The Dangers Of Low Head Dams And Other River Obstacles

The Dangers Of Low Head Dams And Other River Obstacles

If you are looking to ensure that your boating journey goes safely, it helps to be informed about the possible hazards that you may come across. We are going to discuss some of these obstacles and why they may end up posing a danger to your life. We will also advise you on how to manage these obstacles best.

The most dangerous variety of obstacle that you will come across is the low head dam since these dams are a type of river strainer that can end up injuring you or worse. Before we take a closer look at low head dams, we will go over what a river strainer is and why it is so dangerous.

What Are River Strainers?

You may be wondering what exactly constitutes a river strainer; boating is dangerous enough without unnecessary obstacles, and river strainers are one of those barriers you may have to deal with. When there is a strainer in river, there is an obstacle through which water can pass, but solid objects cannot.

River strainer.

You may be wondering exactly why this may be dangerous. If you are trapped against a river strainer, you will find that it can be difficult or even impossible to free yourself. This is because you will be pinned against it by an unfathomable amount of water pressure, especially in stronger rivers.

Being pinned against a river strainer will ensure that you are incapable of escaping, as you will be unable to swim away and very rarely even able to climb the obstacle against which you are pinned. It will be especially hard to escape if you are pinned up against a smooth surface, like a low head dam.

What Is A Low Head Dam And Why Is It Dangerous?

A low head dam is a type of dam that does not go past the surface of the water; this is the meaning of the term “low head.” These dams are meant to increase water height on a particular side by only letting a certain amount of water spill over the top and into the other side, which creates two bodies of water of varying heights.

A low head dam is not only dangerous because the upstream (higher) side of the dam acts as a water strainer, trapping a swimmer against the structure. This is reason enough to make a boater worry.

The other reason why low head dams are dangerous (and some would call this the main reason) is that they create a vortex of water on the other side just beneath the water surface. This current acts as an undertow and pulls you under the water.

Low head dam.

This current is even capable of stopping boats dead if it is powerful enough. Since low head dams are situated beneath the water, you will find that they are sometimes impossible to notice until it is too late. This is why you should always be on your guard.


We hope that we have been able to accurately present the dangers posed by river strainers and low head dams. Please use the information that you have learned in this guide to keep safe while boating.

Resources: Boat-edUSAToday