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  • Simon Collins

Celebrating success and new plans, projects and partnerships this year: Our AGM.

Our first Annual General Meeting last weekend reviewed the remarkable progress we have made in River Mole River Watch over the last 12 months. We also outlined the exciting plans, projects and partnerships rolling out in the year ahead. We welcomed new volunteers as well as celebrated the success of our fantastic existing citizen science team. Here's a summary of what we covered in the well attended, busy meeting:

Progress so far

Our aim has been to drive action to restore the streams and main river of the Mole Catchment to a healthy condition for wildlife and for people. We are keen to work with others and aim to build constructive working-relationships with all who are concerned about the river and all who have the ability to contribute to improving river health. We aim to raise public awareness of the importance of a healthy river system and the threats to its health. We are data-driven, believing that we will have most influence if we can support our campaign with robust evidence which cannot easily be challenged.

Raising Awareness

We have made great strides towards raising public awareness of the issues threatening our beloved River Mole, not just locally but also in national news media – contributing to the ever-growing calls for action from other river groups, celebrity campaigners and some politicians and their political parties.

We are active on social media. Our trustees have given talks to many local groups and have given interviews on radio and to the written press. We are piloting talks for schools. Much of the attention has been directed at sewage overflows but many in our local communities are also concerned about the impact of new developments on the inadequately performing sewerage system and on flood risk.

Citizen Science

Perhaps our biggest achievement so far has been to organise a full programme of citizen science water quality testing. Every month our volunteer citizen scientists carry-out Catchment-wide water quality monitoring with results collated and displayed here on our website. To date we have concentrated on measuring phosphates using Hanna Phosphate checkers, a more precise technique than indicator strips. Phosphates are an effective indicator of pollution from human sewage, treated and untreated, from treatment works, overflows, leaks and domestic misconnections. Phosphates also derive from agricultural sources including animal waste and phosphate-rich run-off from fields, usually the legacy of decades of over-application of fertilizers.


The data collected by volunteers demonstrates clearly the potentially damaging effect of inadequately treated sewage particularly from small treatment works which discharge into small tributary streams which show consistently high pollution levels. The data also shows the impact of the seasons. In winter, pollutant quantities almost certainly increase but the impact on the river system is reduced by dilution. However, it is in summer that we see the highest phosphate concentrations with several streams and parts of the main river rated ‘Poor’ or even ‘Bad’. This is the time when the eco-system is under the most stress due to high temperatures, low water levels, and low levels of dissolved oxygen.

Our research also shows a number of poorly performing sewage works in the catchment as illustrated above by the duration of storm overflows. A major focus this winter has been on the failure of the Horley treatment works. Here we campaigned to hold Thames Water to account for the appalling sewage flooding adjacent to residential areas and forming a public health hazard in recreational areas.

Our collaboration with West Vale Residents Association and local councillors has yielded notable success in forcing Thames Water to at least partly mitigate this unacceptable long term pollution problem from a neglected sewage works that has clearly lacked the investment. This, and other campaigns are ongoing.


Two of our trustees are members of the Mole Catchment Partnership Steering Committee, actively contributing to Catchment management decision-making. Other members of the Partnership include South East Rivers Trust, Surrey Wildlife Trust, the Environment Agency, Thames Water, SES Water, Natural England, river users and, we hope soon, landowners. We are members of the Catchment Partnership’s Water Quality Monitoring Sub-group, seeking to develop the most effective citizen science water quality monitoring programme under the leadership of the South East Rivers Trust.

We are proud to have been invited to be partners with the South East Rivers Trust in their Mending the Upper Mole Project. In August we were very pleased to be one of the three short-listed finalists in the ‘Emerging Talent’ category at the Surrey Wildlife Trust’s Community Champions Awards celebration.


Our numbers have grown significantly over the year, particularly since our web-site was launched. We have 30 volunteer citizen scientists carrying out water quality monitoring and more than 200 members registered via our web-site. Many of these members have said they are willing to be involved in practical projects and we plan to invite them to join specific projects starting at this AGM.

New Projects for 2024-2025

We have a number of exciting new initiatives rolling out this year including:

  • Enhanced water quality monitoring testing using as Hanna Ammonia checkers and Conductivity meters.

  • Tributary Surveys: a mapping project to identify issues across the catchment

  • Partnerships and projects with SERT and SESW

Our partnership with South East Rivers Trust (SERT) has proved to be extremely helpful with several projects designed to both assess the status of the river and lead to improvements in the quality of habitat.

The SERT Mending the Upper Mole Project is targeted to improve tributaries in the Upper Mole including the Gatwick Stream.

Our volunteers are high resolution testing monthly on the Upper Mole as part of the Mend the Upper Mole project with the project aim to deliver real improvements to the Gatwick Stream and other tributaries in the sensitive Upper Mole catchment.

Working with South East Rivers Trust we are soon to be offering training in Outfall Safaris to identify potential urban pollution sources by mapping outfalls. We will be also be training volunteers in RiverFly invertebrate monitoring which directly assesses river ecosystem health.

Our own River Mole River Watch Tributary Survey project endeavours to map the entire catchment to identify pollution sources, barriers to fish and land use issues to gain a deeper understanding of river pollution.

SES Water Nitrate Testing Project

We are proud to have been trusted with the opportunity to support SES Water’s nitrate monitoring initiative where, we believe in a first-of-a-kind in the country, we will use Hanna monitors to assess nitrate in our river water.

Rising nitrate levels in groundwater aquifers

Nitrate is a particular concern for SES Water as it has the potential to migrate through the permeable chalk bedrock and contaminate the aquifers which supply over 80% of our drinking water locally. Nitrate levels have been increasing over the years in our local groundwater so SES Water is conducting a major study into nitrate pollution because addressing the source of nitrate is better than costly removal treatment.

Our volunteers will be collecting monthly data on nitrate levels using the method outlined at the meeting shown below in this clip.

The data our citizen scientists provide SESW over the next two years will be critical in their research.


This Summer, we are looking forward to working with both a Masters student and Undergraduates from the University of Reading. They will be researching the distribution of coliform bacteria upstream and downstream of a sewage treatment works discharge and research into links between river pollution and weather.

Support and Funding

The Treasurer's Report outlined our healthy budget moving forward. During the year we have received grants and donations from a number of organisations and individuals for which we are very grateful. We have just gone live on a Just Giving page. Our largest expenditures are in water quality monitoring equipment. We have already purchased Hanna ammonia checkers which are being distributed to our volunteer citizen scientists.

Challenges ahead

Overall, it has been a highly successful first year although, of course, many challenges remain. The more we learn, the more it becomes very clear that it is going to take many years of effort and major investment to restore our river system to a healthy condition. We know Thames Water, our sewerage company, is in perilous financial condition. We know from our meetings with Thames Water personnel and through site visits that many of their facilities are in poor condition – unable to perform reliably to deliver what their current operating permits require, let alone achieve real improvement in the quality of treated sewage discharged to the environment. There needs to be wider adoption of Catchment-Sensitive Farming as promoted by Natural England. Also natural-flood management schemes are needed in more locations to "slow-the-flow" and reduce volumes of waste water overwhelming treatment works. Issues such road-run off and “forever chemicals” are huge pollution issues still to be addressed. Domestic misconnections continue to damage many smaller streams despite the efforts of Thames Water to identify offending sources.

Through the team effort and partnerships forged by groups like ours, we have an important role to play in highlighting issues, holding polluters to account and driving action. Thank you to everyone who has helped us over the last year: our volunteers, our supporters and our members. Thank you to all who have contributed funds for our work including county and local councillors. We are hugely grateful for all your support.

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