Riverfly Monitoring is our flagship citizen science project. Our volunteer monitors sample river bugs throughout Bradford and the Dales to assess the effects of pollution on life in the river.
Riverfly populations are one of the key indicators of long-term river health problems, as the insects living in the river fall quickly if pollution is present and take a long time to recover after a pollution event.
Our monitors work in pairs along the rivers and becks to sample an allocated site once a month during Spring and Summer.
To sample a river, volunteers kick the river bed for 3 minutes to release bugs from the gravel so they wash into a net. Hand-sized stones are then turned over for one minute to check for insects that cling to surfaces.
The monitors then sort and count the sample looking for 8 groups of bugs (see left).
The results are logged on the National Riverfly Monitoring Partnership website for approval by our local coordinator. Where problems are found, the results are sent to Environment Agency staff for investigation.
We are currently conducting Riverfly Monitoring in much of the Upper Aire, River Worth, and Middle Aire, as well as all the Becks that run into these stretches of river, and are planning to extend further downstream into Leeds.
We have a large number of Riverfly Monitors working in pairs from Gargrave to Apperley Bridge alongside a number of volunteers who work in bigger teams known as “Monitoring Hubs”, each of which sample their local beck.
The green pins show the location of sampling points as at June 2025
Riverfly sampling is a long term data gathering process that measures the change in river bug populations over many years. Our riverfly sampling process is still young with only a few years of data gathered during the growth of our sampling network. 2024 was the first year our volunteers gathered enough data to produce a catchment wide summary of our rivers health.
Click on the chart below for details of our findings so far.
You can also view the national database of all Riverfly records on the Riverfly Partnerships interactive database - click below
In 2025 we are recruiting new volunteer Riverfly monitors associated with local environmental groups who are able to monitor rivers in North Leeds in the following catchments:
If you would like to explore how you might get involved, please click the button below, which will take you to our detailed recruitment page, which gives details of where, when, and how we recruit, train and support our Riverfly Monitors.
We have developed a range of materials to help our trained monitors with their sampling.
Click this image to access those resources.
