
Understand our results
The data the project collects is vital in our fight to save the River and its catchment. Find out how.
The Chess Smarter Water Catchment project is collecting a range of data from its initiatives, including information about water quality, water vole populations, and results from citizen-science surveys. As we progress with our work, we will provide feedback on this data for our volunteers, stakeholders and the public.
Providing a baseline
Produced in the first year of the Chess Smarter Water Catchment project (March 2021 to March 2022), the State of the River Chess is a baseline report for the Chess catchment. This desk-based study provides an understanding of where we stand with regards to each of the project’s six themes: improving water quality; managing flow; improving wildlife corridors; managing invasive non-native species; working together; and involving people. The document also provides an opportunity to engage with people in the catchment and inspire action for the Project as we move into the future.
We will be able to repeat this study within the Project term (10 years) to see if there have been any improvements as a direct result of the investment we have put into the catchment, or if the River Chess and its catchment are still degrading.
Water quality in the River Chess
As part of the Chess Smarter Water Catchment project, we have placed sondes (multiple sensors) into the River Chess to give us live 15-min interval information on its water quality characteristics, including turbidity, pH, electrical conductivity, nitrate, dissolved oxygen and ammonia concentrations, water level, and temperature. We are currently analysing the data we have collected from this initiative, gaining a clear understanding of the current water quality of the river. This will, ultimately, highlight any dangers or threats, making it possible to devise on-the-ground actions for improving the water quality of the Chess.
The project’s citizen scientists are also assisting in the assessment of emerging contaminants in the River Chess. This involves taking a sample of river water from different locations along the Chess and sending them to Imperial College, London, to be analysed. This information will be vital in understanding the concentration of certain chemicals and any potential risk they pose to wildlife.

Volunteer Hefin with the technical dashboard he has created for the River Chess
Water flow in the River Chess
In spring 2022, more than 40 enthusiastic volunteers signed up for training in survey techniques, such as MoRPh (Modular River Survey), which is an excellent tool for monitoring changes in river channels and riparian buffers. More than 60 hours of surveys have already taken place – and more are planned – across two different stretches of the River Chess at Restore Hope Latimer.
The first survey location is a reach on the main River Chess. This is the site of a restoration scheme aiming to reduce shading to encourage in-stream and bankside vegetation, increase the variation in flows within the channel, and increase the suitability of habitat for water voles. Surveys before and after restoration work help us to evaluate the effectiveness of the works.

The second survey location is on the Little Chess where the River Chess Association have been introducing in-channel deflectors over several years to increase flow variability. The Chess Smarter Water Catchment project has also funded new fencing work along this stretch of river. Previous water vole surveys have shown that there is a healthy population here, and that they could benefit from an expanded area of suitable river habitat. We are closely monitoring this area using MoRPh and water vole surveys to record the habitat that is developing around the deflectors, to see how the new fencing alters the riverbank vegetation over the coming years, and to understand if there are positive outcomes for water voles in the area.
Monitoring River Chess Wildlife
The Chess Smarter Water Catchment project is monitoring wildlife along the River Chess and in its catchment to understand how it is responding to threats and challenges, and how conservation works may help to restore it. SmartRivers is one of the surveys we are using. Citizen scientists are helping to collect samples and data on riverfly communities. These insects spend most of their lives in the water as nymphs, making them excellent indicators of river health. Their continuous exposure to water makes examining them incredibly informative regarding the build-up of contaminants.
2022 survey results:
Our first results show that May was a good month for riverfly communities with only a few areas of the Chess seeming to be suffering from critical pressures. Let’s hope this result is maintained when reassessed in the autumn!
Water voles are another key indicator species, and one the project is aiming to protect. Water vole surveys have been undertaken every two years along the Chess since 2001, and we are continuing to conduct surveys to understand where their populations are, how they are doing, and how they respond to conservation works.
2021 survey results:
Results from 38 surveys carried out on the River Chess and its tributaries between Chesham and Chorleywood showed water vole activity on 29 sections of the River. Results also showed that the population’s range had extended 1.5 km downstream from the previous survey in 2019. The number of water voles present was calculated from a detailed latrine count and results showed that the population had increased significantly from 2019. Water vole numbers are estimated at 92% of the 2001 population.
Read our latest Water Vole Report
Water voles
Water voles live on our waterways, burrowing into riverbanks and hiding among reedbeds. Spring is a great time of year to spot this fluffy, brown rodent as bankside vegetation will still be low. Look out for the signs that they are around: little piles of poo in ‘latrines’; stems of grasses chomped at a 45-degree angle; and a distinctive ‘plop’ as they dive into the water. If you spot one, take in their furry tails and blunt noses – most unlike brown rats, which they often get mistaken for. They are one of our most threatened mammals, having disappeared from more than 90% of their original habitats and now listed as Endangered on the IUCN Red List. They are extremely vulnerable to habitat loss and predation by the non-native American mink.
More about data collection in the Chess catchment
- Chess Watch is a partnership between the Queen Mary University of London, River Chess Association, Chilterns Chalk Streams Project and Thames Water. The partnership is monitoring water chemistry in the River Chess, increasing public awareness about the threats to water quality and river health, and providing educational materials about chalk streams and the links between water quality and water quantity issues in rivers.
- A Natural Capital Assessment – a project to collect data on the extent, condition and change in ecosystems, natural capital, and the benefits to society – is being undertaken in the Chess catchment. Baseline data has been complied to provide evidence for the issues and challenges in the area.
Tracking the Impact
Tracking the Impact is a four year landscape-scale wildlife surveying programme across the Central Chilterns area, which has been further expanded in 2023 to include the Chess catchment area.
In 2022, our 78 volunteers submitted over 3,250 records between them, recording 335 species – with each record helping us to better understand the wildlife of the Chilterns.
All of the records for the survey squares have been entered onto our new online interactive map so you can see for yourself what birds, butterfly and plants have been recorded and where.


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