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What is a Trash Screen?

Patrick Roland
Patrick Roland

A trash screen is a type of fencing used to filter out debris in the path of a waterway. This is a helpful tool in keeping streams, rivers and lakes free of trash and unwanted elements. The basic design of all trash screens is similar, but internal, external and turbine-powered screens each serve different needs. Screens also can be made of different materials.

A basic waterway trash screen is made from any type of meshed material that allows water to pass through but holds back large pieces of debris. A trash screen usually is made from the same materials as many fences, such as metal or plastic. Depending on the waterway and the amount of pollution that passes through, screens often need to be cleaned regularly in order to avoid waterway blockage.

Man with a drill
Man with a drill

A trash screen normally is constructed from non-corrosive metal wire. Usually, it is a section of fencing made from aluminum. The size of the openings can be controlled by the type of fencing used, such as a backyard fence with larger holes or chicken wire fencing with smaller openings. In addition to metal fencing, plastic fencing, like the kind used for snow fences, also can be used. This method is less expensive than metal but runs the risk of deteriorating quicker because of the constant exposure to water and pressure.

The most common type of trash screen is the external screen. These screens are placed in the middle of a stream, usually at its narrowest point. The fence is anchored by metal posts that go deep into the ground. The screen spans the width of the waterway and normally goes under the waterline as well. Ideally, any piece of debris floating down this path will be captured by the screen in order to avoid further contamination.

Internal screens are popular for drainage systems. When it rains, most cities have water runoff on the street, and this water eventually is filtered into a nearby waterway. Many communities place trash screens within the drainage system to capture any debris that came through from the street level in order to keep it from reaching the waterway.

A more complex type of trash screen is the water-powered, turbine-driven trash screen. This self-sufficient piece of machinery has a water wheel that is turned by the stream's flow. This wheel powers a turbine that uses a screen to sweep the water and automatically remove trash.

Discussion Comments

popcorn

We have a pretty deep ditch in the back of our property that regularly has a bit of water flowing through it. For some reason or another the city came and installed a trash screen at the end of our ditch and it has become a bit of a problem for us.

What we used to jokingly refer to as our moat, is actually getting clogged up by the trash screen the city installed. We had quite the flood the other week because part of a tree got stuck in the trash screen after a big storm.

We're not sure if we're responsible for cleaning the trash screen or not, but we really think the city should be in trouble for causing a miniature flood on our property. Things were just fine before that trash screen got installed.

wander

I live in South Korea and there are actually multiple trash screens that are used to keep debris from getting into the larger bodies of water here. Starting with the sink in your kitchen, it has a little netted basket that is designed to catch anything too large. From there the building has another trash screen and finally if you walk down to any of the city channels you can see more trash screens in place.

Whenever I walk to work I usually see one of the city maintenance men out there cleaning out all of the branches and trash. You would be surprised what sorts of things get stuck in them. I once saw a tire being yanked free from a screen.

kylee07drg

Trash screens really do need to be cleaned out often. Our town installed one, but then they neglected to check on it after a downpour. They may as well not have gotten one.

It had the same effect as a beaver dam. Large branches, leaves, and pine needles accumulated behind the screen. There were so many of them that they blocked the flow of water through it.

As the rainwater in front of the screen washed on downstream, the level of the stream past the screen dropped a good bit. The level behind the screen stayed high because of the artificial beaver dam it had caused.

During the next big rain, the water level rose dramatically, and the debris rose with it. All the trash that was being held back by the screen flowed over it, defeating the purpose of having one.

Oceana

It was probably a stupid thing to do, but my friends and I used to swim in a big stream nearby. Most of the time, it was only about shoulder-deep at its deepest point.

We didn’t know about the trash screens in the stream. They had been placed there a couple of years after we started swimming in it, and since we never watched the news, we hadn’t heard.

We were all swimming along side by side. Suddenly, a couple of us screamed out. Something was down there, and we had grazed it. Two of us cut our feet on the sharp wire edges.

We hobbled home and doctored our wounds. We decided not to swim there anymore.

cloudel

A trash screen saved my wedding ring. I had to wade through a culvert to retrieve it, but I got it back.

My fiancee had just proposed the night before. I was standing in the street, telling my best friend about the proposal. I had the ring still in the box in my purse, because he had told me to take my time and think about it before putting it on.

I took out the ring box, and at that moment, a strong gust of wind blew it out of my hand and into the runoff ditch. The current was swift, and my friend and I chased the box as it headed toward the giant culvert.

The water was only a few inches deep, and the culvert was big enough for me to stand up in, so I went in after it. A fine mesh trash screen had been placed in the middle of the culvert, and there, I found my ring box.

lighth0se33

A large stream runs through my town, and it has trash screens at various intervals. After a big rain, this stream can resemble a river, and it can easily carry items as big as tree trunks on its current.

A couple of years ago, a young girl in our neighborhood went missing. Her parents were the prime suspects because of situations surrounding her disappearance, and the investigators feared that she might be dead.

They searched the woods, which led to the stream. We had just had a major rainstorm, and the current was strong. They found her body caught in the trash screen.

If that trash screen hadn’t been in place, her body could have floated far away. She may never have been found.

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