The rate of rise in the Tilshead borehole groundwater level accelerated at the start of the week, following the heavy rain two weeks ago. This rate of rise is just starting to show signs that it will tail-off slightly over the next few days until the rain from the next weather cycle moves down into the aquifer. The level of the River Till has also continued to rise slowly but steadily steadily over the last week. The Environment Agency has maintained the groundwater Flood Alert for the village, but not increased it to a Flood Warning, even though the water level is a metre over the trigger level and 0.5 metres below the level which even it considers to be “abnormal”. The Flood Alert on the Wylye and its tributaries (including the River Till) disappeared after less than 24 hours and has not been reinstated since. The new-ish monitoring station in Shrewton shows that the River Till is above the maximum level of what the Environment Agency consider to be its normal range and is heading towards the greatest depth previously recorded (9th May 2023). Too much credence shouldn’t be put on this last bit of information, as there is little underpinning data to support it; that will improve over the coming years.
Just how unusual this winter has been so far is better illustrated by the next graph. This shows the water depth on each 17th December of the last decade:
Only the 17th of December 2019 comes close to the situation today. In the winter of 2019-2020, groundwater levels first rose above the “normal” level on Christmas Day and stayed high until the end of March 2020. The start of this winter seems to be very similar.
We may get a few showers and patchy rain over the course of today. Monday will start dry, but with an increasing chance of rain in the afternoon. This will build into heavy persistent rain overnight and into Tuesday morning. This will clear and Wednesday should be nice and dry, but with damp weather returning on Thursday. We may get a dryish Christmas period, but not a chance of snow this far south – sorry kids! More wet weather seems likely coming up to the New Year. As with most winters, January seems set to be wave after wave of wet weather moving in from the Atlantic, but with a chance of a colder spell of weather around the middle of January.
Contains public sector information licensed under the Open Government Licence v3.0.