FreshWater Watch archive
The Bristol Avon WaterBlitz: what volunteers measured, 2016 to 2022
This address: freshwaterwatch.thewaterhub.org once held the Bristol Avon WaterBlitz results map from FreshWater Watch, Earthwatch's citizen science programme. The event is run by Bristol Avon Rivers Trust, now as RiverBlitz; this page is The Water Hub's own summary of the published results.
The Bristol Avon WaterBlitz was a week each summer when volunteers sampled rivers, streams and ponds across the Bristol Avon catchment for nitrate and phosphate, run by Bristol Avon Rivers Trust with Earthwatch's FreshWater Watch from 2016; average nitrate ran between about 3 and 4 mg/L each year, and the trust now runs the event alone as RiverBlitz.
Year by year
The first WaterBlitz ran in 2016 as part of the Festival of Nature, with phosphate and nitrate samples taken all over the catchment (Bristol Avon Rivers Trust, 2016). The table gives each later year as the trust reported it: the averages for 2017 to 2019 are read from its results infographics, and in 2022 the trust reported shares above a threshold rather than averages.
| Year | Dates | People | Samples | Nitrate | Phosphate |
|---|---|---|---|---|---|
| 2017 | 10 to 16 June | 375 | 176 | average 4.2 mg/L | average 0.1 mg/L |
| 2018 | 23 to 29 June | 260+ | 120 | average 3.1 mg/L | average 0.16 mg/L |
| 2019 | 1 to 7 June | 424 | 164 sites | average 3.78 mg/L | average 0.197 mg/L |
| 2021 | 9 to 16 July | 193 | 239 | average 3.23 mg/L | average 0.128 mg/L |
| 2022 (RiverBlitz) | summer | 87 | 143 | 70% high (over 2 mg/L) | 70% high (over 0.1 mg/L) |
What the results showed
The 2019 results found pollutant levels high in many parts of the catchment and either consistently high or rising over the previous three years; 46% of samples showed high nitrate and 45% high phosphate that year, 77% of samples were colourless and litter was seen at 8% of sites, against 4% in 2017 (Bristol Avon Rivers Trust, 2019). In 2021, 55% of samples were medium or high in phosphate (Bristol Avon Rivers Trust, 2021). The thresholds moved between years, the 2019 page calling nitrate over 1.0 mg/L high while 2022 used 2 mg/L, so compare averages rather than shares.
Who ran it, and RiverBlitz
Bristol Avon Rivers Trust ran the WaterBlitz in partnership with FreshWater Watch, funded in 2017 by the Bristol Avon Catchment Partnership and the Greggs Foundation (Bristol Avon Rivers Trust, 2017). The trust later renamed it: WaterBlitz is now RiverBlitz, and the trust decided to go it alone (Bristol Avon Rivers Trust), so its own site is where to find the next event. The 2016 results, 95 points, are still published as a public map layer.
Testing the water at home
The nitrate a river test measures is the one that matters in a well: the US limit for public drinking water is 10 mg/L as nitrogen (EPA), and a private well's owner is the one who tests it. Our answers on removing nitrate from water and home water test kits cover what a household can do.
Next: water testing services compared on The Water Hub.
Questions
What is the Bristol Avon WaterBlitz?
A week each summer from 2016 when volunteers tested water across the Bristol Avon catchment for nitrate and phosphate, run by Bristol Avon Rivers Trust with FreshWater Watch.
What did the Bristol Avon WaterBlitz find?
Average nitrate of about 3 to 4 mg/L each year and pollutant levels high in many parts of the catchment, either steady or rising from 2017 to 2019.
Is there still a WaterBlitz on the Bristol Avon?
Bristol Avon Rivers Trust runs it on its own now, under the name RiverBlitz.
Sources
- Bristol Avon Rivers Trust: the 2016 Water Blitz, read 2026-10-21
- Bristol Avon Rivers Trust: WaterBlitz 2017, read 2026-10-21
- Bristol Avon Rivers Trust: WaterBlitz 2017 results, read 2026-10-21
- Bristol Avon Rivers Trust: WaterBlitz 2018 results, read 2026-10-21
- Bristol Avon Rivers Trust: WaterBlitz 2019 results, read 2026-10-21
- Bristol Avon Rivers Trust: WaterBlitz 2021, read 2026-10-21
- Bristol Avon Rivers Trust: RiverBlitz 2022, read 2026-10-21
- Bristol Avon Rivers Trust: WaterBlitz is now RiverBlitz, read 2026-10-21