Only rain down this drain!

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yellow fishes sprayed on storm drain

You and your students may have noticed small, yellow fish painted next to storm drains in your local area. What does this mean and how can your students get involved? Let’s find out…

What is a storm drain?

Storm drains come in all shapes and sizes – typically they consist of a hole in a paved surface which is covered by a metal grill – but they all do the same important job. They connect to drainage pipes that transport excess rainwater to the nearest river. Without them, we would have many more floods than we currently experience.

How do storm drains carry pollution?

Allowing pollution to enter these drains is like pouring it directly into the local river. Common pollutants that make their way into storm drains include paint, oil, cleaning chemicals, rubbish (especially plastics) and milk (which is surprisingly bad for rivers!). Pollution can also be caused by leaks that allow the foul waste from toilets, showers, baths and sinks to enter storm drains. Once in the storm drain, pollution flows through the drainage pipe, directly into the local river (without being cleaned at a sewage treatment plant) and eventually to the sea.

Why does this matter?

Pollution entering a river can seriously affect water quality and the environment. The effects can be acute (short term impact) or chronic (long term impact) and can range from creating an eye-sore to the killing of fish and wildlife. Allowing pollution to enter a river is a criminal offence!

Many of us have been watching Blue Planet 2 and are starting to have a better understanding of the damage that humans are doing to the oceans. The pathway from the storm drain to the sea is a prime example of how plastic pollution is finding its way to the sea – even if we live hundreds of miles away from the coastline.

What can your students do to help?

The Environment Agency has launched a campaign to help tackle this problem, and it is very easy for students to get involved. Students use a stencil and spray paint (under supervision and taking the correct safety precautions, of course) to mark all the storm drains in the school grounds. They then run an awareness campaign to let other students know what the fish symbol means. If you are not allowed to mark the pavements permanently, temporary marks like chalk can be just as effective at getting the message across. Full details including curriculum links can be downloaded from the Environment Agency’s website by clicking here.

This is a simple and purposeful project that will result in real improvements in the quality of water in your local river. Sharing the message of ‘only rain down the drain’ will contribute to stopping pollution from entering our oceans.

If you get involved with the project, we’d love to know how you get on – please feel free to share any updates on Twitter (@AffinityWater) or Facebook (, or email