18th May 2023

Riverfly surveying involves taking a sample from a riverbed and counting the types and numbers of tiny invertebrates. It is a way of checking for pollution incidents.

The Riverfly Partnership is a network of organisations working together to protect the water quality of our rivers, increase understanding of riverfly populations and conserve riverfly habitats. It runs the Anglers’ Riverfly Monitoring Initiative enabling volunteer groups to monitor the water quality of their rivers. Groundwork South is the Riverfly Group Coordinator for the Colne Valley Regional Park, supporting volunteers to monitor the River Colne and its tributaries.

Why Riverflies?

Riverflies are effective biological indicators for monitoring water quality as they are sensitive to pollution, fairly localised and live long lives as larvae on the riverbed. They are often referred to as our ‘river canary’ as their populations are affected by multiple factors such as habitat diversity, flow rate, water level and water quality. There are 8 riverfly indicator species we look for in surveys including Mayfly and Caddisfly.

How monitoring helps improve our rivers:

  • Alerts statutory agencies to investigate severe changes identified in water quality.
  • Produces long term biological data.
  • Acts as a deterrent to polluters.

Why we need volunteers

Riverfly monitoring is citizen science scheme which relies on local volunteers to carry out monthly surveys to build up a picture of our rivers and monitor changes to the water quality. We are looking for volunteers to monitor sites on the River Colne in Watford & Rickmansworth. No knowledge or experience is necessary as training will be provided.

What does volunteering involve?

  • 1 day training session to learn how to carry out a survey.
  • Survey your site once a month in a pair or group by taking a riverbed sample.
  • Identify the invertebrates collected using an ID sheet.
  • Record and upload your findings.
  • Meet new people, spend time in nature and learn a new interesting skill, all whilst helping to protect your local river.

How can I get involved to monitor my local river?

Sign up to hear about upcoming Riverfly Taster Sessions & Training Days and how you can become a riverfly monitor in your local area. Email our Group Coordinator, Lara to find out more: [email protected]

What our Riverfly Volunteers Say

‘Becoming a riverfly volunteer has helped me to connect with my own river, its wildlife, and the conservation issues close to home.’

‘Riverfly is a relaxing, enjoyable task that has a real impact.’

‘Being part of this citizen’s science project has been enjoyable and very satisfying. It has really opened my eyes to the diversity of invertebrate life that exists on the riverbed. Knowing that the data we collect could warn of a pollution incident makes our endeavours feel really worthwhile.’

‘Riverfly monitoring is an accessible form of citizen science, and I was attracted to it to help play a part in improving water quality and finding out about invertebrate life in the Colne. I have enjoyed getting out in the fresh air, wading in water and making new friends with similar interests.’