The council has been monitoring the situation and has sought advice from experts and organisations to assess the wellbeing of the lake's fish population and consider possible short-term measures.
While water levels are currently low, observations indicate that conditions are not significantly different from those experienced during previous hot summers. Seasonal fluctuations in lake levels are a recognised feature of Pells Lake and recent ecological investigations may help explain why these changes occur.
As part of the council's ongoing programme to improve the long-term ecology of the lake, the first stage of survey work was completed last week. This involved analysing the volume and composition of the lake's silt. Initial findings suggest that Pells Lake is likely to be a natural depression sitting within the water table rather than a lined water body which would account for seasonal variations in levels.
The council has consulted the Environment Agency, local fisheries specialists, Mayfly Aquacare and other relevant organisations. Expert advice indicated that relocating fish is not a practical long-term solution as the process would involve extensive health checks and carries risks of disease transmission. Specialists have also advised that the stress caused by relocation can itself result in fish mortality.
Advice received confirms that the carp commonly swim near the surface during warmer weather which can sometimes be mistaken for signs of distress. Fish experiencing genuine oxygen stress would be expected to show more obvious signs including gasping for air at the surface.
A range of other potential mitigation measures has been investigated including the installation of aeration equipment and adding water from external sources. However these present practical and environmental challenges including power supply requirements, security concerns, water quality issues and the risk of introducing disease.
The most practical short-term measure identified is the continued addition of water from the Pells Pool borehole supply. This has already been arranged and is being done by the pool management team.
Cllr Matthew Bird, Chair of the Buildings and Amenities Committee said: "We are aware of the challenges we face and will continue to face as climate change impacts our building and open spaces. The measures we take at Pells form part of our developing climate resilience responses. Residents can be assured that the health of Pells Lake remains under active review.
"Lewes Town Council remains committed to its longer term ecological improvement programme helping to enhance the health and resilience of the lake for wildlife and the wider community."