Diss is a market town and electoral ward in Norfolk, England close to the border with the neighbouring East Anglian county of Suffolk, with a population of 7,572. (2011)The town lies in the valley of the River Waveney, around a mere (lake) that covers 6 acres (2.4 ha). The mere is up to 18 feet (5.5 m) deep, although there is another 51 feet (16 m) of mud.