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No. 14 Dam a stream

Visitors walking by the stream at Bodnant Garden, North Wales
Visitors walking by the stream at Bodnant Garden, North Wales | © National Trust Images/Paul Harris

Adventure no. 14 on our list of ‘50 things to do before you’re 11¾’ is dam a stream. What could be better on a warm day than getting into the stream and trying to block it? Just collect twigs, branches, stones and rocks to stop the flow of water.

Choose your material

Generally, stones, rocks, sticks and leaves are the best natural materials to use to build your dam. Experiment and see which materials are the strongest and most useful. Sand and gravel may also be helpful, depending on the strength of the current and the size of your stream.

Choose your spot

Which part of the stream looks like the best place to dam it? You may want to start off at the narrowest point and see how successful you are. Then you can tackle larger and deeper sections of the stream as you master this skill.

Look at the shape of the stream. Is it bendy or straight? If it has bends, then you might want to think carefully about where to dam the stream. Does your dam make the water slow down or change direction? Can you influence the direction in which it flows and perhaps channel some of the water to another section of the stream instead?

You can also make a dam on the beach if there is water running into the sea. Can you plug one of the little streams that run from the river out to the sea? There’s plenty of seaweed and sand about for you to use.

Use your senses

What can you see happening now that your dam is built? Is there anything floating in the stream that has become stuck against it? What’s in it? Can you see fish or other creatures around?

How does the water sound when it flows or rushes to meet your dam? Does it trickle through? Has it stopped completely to gently lap against the walls? Is it swirling or splashing?

What goes up must come down

After you’ve taken time to appreciate your creation, it’s important to restore the flow of water again. Wildlife further downstream may depend upon the water and what it brings. So have lots of fun smashing the dam down afterwards.

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