Donate Online How to take part in the Water-Blitz

Registration is now open for the 2nd October Thames WaterBlitz. Previous and new volunteers must go to to register for the next event. There is information and a video about how to register, record and enter data, and download the app.
Registration will be closed on 25th September to allow time for us to post out your free test kits.
Kits will be sent out after you have registered (even if you’ve done this before!)when you enter/update your address
Look out for the Freshwater Watch email address when you register

Where will you take your samples?

You can look at last year’s result’s to identify sites that have been tested in the past. We encourage you to find new sites (different types of sites) that you can conveniently test again at the next water-blitz, so preferably ones that don’t normally dry out in summer, you have any necessary permission to access and can so safely.

You will need to accurately record your sampling location. You can either do this by hand, using an Ordinance Survey map (if you need help with this go to, use a smartphone to determine your latitude and longitude, or the online map service on the FreshWater Watch website. Alternatively use to get your grid reference and other location information.

What will you record and how?

There are excellent guidelines on health & safety, and how to collect water samples and use the test kits on the Freshwater Watch site, which you will be able to view after you’ve registered. Collecting the water sample doesn’t involve wading into water of any depth – a variety of collecting methods can be used, ranging from a small bucket on a rope to a plastic bottle taped to a stick. A telescopic decorating pole works very well (with a small plastic container on the end), compact but providing the range needed for different sites. The P tests take 5 minutes to react, the N test 3 minutes. Timing is critical, so make sure you have a watch or phone with you.

As well as taking P and N readings you will need to record the location, a site name, the date, time, number of participants, type of freshwater body and some observations about the appearance of the water and its surroundings. If you can take a photograph as well that’s a bonus! Water-Blitz sampling is allowing us to better understand ponds or lakes, or stretches of flowing water that are consistently clean or consistently polluted highlighting where potential pollution sources may be located. From a management point of view, participants have reported high sediment, high nutrient or algal bloom conditions in a number of projects that have resulted in agency actions towards mitigation.

All this data can be recorded and uploaded directly using the ‘phone app (available on the Freshwater Watch website). However we strongly advise you to keep a paper copy as well, so you have a personal record of your data and a back-up in case of mishaps. Forms can be downloaded from the Freshwater Watch site.

Have fun, stay safe and thank you for taking part