Back in 2020 when Natural England and the Environment Agency discovered high levels of polluting phosphates in the Stodmarsh Lakes just outside Canterbury they put a stop to all planning applications in the catchment area, which included local authorities in Dover, Ashford, Maidstone and Canterbury. This had the effect of creating a massive back-log of stalled planning applications as can be imagined. https://thecanterburyhub.co.uk/snowball/stodmarsh-whats-the-solution/
There are plans afoot to create a giant 'reed-bed' in the Stour Valley to mitigate the pollution, with the local authority then 'selling credits' to developers unable to mitigate their own schemes on site.
Until the local authority scheme is ready, Natural England are preparing to issue their own credits - see links below for updates:-