WCCM Canyoneering Rating and Difficulty System
As canyoneering continues to grow in popularity the need for a difficulty rating system has emerged just as it did for rock climbers years ago. ATS has developed a methodology for canyoneering called the West Coast Canyoneering Method or WCCM. The WCCM is a make up of existing traditional approaches and evolved techniques and systems combined. The need to expand on the existing rating system is based on the wider range and types of canyon routes being established now compared to the desert type “slot canyons” that stereotyped the image of the sport in the early days. Desert canyons are quickly becoming just a small part of the established canyon routes nationally and worldwide. ATS has been a component for the pioneering and establishing of routes across the west coast including the Sierra Nevada range, Arizona, Southern California desert and mountain regions, and Hawaii. The WCCM rating system was conceived in the early 2000′s as an evolution of the popular Yosemite Decimal System that rock climbers currently use to grade routes in the United States. Although there are several rating systems in use in the United States for climbers (YDS, Alaskan), the Yosemite Decimal System continues to be the preferred choice. As such, ATS felt it would be a natural and uncomplicated step to have a comparable rating system for canyoneers to use.
As with all types of rating systems, this one is designed to assist a group and its leaders in assessing and matching the skill levels of each canyon descent member against the obstacles in the canyon. Never rely solely on a canyon difficulty rating or a route description as routes change and the perception of the individual’s establishing and rating the route may be different than your own. In addition, there are multiple ratings systems in use for canyoneering around the globe that all share similarities, but posses key differences. Do your homework on which rating system you are using, talk with folks who have recently done the route using message boards, call or e-mail an instructor or guide to verify conditions and ratings. Information is virtually non-exhaustive. A good canyon leader will do everything in his or her power to become and stay informed to past, current and expected conditions. Due diligence is only a small part of this puzzle. Professional training, proper equipment, group size management, mindsets, time of year, etc… are all contributing factors for success or failure. Be safe and then have fun!
Canyon Classifications:
Class 1: A canyon that can be traveled in either direction (i.e. up or down) and most times of the year, usually along a streambed on an established trail. No commitment, no real exposure to water, no technical gear required.
Class 2: Again a non-committing canyon which can be traveled in either direction, mostly “off trail hiking” with some route finding skills needed to possibly stay dry or skirt larger obstacles. No technical equipment needed.
Class 3: Again a canyon route that can be traveled in either direction. Substantial route finding and climbing / boulder hopping skills needed to ascend or descend. Deep wades, small swims may be possible along with exposed down climbs followed by additional sections of class 2. A group harness and small rope may be a smart item to bring in the event of an injury.
Class 4: A committing and technical canyon route to be descended with various specialized rope systems, down climbing, swimming, deep wades along with teamwork skills. Typically once the rope is recovered form the first rappel the group is committed to a “descent only” egress. A serious approach to Time Energy and Risk management is necessary. Special attention to layering systems as often exposure to cold water is unavoidable.
Class 5: An extremely committing canyon route with all the tributes of a class 4 canyon route combined with the additional skillsets needed for lead and aid climbing. Technical pothole escapes, tricky lead climbs for egress, or any other difficult obstacle that would require the use of climbing and belaying skills. A class 5 canyon is an expert canyon usually attempted by a smaller group of competent canyoneer’s.
The Water Ratings:
Water or flow rates vary from canyon to canyon, time to time, storm to storm and year to year! Calling a canyon class “C” because there is water flowing through it is too vague for our standards! Detailing a canyon by any amount of water flow should be done on more of a case by case. Our water flow rating system is a conditional measurement. Not a set rating!
Class A: Virtually dry conditions. (“Seasonal” pools of water may exist)
Class B: Minor to moderate water flow rates with deep wades and or swims.
Class C*: Heavy flow rates. Class “C” conditions have difficult and dangerous hydraulic scenarios. Strong swimming skills and rope setting skills needed to safely negotiate the watercourse.
*Note: For a route to qualify as a class “C” canyon it must posses at the time of descent hazardous currents that a leader must swim against to set up swift water or class “C” rope systems. The amount of CFS running in a canyon is not an indicator of a class “C” as every canyon has the capacity to drain water at different levels. If you are swimming, the route is not necessarily a class “C” conditional rating by default.
Class F: A canyon that has been exposed to fire. Mud slides, rock fall, burned out root systems of trees and bushes, debris dams make for a dangerous condition. See many routes in Southern California as regular examples.
A class “A” canyon can become class “C” during a heavy rain, a class “C” canyon can become class “A” during a drought. Water flow ratings are so variable that they should only serve as part of your initial size up of the route. If you don’t have swiftwater skills, stay away from faster moving water filled canyon routes until you have received proper training. It only takes a small amount of water set with the perfect canyon topographical conditions to create a water hazard by definition. Use good judgment!
Time Commitment Ratings:
Grade I: Short roadside classics. 1-2 hours
Grade II: 2-4 hours
Grade III: Solid half day 5-7 hours
Grade IV: Long day 8-12 hours. Usually depending on group size, conditions and speed
Grade V: Two-day canyon, Bring more Red Bull!
Grade VI: A hypothetical rating for more than two days. Usually at this point the canyon crew will be aware of the canyon length and will have made all the necessary related decisions to manage the canyon T.E.R.M’s.
Danger Ratings:
Danger ratings are again hypothetical. It can be argued that any canyon could have sections of “R” or “X” ratings. True, but here we are talking about “unavoidable scenarios” the difference between a mandatory jump and not mandatory may be the lack of suitable anchor, etc… Body belays may protect the majority of the group but not the last one down. These ratings are simply designed to encourage the canyoneer to look deeper into the demands of the route. A danger rating describes unmanageable risks such as known hydraulic features, necessary jumps or dangerous slides.
R: A mistake at the wrong place or time will result in an unavoidable injury.
X: A mistake at the wrong place or time will result in an unavoidable death.
Example Ratings:
Class 3-B-III
Non committing, Wet, half day scramble
Class 4-C-V-R
Committing, Heavy water flow & current, Two day canyon with possible unavoidable hazards such as mandatory jumps, slides or swims
Class 5-C-VI-X
A committed advanced canyon route with heavy water flow & current, lead climbing required for egress or pothole escapes, multi-day with the possibility of unavoidable deadly obstacles or hazards
[...] Class: 4 C IV+ [...]