
Water Testing Programme
Empowering Volunteers across the catchment to Protect Water Quality
River Mole River Watch launched an ambitious water quality testing programme across the River Mole catchment area in May 2023.
To date we have recruited and trained over fifty dedicated volunteers. Working with our volunteers we identified 32 suitable and safe test sites both on the main river and the tributaries all the way from the source of the River Mole in Crawley to the confluence with the River Thames at Molesey. Every month the volunteers collect water samples, test and report their data and observations. The initial focus of the testing program lay in assessing phosphate levels using Hanna Low Range Phosphate Checkers. Phosphate is a useful indicator of pollution from agricultural and sewage treatment plants. We have now broadened our testing parameters to encompass additional essential measures including nitrate, ammonia, conductivity and water temperature.
At over 80km in length and covering an area of 450 square kilometres the comprehensive coverage of our river catchment by volunteer testers is a huge success story!





Efficient Data Collection and Analysis
To streamline data collection, we have developed a mobile survey app. Every month our volunteers record water quality test measurements and observations of river health on the app at their river test site. In addition, they record river flow and level and other conditions such as weather and known pollution discharges.They also monitor for visible signs of pollution, such as dead fish or excessive algae growth, as well as indications of contamination through smell or plastic waste. In addition, volunteers diligently record the river level, weather conditions, and any instances of upstream sewage spills within the previous 48 hours.





The data collected from each stretch of the river is is recorded on the app. It is aggregated and analysed, providing a comprehensive overview of the entire catchment area and allowing us to see hotspots of pollution. From the data we have collected we are already seeing emerging patterns.




Expanding the Scope of Testing
We are working with South East Rivers Trust to develop a county-wide testing programme covering more catchments. This multifaceted approach will provide a more holistic understanding of the river health across the Mole Catchment and beyond. In the future we might include testing pH, turbidity and dissolved oxygen. Another addition would be taking part in a kick sampling programme which collects and counts a specific group of indicator water invertebrates, the range and quantity give a very good idea of the health of the water. Some species are more tolerant of pollution than others
A Collaborative Network
We are building a valuable body of evidence which we are using to engage in ongoing discussions with key stakeholders such as Thames Water, the Environment Agency, farmers, and other polluters and custodians of the river. River Mole River Watch exemplifies the power of citizen science and the remarkable impact that a dedicated group of individuals can have on protecting our natural resources with the help of partners such as South East Rivers Trust. By presenting citizen science data, River Mole River Watch aims to raise awareness, influence policies and drive positive change in river management practices.
Through our water quality testing program, our wonderful volunteers are fostering a sense of environmental stewardship and initiating conversations with key stakeholders and the wider public to safeguard the River Mole's flow and ecological balance for future generations.
If you would like to find out more about our water testing programme, or volunteer please contact us.