Big River Watch is a simple way to look more closely at your local river and contribute valuable information about its health. Grab your phone, head to a river near you and spend 15 minutes recording what you see.
The next Big River Watch takes place from 18–24 September 2026 and everyone can take part, you don’t need any previous knowledge or experience.
What is Big River Watch?
Big River Watch is a citizen science survey led by The Rivers Trust that gives everyone the opportunity to help build a clearer picture of river health across the UK and Ireland.
It takes place twice a year, encouraging thousands of people to visit a river and record what they can see.
During your survey, you’ll spend around 15 minutes watching the river and answering simple questions about things such as:
- wildlife and plants
- signs of pollution
- the condition of the river and its surroundings
The information you submit becomes part of a growing dataset that helps river specialists understand where rivers are doing well and where they may be under pressure.
How to take part
You don’t need to be a river expert, an existing volunteer or have specialist equipment.
1. Download the free app
Download or update the Big River Watch app before heading out. It includes useful wildlife and pollution guides to help you identify what you see.
2. Find a river
Choose somewhere you already know and love, or use Big River Watch as an excuse to discover a new stretch of river near you.
3. Watch for 15 minutes
Spend some time really looking at the river. Record wildlife, plants, signs of pollution and your observations about its condition.
4. Submit your survey
Upload your observations through the app and they’ll become part of the wider Big River Watch dataset.
And you don’t have to stop when Big River Watch week finishes – the app remains open throughout the year, so you can continue recording observations from your local river.
Why does your river need you?
Rivers can tell us a lot when we take the time to look.
Wildlife sightings can show where nature is thriving, while litter, discoloured water, excessive algae or other signs of pollution can help highlight where rivers are under pressure.
Bringing thousands of observations together helps build a much bigger picture of river health.
Big River Watch data can help identify where problems are occurring and support decisions about actions such as river restoration, clean-ups, wetland creation and other measures to help rivers recover.
Every survey adds another piece of information – and every person taking part spends a little more time noticing and connecting with their local river.
Big River Watch across the South East
People across our region are already making an important contribution.
During the April 2026 Big River Watch, across the South East Rivers Trust region:
- 332 people took part
- 183 river surveys were completed
- participants contributed a combined 83 hours of river watching
People recorded everything from kingfishers and riverflies to pollution and habitat pressures.
That local information complements the evidence we gather through our own monitoring, restoration projects and work with communities across the South East.
At the South East Rivers Trust, evidence helps us understand where rivers need support and informs the practical action we take with communities, landowners and partners.
From observing your river to helping it thrive
Big River Watch can be a great first step if you want to do more for the rivers around you.
Across the South East, our volunteers and communities help rivers in many different ways – from practical river restoration and litter picks to citizen science and monitoring.
So if spending 15 minutes beside your river leaves you wanting to get more involved, we’d love to have you with us.
Take part in the next Big River Watch
Between 18–24 September 2026, find a river near you, spend 15 minutes observing it and help build a clearer picture of river health. Anyone can take part and no previous river knowledge is needed.
