Persistent heavy rain caused problems across the entirety of Dumfries and Galloway on Friday December 30.
Water in the Nith reached its highest ever recorded level, affecting communities all along the river bank, including the village of Kirkton which ended up completely cut off by the water.
There were reports of traders on the Whitesands being told not to worry about their businesses flooding in early Friday afternoon, only for water to start running in a couple of hours later.
Explaining the process behind issuing flooding advice and projecting the risk, Vincent Fitzsimons, head of hydrology and flooding at SEPA, this week said: “Following forecast heavy rain, southern Scotland experienced a significant flood event on December 30.
“SEPA’s network of measurement gauges recorded intense rainfall over a few short hours on Friday morning, followed quickly by rapid rises in river levels. This led to the highest ever recorded river level at the Nith of 5.31m at the Whitesands Gauging Station.
“SEPA staff worked with Met Office colleagues to forecast the event in advance. We issued alerts and warnings on the basis of this forecast and then updated them depending on our monitoring of rainfall and river levels during the event.
“These alerts and warnings were sent directly to people who signed up to our Floodline service. We also communicated these through other channels, and were in close contact with emergency responders throughout the event.”
The first flood alert was raised on Thursday morning and that afternoon SEPA issued a localised flood warning for Whitesands.
On Friday morning the localised flood warning was updated to warn of property flooding adjacent to the river, then that afternoon a severe flood warning was issued – the highest level that SEPA issues and indicating potentially life-threatening risk from flooding and significant damage to properties. This was done in consultation with responders via Local Resilience Partnership meetings.
Vincent added: “We know that timely receipt of regional flood alerts and local flood warnings is important. We encourage people sign up to our free Floodline service and we work hard to provide as much notice of forecast flooding as we can, to help people take action.”
Meanwhile, responding to calls for river dredging, he pointed out it can also increase flood risk downstream and cause serious environmental damage.
Dumfries and Galloway Council’s website also warns of the pitfalls of dredging and says a modelling exercise found that lowering the river bed by 100mm was shown to reduce water levels by only 50mm during a flood, which they described as “an insignificant benefit”.
