WaterBlitz of the Ravensbourne Catchment

Booking information


Up to 200 people


Date of WaterBlitz: Tuesday 30th May 2023

Time of WaterBlitz: 10am - 2pm

All equipment, sampling bottles and PPE will be provided by Thames21.

Thames21 staff will be stationed at locations across the Ravensbourne Catchment for volunteers to collect and drop off water sample bottles.


A WaterBlitz is a water sampling event that helps provide a snapshot of pollution issues across a river's catchment area.

This event is for local people and citizen scientists to take water samples of points of interest to them across the Ravensbourne Catchment (which includes the Ravensbourne, Pool, Chaffinch Brook, The Beck, Quaggy, Kyd Brook) to identify ongoing pollution issues impacting the catchment's water quality. This event will also be an important opportunity to sample areas in the catchment that generally have relatively good water quality to understand how poorer quality stretches of our rivers could perform throughout the catchment in the absence of pollution challenges.

The location of the Ravensbourne Catchment is shown on the map on this page.

Volunteers who register by 16th May 2023 will be provided with an online training session on Microsoft Teams on:

Thursday 25th May 2023 at 7pm

During this training session, volunteers will be able to select sites that they wish to survey, and these will be integrated onto a working map for all to access to avoid duplication of survey sites.

If you know where you wish to sample, please email Philly Nicholls at philippa.nicholls@thames21.org.uk with a location of your proposed sampling site (a dropped pin on Google Maps, National Grid Reference, what3words or GPS coordinates). Please note that to help us understand the catchment as a whole, your suggested sampling site may have been taken already by another volunteer; therefore we will try to accommodate you as nearby as possible to your sampling area but we can't guarantee that your original site will be available to sample.

On the day

On the day of the WaterBlitz on 30th May 2023, volunteers will visit the closest Thames21-staffed station in the catchment to them (this will be confirmed closer to the date) and will take water sample bottles and other necessary equipment before going to their agreed sample location and taking a water sample. These samples, and all other equipment taken, will then be returned to the same Thames21 station.

If you feel comfortable, please take pictures of yourselves sampling during the event and send to Philly Nicholls at philippa.nicholls@thames21.org.uk! Or post to Twitter and please tag @Thames21, @RavensbourneCIG and @EnvAgency.

If you are a trained Riverfly Monitoring Initiative (RMI) volunteer, this is a great opportunity to understand how water quality issues such as road run-off and sewage misconnections impact aquatic invertebrate communities. Undertaking an RMI survey at your WaterBlitz water sampling location with at least one other person will help us to understand how different types of pollution impact the diversity of Riverfly. So please email Philly Nicholls at philippa.nicholls@thames21.org.uk if you are interested in this.

What happens next?

Your water samples will then be sent to an accredited laboratory for analysis. Your results will be reported back to you by Thames21 in the form of an interactive online ArcGIS StoryMap (for example, see this one produced for a WaterBlitz event in the Brent and Lea Catchments in October 2022: https://storymaps.arcgis.com/stories/8811ce9a5a844440a928afc6c6bbac6e).

Samples from sites with poor water quality will be reported to the Surface Water Outfall Programme (SWOP) Team at Thames Water and raised with the Environment Agency and your local council.

Let's tackle pollution together!

Where's this event hosted?


Ravensbourne Catchment, All over the catchment (so Lewisham and Catford etc - not just Bromley), BR1 1AA

Where it's happening:

Ravensbourne Catchment