João Grilo, who owns a farm near the site, was surveying the banks when that part of the Mondego's main channel burst at 5:45 pm. A Civil Protection source confirmed to Lusa that the dike broke in Casais, on the right bank of the Mondego, near the motorway bridge, at kilometre 191.

According to the agricultural entrepreneur, there is a risk of another breach on the right bank, near the Coimbra Equestrian Centre, further upstream.