Sandford Hydro

Following the significant fall in river levels in the Sandford reach on Sunday 29 May 2022, which resulted in damage to boats, we have been working with the Environment Agency staff and a marine expert, appointed by our insurers, to support investigations as to the cause.  

Low Carbon Hub is satisfied that the hydro was not the cause of the river level fall and subsequent rise and has submitted evidence demonstrating this to the Environment Agency.  

The hydro generators were not operational at the time of the incident as river conditions were not suitable for generation. Since the incident the hydro generators remained offline at the request of the Environment Agency and as a matter of good practice while the investigation continued. This also coincided with a prolonged period of low river levels, during which time the hydro would not have been operational.  

The investigation is now focused on the operation of the gates located on the weir.   

The Environment Agency operates the weir and manages river levels by raising and lowering gates on the weir. The Environment Agency approved a Permit for Low Carbon Hub to commission a project to install electrically powered ‘actuators’ on two of the gates. These systems enable the gates to be controlled remotely, and allow for easier control of the two gates, as raising and lowering is powered electrically rather than manually by hand crank.  The Permit was approved following extensive engagement between Low Carbon Hub’s expert contractor and the Environment Agency to ensure the design and implementation of the system met the Agency’s specification requirements. This project was in the process of being implemented. The project was paused immediately following the incident and will remain so subject to the Environment Agency’s process. 

The cause of the river level drop was likely due the inappropriate opening of one of the gates controlled by the new system.  

While the separate investigations by Low Carbon Hub, our insurers and the Environment Agency remain on-going, the Environment Agency has now given us permission to resume generation following submission of evidence demonstrating the independence of the hydro generators from the gate system and confirmation that the gate control system is not in operation.   

There remain a number of questions to resolve regarding the gate actuator, the control system and the specification of those systems and, the governance of the project. Whether, and when, the system is brought online will be determined by the Environment Agency.  Low Carbon Hub and TLS Energy, Low Carbon Hub’s operations and maintenance contractor for Sandford Hydro, will work closely with the Environment Agency to inform that process. Until then the actuators remain disconnected from electrical power and the gates will be operated only manually, as has historically been the case. 

Investors in Sandford Lock Hydro have helped return the Lasher Weir on the Thames to its historic role as a provider of clean energy. The hydro scheme generates a huge 1.6 GWh of renewable electricity per year, which is the equivalent demand for 500+ households — or most of Sandford!

The Sandford Lock hydroelectric plant uses three Archimedes screws (similar to the one currently in operation at Osney Lock Hydro) to generate electricity from the flow of the river water.

The hydro site has been through rigorous ecosystem surveys to ensure it has minimal impact on the local wildlife, such as trees, shrubs, birds and bats. It’s even beneficial for wildlife and biodiversity in the area, through the installation of a fish pass in the river. This is a system designed to encourage all the species in the river to travel upstream – the first time in 400 years this will have been possible.

Sandford Hydro has been a long labour of love from the local community. Community members directed the project tirelessly from its conception all the way through to setting up as a Sandford Hydro Community Interest Company. As the project grew, Sandford Hydro CIC decided to team up with Low Carbon Hub and hand over the planning and development to us. We were really excited to work with such a committed community to help see their vision through to the end.

Sandford Hydro was part of a community share offer, which means that members of the community and local residents own part of this amazing hydro system. The funds from the electricity generated will give a return to people who have invested in the hydro, as well as funding future community energy initiatives through Low Carbon Hub’s community benefit programme.

The Hydro was fully commissioned in August 2017. To see the full timeline of the project, head to the bottom of this page.

440 kW
installed capacity
1.6 GWh
annual generation of clean electricity
tonnes CO₂ emissions prevented every day
households supplied with clean energy

Many thanks to all who have played a part over the years in getting Sandford Hydro up and running; it is so satisfying to watch the screws in action and think of all that energy being harvested from the river.