Sonning Common Parish Council has been monitoring the pond for several years after residents first noticed the water level was lower than usual in November 2024.
Chair Vicky Boorman said “It’s much lower now, at this time of year, than we would expect it to be with recent rain.
“People have always taken their children there to feed the ducks, so in living memory, this is an unusual situation.”
After six carp were found dead in the pond in June 2025, the council arranged for treated water from Thames Water to be pumped into it.
The council then commissioned an independent hydrological survey from Water Resource Associates, to try and find out the cause of the diminishing water level.
Its report, in December 2025, concluded that after construction of the adjacent retirement village began in November 2023, the pond water level fell and did not recover in the 2023/24 winter.