I was at my local River Cut to watch the Environment Agency restock the river, following pollution that killed a 1,000 fish in the summer. The river looked in perfect condition and has been fishing well despite the pollution, this 650 roach, dace and chub a top up to replace those lost.

The EA fish farm truck had arrived bang on time at 10 am from Calverton near Nottingham and was soon ready to offload the fish, while myself and another club member looked on. This is a UK wide service paid for by income from fishing license fees, being part of the wider fishery improvement work carried out by the agency.

The fish are carried in oxygenated tanks at a level of 300% of normal and were netted out into buckets, then introduced into their new home in the river.

When the fish had been stocked, the farm truck drove off to another destination, while my friend and I watched the fish spread out across the river. We then stood chatting at the outlet channel and were stunned to see a thick cream coloured solution pouring from one of the underground tunnels.

In minutes the river had been transformed from a clear flowing stream to an alien looking one.

I called the national EA Incident Line on 0800807060 and had an instant response, the information being relaid to local agency officers and Thames Water, who sent investigators to the scene. Fish were topping all over the river and we feared for the worst, but thankfully no fatalities seemed apparent.

Returning to the river four hours later, there were two EA officers taking river samples along its length, the upper section at the outlet where the pollution had entered now being clear, although a thick sediment was coating the bottom. Further down the river was still highly coloured.

Fearing that the fishing had been ruined, my friend Mick was on the bank the following morning for a test fishing session and his smile said it all, reporting a steady catch of gudgeon and roach from his favourite swim.

Panic over, but ironic that this often polluted river, should suffer again only minutes after receiving more fish. No doubt in time we will find out what and where this latest influx has come from and hope that there are no long term effects on the fishing.