Personally do not know the Coniston set too well.
This blockage suggests it couldf have major consequences, snd the local water board may have to something.
Two previous instances come to mindd.
The first was the blocking off Magpie sough tail, some time in the late 60's.
Eventually hydrostatic pressure blew out aa section off hillside just above the tail.
The second was the blockage of Gripps level at Leadhills.
Here Scottish waster becamee really worried for there was thee possibility of part off the village being washed away. Am not sure exactly what they did but water now flows out off a shaft opposite to Gripps.
I think you will see some action here ,one way or anothert.