Join The Big River Watch from 18th to 24th September 2026 
 
Spend 15 minutes by a river and help us build a clearer picture of river health across Sussex and beyond. 

Our rivers have really felt the heat this summer. High temperatures and low water levels have placed additional pressure on wildlife and can leave rivers more vulnerable to pollution.

To protect and restore our rivers, we first need to understand what is happening to them - and that is where you can help. 

From 18-24 September, we are inviting people across Sussex to take part in The Big River Watch: a free citizen-science survey that turns simple observations into valuable evidence about the health of our rivers. 

Whether you visit the Ouse, the Adur, the Uck, or one of the many smaller streams and brooks that flow through our landscape, your observations can help reveal how our waterways are changing.  

 What is The Big River Watch?  

 The Big River Watch is a week-long citizen science survey, held twice a year, that helps to build an important picture of river health across the UK and Ireland. 
 
  
  
By taking part in The Big River Watch from 18th to 24th September, you can help us understand how our rivers are coping. Together, these individual observations create a much bigger picture of river health. The results can help organisations such us here at the Ouse & Adur Rivers Trust, identify problems, understand where rivers need support and make a stronger case for action. 
  
The process is fully accessible and requires no specialist skills to take part. It is easy and can engage young people and families too. All you need is a smart-phone app, to visit your local river for only 15 minutes – and record your observations and findings. 
   

How to Take Part

Step 1: Download the app
   
Download or update the free Big River Watch mobile app before visiting the river.
   

Step 2: Complete the survey by your river
   
Spend 15 minutes watching the river and answer the simple questions in the survey. 

  
You can do this at your favourite spot on the riverbank. The survey will ask you about what you see, from wildlife and plants to any signs of pollution.
   

Step 3: Upload your survey
   
Press submit, and upload your Big River Watch survey! 

Find out more + Download the app here    
  
*If you don’t have a smart phone, you can still download the survey.  

 River specialists will analyse the results and upload them to the national River Watch Data Dashboard, where you can watch the results flow in.  
 
The data you collect will also be sent to us here at OART and added to our extensive data sets on local river health collected by our volunteer Citizen Scientists as part of the River Health Monitoring programmes that we run. (If you would like to get more involved in these please contact Jo Owens [email protected]).    

The app and survey are open year-round, so you can keep recording useful information about your local river at any time.
   

Here at The Ouse & Adur Rivers Trust, we are dedicated to protecting and enhancing our local rivers for wildlife and communities. We care deeply about our water environment, re-imagining the future of our wet landscapes, for all to enjoy.   

We would love to see what you get up to and what you discover.  
Please do send us any photos of you surveying your chosen stretch of river to [email protected]    

You can also share your photos on social media with #OART #BigRiverWatch.