/coffee/milkshake at your next opportunity. My previous workplace had the benefit of being part of a very active canyoning and climbing community that lives in and nearby the most popular canyoning areas. Combined with the fact that we are all out in the bush quite regularly, and spend far too much time debriefing at the pub, it makes for quite a decent collective knowledge about canyon conditions, catchments, flooding and more.

• But one of the most useful tools is to go for a bushwalk. A lot of my friends are simply really curious about flooding – so when our work got cancelled due to flooding we tended to go out there and see what it is like anyway (sans customers!). Sometimes this means walking down to the canyon entry, having a look at a raging torrent and walking away. But other times it means going to a known alternative exit, sometimes it means abseiling in to have a look and exiting via the same rope. And still other times it involves finding out that we could have gone after all, and so we add that to our mental bank and keep learning there too.

I must stress though, while our mental bank builds up and we find out more about when we could have gone, we also know the value of walking away! Swallowing your pride, saying you got it wrong and making the brave decision to disappoint some people is the best thing to do. The first 4 times I went out to Twister and Rocky Creek I never made it past the first waterfall in Rocky Creek because the more experienced leaders that I was with deemed the water levels too high to safely reverse the obstacles.

Flooding Variables

Canyon flooding is a complex subject with a number of variables including (but certainly not limited to):

• high water markers

• rainfall total volume, (usually measured in millimetres)

• rainfall intensity, (volume of rainfall in a short time frame)

• rainfall location (highly localised storms can effect very small areas),

• dryness of catchment/soil saturation levels, (is the ground able to soak up any more moisture or is it saturated?)

• size of catchment, (how much area there is to catch the rain)

• type of catchment (an urban catchment is usually more “responsive” to rainfall events – like turning a tap on and off),

• steepness of terrain, (flat land floods less than steep land because the water moves more slowly and has more time to soak in or wash away)

• soil profile, (shallow soil on bedrock will have more runoff)

• soil type, (sandy soils will absorb more water than clay)

• vegetation type, (some vegetation types will hold more water and act like a sponge)

• recent bush fires, (typically burnt catchments flood more easily due primarily to changes in the soil and vegetation leading to much more run off and much faster responses to rainfall events, it often means there is more debris too)

• canyon profile, width and depth, (a narrow, deep canyon can fill to a depth of many metres with only a small amount of rain)

• obstacles present within the canyon, (“pinches” in canyons can block flow meaning still waters upstream and raging torrents downstream)

• natural dams (soil, logs, vegetation, rocks and more can back fill and burst releasing torrents of water)

• man made features (dams can buffer flooding to a point – once the dam starts spilling any further rain can cause extreme flood events)

• and much more.

Each canyon has quite unique behaviour after rainfall and there are no hard and fast rules for any waterway. Experienced canyoners instead rely on their extensive knowledge of the catchment, normal flow rates and the effect of increased flow on obstacles in the canyon, recent climatological data, recent impacts on the landscape (eg bushfires), and much more. They then pull this information together to make decisions relating to their canyoning plans.

And the best way to get this experience? Go and have a look! Next time your planned canyon adventure gets rained out, instead of staying at home rugged up next to the warm glow of your computer screen, go and spend the day walking to the entry and exit points of canyons that you are familiar with. Spend some time matching up what you saw in the canyon with weather forecasts and observation data available to you. Take photos, note high water marks, and start building your knowledge to be able to make better decisions in future.

And the worst case? You’ll do a splendid bushwalk in the rain seeing waterfalls at their fullest and trails at their quietest, and if you’re really lucky the walk in will feel like a canyon in its own right!

Participant considerations

It is very important when planning to go canyoning in the rain to take calculated, carefully considered risks with consideration of aims/objectives, skills/abilities and experience of those in the group. And always have an adequate back up plan.

Excellent canyon leaders will take in to consideration the aims and objectives of the group. For example, trainee canyon guides on a rescue training course might perceive some rainfall as an excellent opportunity. They may enter a canyon with higher than normal water levels because the increased water levels are not only in line with their aims and objectives but also (under supervision from an experienced leader) are also in line with their skills and abilities. On the other hand, leaders on a recreational expedition involving school children on their first canyon experience should perceive increased water levels very differently. They should have a much lower tolerance for the associated risks and make extra conservative decisions accordingly.

Some things to consider about your group may be whether participants have previous experience in abseiling, canyoning, bushwalking, rock climbing, swimming, rafting or other white water activities? Or you made need to make an assessment of their physical ability, strength and agility. Your assessment may also include a range of other interesting things like any pertinent medical conditions, language barriers, cultural considerations, mental capacity or behavioural considerations.

