Flooding on the Trent can also be caused by the effects of storm surges independently of fluvial flows, a series of which occurred during October and November 1954, resulting in the worse tidal flooding experienced along the lower reaches. These floods revealed the need for a tidal protection scheme, which would cope with the flows experienced in 1947 and the tidal levels from 1954, and subsequently the floodbanks and defences along the lower river were improved to this standard with the works being completed in 1965. In December 2013, the largest storm surge since the 1950s occurred on the Trent, when a high spring tide combined with strong winds and a low pressure weather system, produced elevated tidal river levels in the lower reaches. The resulting surge overtopped the flood defences in the area near Keadby and Burringham, flooding 50 properties.