By ALEX CHRISTIE-MILLER
Water quality in the Bure River which flows past Aylsham is “pretty good” according to findings by Bure River Action.
But there may be a bigger threat to the river – the invasive signal crayfish.
The group has been testing the river since January as part the National Trust’s Riverlands project, which involves conducting weekly testing of the water for phosphates and ammonia at four locations: Dunkirk Meadows in Aylsham, at the Burgh-next-Aylsham footbridge on the Bure, and on the Mermaid at Marsham and Burgh.
“What stands out overall is that these figures are pretty good,” said Alex Christie-Miller, who has been carrying out the monitor along with BRA chairman Chris Williams..
“Although they don’t tally with many people’s anecdotal observations of the river’s health over the past few years, it is good to know that these pollutants are not the cause of the river’s current problems.”
| Pollutants | Dunkirk | Burgh | Mermaid (Marsham) | Mermaid (Burgh) |
| Phosphates (mg/L PO4-P) – Range | 0.03-0.12 | 0.01-0.14 | 0.00-0.12 | 0.00-0.10 |
| Phosphates (mg/L PO4-P) – Average | 0.051 | 0.058 | 0.046 | 0.025 |
| Ammonia – Range | 0.00-0.07 | 0.00-0.07 | 0.00-0.21 | 0.00-0.09 |
| Ammonia – Average | 0.005 | 0.013 | 0.077 |
0.022 |
Over eight months of weekly testing, the Bure was found to have average phosphate (PO4-P levels of 0.051mg/l at Dunkirk, and 0.058mg/l at Burgh. The Mermaid had 0.045mg/l at Marsham, and 0.05 at Burgh. The equivalent figures for ammonia were 0.005, 0.013, 0.077, and 0.022mg/l respectively.
The data shows that the level of pollutants in the river are firmly in the ‘Good’ or ‘High’ ecological range for phosphates. Only ammonia levels in the Mermaid at Marsham go above that level.
The Mermaid is significantly cleaner at Burgh than at Marsham, which may be due to stream restoration work done upstream of Burgh a few years ago by the Norfolk Rivers Internal Drainage Board, which is helping clean the water.
Alex added that the data did not show a significant impact from the Aylsham Sewage Works, but the testing regime and distances from the outflow meant specific pollution events may not have been detected.
“The work of the National Trust in the Bure catchment upstream of Aylsham, may also be having a positive effect.”
Alex and Chris believe other chemicals released in treated sewage or from other sources may be harming the river, and also suspect invasive signal crayfish may be playing a role.
“These directly affect invertebrate populations and cause excessive turbidity (which suppresses plant growth) by burrowing into the river banks, which they erode over time.”
Chris, from Aylsham, and Alex, from Burgh, helped form BRA in 2024 and are committed to gathering this data to offset reduced monitoring by the Environment Agency.
The EA’s own river testing has dropped dramatically in the past decade, falling nearly 60 per cent between 2012 and 2021.
“Gathering this data now is also crucial in the context of the future expansion of housing in Aylsham, since it will provide a baseline against which we can measure any impact that new developments may have on the river,” said Alex.
Chris and Alex would very much like to receive funding for more testing equipment and reactants to expand and would appreciate other people joining as regular volunteers. Currently, the weekly testing takes between 2 to 3 hours to complete (1 hour for gathering samples, 1 to 2 hours for testing).
Anyone interested in getting involved can email connect@bureriveraction.co.uk.
