River filters are the hazards boaters, kayakers, and other paddlers encounter while on the water. Strainers are obstructions on rivers that let water flow past them, but solid objects like people and kayaks cannot.
A strainer on a river is a hazard that allows water through but prevents the movement of people and vessels. A common example of a river strainer would be a large pile of rocks that boats cannot cross. Other strainers include dams and dense plant growth that prevent passage.
A river filter may be any number of obstacles in a river that allows water to pass through, but it would capture and retain objects, including people. A river strainer strains a river of large debris, boats, or even people or animals, only allowing water to pass through the tiny gaps inside the obstruction. A strainer is an obstruction within a river’s body preventing water from flowing.
The Utility of River Strainers
A river strainer occurs when an obstruction exists in water where only a few gallons of water are allowed to flow through at one time. Such obstacles may become clogged and obstructed in the narrowest part of a river, creating a perfect river strainer. While it is true that a snag is a ubiquitous river filter, there are more objects and obstacles which can cause a filter in the river.
While it is true that a filter in the river bed, such as a tree falling, is most likely to be seen, this is not always the case. The filter’s most dangerous part is not the obstruction itself but rather the current flowing through the strainer. Anything that could create a barrier to a river, but allows water to pass through, can make for a potentially deadly trap known as the strainer.
This potentially deadly trap allows water to flow through an opening or gulf in obstruction, but it strains the river from boats or kayaks, animals, large debris, and rowers. Strainers trap debris, crafts, and other objects, forcing water to flow through the minor gaps in an obstruction.
If caught in one, the tremendous pressure of the water could pull you under. Filters can get even more dangerous when the wrong type of kayak is used in a river. Filters on rivers can become hazardous when kayaking, canoeing, or fishing. To help you keep an eye out for these river hazards, we put together this quick guide to keep you safer on the water.
The Issues with Snags and Skimmers in Rivers
Snags and skimmers are among the more dangerous obstacles you are likely to encounter when paddling. One of the most challenging obstacles in a swift-moving river is the sweeper (sometimes called the filter).
Filters are among the most dangerous features found on rivers. They can be hazardous on rivers or streams as they can get trapped by a snag. The snags may not be visible to an unwitting casualty and may be encountered by river runners, kayakers, or rescuers when they are not expecting the rafters.
Filters are distinct in appearance depending on orientation through the water. Strainers are trees that fall in the water, with the branches acting as filters for water flowing through them. Filters are usually trees or other trash partially submerged in the stream.
The most dangerous filters are found at an outflowing creek curve, where water volume and flow are higher. The bends in the creek or river are the most dangerous places to find filters, as the flow and importance of the water could drag your kayak across to the side of the filter.
A river strainer can be fatal for an individual’s kayak should it get caught, and it should be avoided at any opportunity. As a result, many people have little to no chance of being caught in a filter since they generally seek out more tranquil river bodies. You have the highest probability of being caught in a filter amid flood seasons.
River flows allow hazardous at this time, filled with blockages. Even when the river is never inundated, flowing water is still disruptive to the land over which it passes. Excessive flow causes riverbed erosion, resulting in trees falling into rivers.
Additional Notes on River Snags and Drains
A river snag may be caused by various objects, including natural and artificial obstructions, such as branches, flooded vehicles, and fences. A filter could be anything from a downed tree trunk to a large rock in the middle of a riverbed. A filter could be a crack in a rock or a grouping of boulders through which the water passes. A filter allows the water to flow out of a hole in an obstacle, but the gap is not large enough to let larger objects pass through.
River drains are created from naturally formed or artificial obstacles that allow water to flow through, but they trap larger objects, holding them in place. Because of how filters work – by allowing water to flow through but catching larger objects – the real danger is being caught up against an obstacle held in place by the sheer force of the water. Artificial strainers, like deck pilings, fish traps, nets, and trash, are extremely dangerous and could trap a boat or a swimmer.
Strainers are a potentially deadly obstruction and should be avoided if at all possible. Strainers can occur from various things and may happen naturally or as the result of artificial obstacles, particularly in floods and heavy rains. A snag is one of the more dangerous situations kayakers may face. To avoid this strainer/sweeper, steer your kayak towards the obstacle and then back-stroke or back-channel your kayak into the current.
Other water-level strainers can appear as the horizon lines,or as an ine-like spill-over, says Swift Water Rescue. Before heading out for a kayaking trip, make sure you have checked National Weather Service water level data on gauges near a creek or river that you are planning on paddling.
