If that report was today, seems very odd as we’ve had very little/no rain to fill rivers in April.....?
It was, and still is. I thought I'd found an explanation, based on it being a very high spring tide and Looe the most-flooded town in England. But it's past high tide now, and
GWR▸ are still saying:
09:05 Looe to Liskeard due 09:33
09:05 Looe to Liskeard due 09:33 will be cancelled.
This is due to a river flooding the railway.
Additional Information
The railway is flooded at Sandplace. Network Rail staff are expected on-site at 08:15, and will advise whether the subsequent trains to and from Looe are able to run.
That looks more like something local, like a blocked stream or drainage channel.