About pond water monitoring
Monitoring the water quality of Jersey’s ponds is important because it:
- allows us to compare water quality across different ponds
- helps us to assess if the habitats are in good condition, which supports species conservation and habitat protection for the future
- shows seasonal changes which can show us the potential impacts of climate change
- gives us baseline data to monitor long-term trends
- allows us to detect problems early and reportpossible pollution incidents that need investigating
Ponds in Jersey
Ponds are found all over Jersey, however we monitor those on Government or National Trust land, in sensitive environmental areas.
By checking the water quality, it helps us to better understand how different conditions affect the plants and animals living in these ponds. This information helps us manage Sites of Special Interest (SSIs) and supports conservation work. This includes protecting species such as the Agile frog.
Ponds currently monitored
- Grosnez
- Canne du Squez
- Beauport
- Woodbine Corner
- Somenos
- Ouaisne North Slack
- Ouaisne Pond
- Noirmont
- Grouville NT pond
- Grouville Lagoon 1
Both Ouaisne Slack 5A and Les Creux North were only monitored from 2024 to 2025.
Setting standards
There are no official standards for checking pond water quality yet, however the development of pond specific standards is being considered as the awareness of pond importance becomes more apparent.
In the meantime, to help make sense of the results data is compared with EU Water Framework Directive standards for lakes. While not pond specific or legally required in Jersey, these standards provide a benchmark and helpful guidance for maintaining good environmental quality.
Learn more about
the Water Framework Directive on the European Commission website.
How our pond waters are tested
We carry out monthly on-site chemical testing.
The data collected is outlined below.
Onsite field testing from 2024 to 2025
Below are a list of field tests carried out onsite:
- weather conditions
- appearance
- odour
- temperature
- pH
- conductivity
- percentage of dissolved oxygen
- alkalinity
Laboratory based testing from 2024 to 2025
Testing is carried out for the presence of the following chemicals.
- COD
- Suspended solids
- Ammonia
- Chloride
- Nitrite
- Phosphate
- Sulphate
- Sodium
- Potassium
- Magnesium
- Calcium
- Iron copper
- Manganese
- Arsenic
- Copper
- Lead
- Zinc
- Total phosphorus
Ponds waters monitoring report 2024
The water quality results are compiled in a report that summarises the 2024 findings. In future, reports will be created for each site separately. This will better support site specific management.
Water quality monitoring of ponds across Jersey 2024
Overview of the 2024 results
Most ponds are below the required Water Framework Directive (WFD) annual average for lakes. However almost all are impacted by heavy metals, nitrate and phosphorus to varying levels throughout the year. Details about parameters that are below and above their target level can be found on page 73 and 74 of the Water quality monitoring of ponds across Jersey 2024 report.
Water quality monitoring of ponds across Jersey 2024
Further monitoring over time, usually a six year period, will show if this is a short term or persistent problem and whether action should be taken.
gov.je