10.0 Theme 6: Whitewater Classification Inventory
A whitewater classification inventory is an inventory of whitewater classes on a river. It provides the recreation inventory specialist with valuable information on potential recreation activities on the river. These activities, especially paddling, are included and recognized in the river features inventory (refer to sections 4.2.12 and 9.0).
Classifying whitewater for potential paddling activities requires several considerations:
"The difficulty of rapids will determine the types of watercraft which can be used and the approximate experience levels required of river users. It is also important to identify obstructions along a river (e.g. waterfalls, log jams, weirs) which present a hazard to user safety and reduce recreation potential... another important factor in ascertaining river navigability is the change in difficulty which occurs with variations in waterflow levels. Many rapids become easier to navigate at high water, while others become extremely difficult and dangerous... at low water level, similarly, a wide range of possible conditions may occur. The variations are dependant upon the feature or features which create the rapids (abrupt changes in the channel bed gradient, obstructions in the channel bed walls, changes in channel width, bends in the river channel). All rapids, therefore, should be classified at high, medium and low water levels" (Hooper, 1977).
It would be ideal to classify whitewater for high, moderate and low water levels, but it is not feasible to accommodate ever changing conditions of the rivers. River conditions, especially whitewater, can change dramatically from year to year and season to season (e.g. log jams, earth slumps, unusually high seasonal rainfall).
For this reason, the river is classified at the optimum water level for recreation use. The actual water flows for this period can be derived from the Historic Stream flow Summary for the river enabling a comparison for other time of the year. Notes on known changes in classification at different water levels can be included in the description/statement of rationale for each river zone.
This inventory:
Again, the whitewater classifications identified in this inventory are for planning purposes only. It is not meant to be a recreation 'user's guide' for navigation on any river.
The whitewater classification used in this inventory is based on the International Whitewater Classification System (American Whitewater Affiliation, 1990). This system is based primarily on kayaking.
Kayaking
Class I: Easy . Fast moving water with riffles and small waves. Few obstructions, all obvious and easily missed with little training. Risk to swimmers is slight; self-rescue is easy.
Class II: Novice. Straightforward rapids with wide, clear channels which are evident without scouting. Occasional maneuvering may be required, but rocks and medium sized waves are easily missed by trained paddlers. Swimmers are seldom injured and group assistance, while helpful, is seldom needed.
Class III: Intermediate. Rapids with moderate, irregular waves which may be difficult to avoid and which can swamp an open canoe. Complex maneuvers in fast current and good boat control in tight passages or around ledges are often required; large waves and strainers may be present but are easily avoided. Strong eddies and powerful current effects can be found, particularly on large-volume rivers. Scouting is advisable for inexperienced parties. Injuries while swimming are rare; self-rescue is usually easy but group assistance may be required to avoid long swims.
Class IV: Advanced. Intense, powerful but predictable rapids requiring precise boat handling in turbulent water. Depending on the character of the river, which may feature large, unavoidable waves and holes or constricted passages demanding fast maneuvers under pressure. A fast, reliable eddy turn may be needed to initiate maneuvers, scout rapids, or rest. Rapids may require "must' moves above dangerous hazards. Scouting is necessary the first time down. Risk of injury to swimmers is moderate to high, and water conditions may make seIf-rescue difficult. Group assistance for rescue is often essential but requires practice and skill. A strong Eskimo roll is highly recommended.
Class V: Expert. Extremely long, obstructed, or very violent rapids which expose a paddler to the above average endangerment. Drops may-contain, large, unavoidable waves and holes or steep congested chutes with complex, demanding routes. Rapids may continue for long distances between pools, demanding a high level of fitness. What eddies exist may be small, turbulent, or difficult to reach. At the high end of the scale, several of these factors may be combined. Scouting is mandatory but often difficult. Swims are dangerous, and rescue is difficult even for experts. A very reliable Eskimo roll, proper equipment, extensive experience, and practiced rescue skills are essential for survival.
Class VI Extreme. One grade more difficult than Class V. These runs often exemplify the extremes of difficulty, unpredictability and danger. The consequences of errors are very severe and rescue may be impossible. For teams of experts only, at favorable water levels, after close personal inspection and taking all precautions. This class does not represent drops thought to be unrunnable, but may include rapids which are only occasionally run.
Three additional classifications are included in the above list to reflect all water conditions along the river. They are not part of the International Whitewater Classification, but are included to reflect all conditions on the river or inventory status. These classifications are: flatwater, unrunnable and unclassified.
Class 'F': Flatwater. Stationary or slow-moving water with no riffles or waves. Few obstructions, all obvious and easily missed with little training. Risk to swimmers is slight; self-rescue is easy.
Class 'U': Unclassified. No inventory information available.
Class 'N': Unrunnable. Beyond class VI - this class represents drops thought to be unrunnable (e.g. dams or very high waterfalls).
The whitewater skill level for canoeing and rafting is not the same as the 'kayaking' skill levels. This difference should be taken into account when determining the potential for (non-kayaking) activities.
According to Pratt-Johnson, the suggested skill level criteria for open canoeing and rafting includes:
Open canoeing
Novice: Has successfully paddled calm lakes, but is inexperienced on moving water.
Intermediate: Experienced on Class I moving water and can handle class II.
Expert: Can maneuver on Class III water, and can sometimes successfully run Class 4.
Rafting
Novice: Can handle Class II water.
Intermediate: Can maneuver under full control in Class III .
Expert: Can maneuver under control in Class IV water, and can possibly handle Class V.
She also states that whitewater classifications are merely an indication of actual river conditions. Some river conditions may increase the whitewater classification suddenly. These include: regional differences in conditions; long travel time to nearest road; cold water; glacial water; and logs. Logs can appear on any river in B.C. and are one of the most dangerous hazards on waterways (especially on very narrow rivers and creeks). Consequently, these 'extra' hazards would increase the whitewater classification in some cases (e.g. a Class II with cold water and/or logs would be bumped up to a Class III).