It is worth reiterating that being clear about your aims and objectives for the day is very important, but being acutely aware of the aims and objectives and the abilities of the rest of your group is absolutely critical.

Aims and Objectives

Excellent canyon leaders will take in to consideration the aims and objectives of the group. For example, trainee canyon guides on a rescue training course might perceive some rainfall as an excellent opportunity. They may enter a canyon with higher than normal water levels because the increased water levels are not only in line with their aims and objectives but also (under supervision from an experienced leader) are also in line with their skills and abilities. On the other hand, leaders on a recreational expedition involving school children on their first canyon experience should perceive increased water levels very differently. They should have a much lower tolerance for the associated risks and make extra conservative decisions accordingly.

Some things to consider about your group may be whether participants have previous experience in abseiling, canyoning, bushwalking, rock climbing, swimming, rafting or other white water activities? Or you made need to make an assessment of their physical ability, strength and agility. Your assessment may also include a range of other interesting things like any pertinent medical conditions, language barriers, cultural considerations, mental capacity or behavioural considerations.

Here’s an example of a very specific decision that was made at my workplace about a school group that we were responsible for taking through Fortress Canyon (generally considered an introductory canyon) in 2014: 

• One of the group leaders for the proposed trip had been through Fortress Canyon a number of times during the significant rain events we experienced in the summer of 2012/13

• His benchmark from those trips were that we had experienced 150mm of rain (50mm per day for 3 days). He then went in to the canyon on the 4th day and whilst the water levels were up, he had a fun and safe trip through the canyon. 

• He also said that the water levels dropped visibly while he was in the canyon (watching the water volume at the end of the canyon while eating lunch) which indicated that the area is a fairly quick draining catchment.

• The predicted rainfall for the day before the trip that we were considering was 20-40mm and whilst it had been raining on and off for the previous week there had been no significant rainfall volume in that period (less than 10mm per day).

• The rainfall predicted for the day was 5-10mm.

• This same experienced canyoner who was in the canyon during the high water levels last season was going to be one of the leaders on the trip the next day, which meant that when he arrived at the start of the canyon he would be able to compare the water levels to known high water benchmarks from previous trips.

• We chose some clear indicators for us to use as “red flags” for us to reconsider our decision. For example: If there was over 50mm of rain on the day before the trip (20-40mm was predicted for the region generally) then we would look more closely at the data.

• We considered the student’s abilities - all were studying an outdoor recreation subject at their school. All were relatively fit and known to us, and had previous abseiling and bushwalking experience. In addition to this, all of them could swim confidently.

• We considered the school objectives and concerns of the principal and parents – whilst an adult group might want to push the boundaries a little, when working with students the decisions needed to be like those of a ‘prudent parent’. 

• We also came up with a back up plan: our group was travelling a long way and we didn’t want there to be the pressure of disappointment. We planned to use Deep Pass Canyon (lower predicted rainfall for that area) or a multi-pitch abseiling trip as an alternative adventure if there was any doubt in our minds.

On the day, we experienced less than the predicted rainfall on the preceding day and the forecast on the Bureau of Meteorology site was more favourable on the morning of the trip. We went ahead with the activity, ended up experiencing lovely weather, healthy (but not abnormal) water flows and the students had a great time.

It is worth reiterating that being clear about your aims and objectives for the day is very important, but being acutely aware of the aims and objectives and the abilities of the rest of your group is absolutely critical.

Moving water in the Blue Mountains

Blue Mountains Canyons are not moving water canyons. They are low flow. White water skills are another skill set altogether that I do not have and don’t wish to make comment on. White water conditions require different skills, systems and equipment. Additionally, introducing high water flow in to an area that does not normally have high water flow produces additional risks that aren’t present in white water canyons in other parts of the world (dams bursting, more debris floating, etc) and as such I would strongly caution against even experienced white water canyoners from entering a Blue Mountains canyon in flood.

Canyon familiarity

The last thing that I think is worth considering if you are planning on going canyoning in the rain is about how well you know the route through a particular canyon. Things that are worth reflecting on include (but are certainly not limited to): 

• location of alternative exits (and equipment required)

• where there is high ground you can escape to within the canyon (including places where you can camp in the canyon)

• the usual "choke points" on the waterway where water will back up/dam

• places where white water hazards are known or likely to form (eg the last pool in Empress is a doozy)

• alternative anchors that are available (in case the ones you were going to use are under water!)

• what additional equipment you might need (eg equipment for building anchors in case the ones you were planning to use have been washed away)

• what techniques you might use (or avoid) given certain water flows

And most importantly, do you know alternative canyons(!) that would be a better choice today? Perhaps today is the day to try virtual canyoning...