I am grateful to Alan Summerfield (see comment above) for correcting my erroneous understanding of the geography of local government along the Norfolk/Suffolk border. Passing from Lowestoft to Norwich along the A146 via Beccles had given me the impression that Waveney District lay between Norwich and the coast. The name of the district is taken from the river that divides the two counties.
The map below may help clear up any further confusion; it can be seen that the ward in question (Ward 12 Worlingham) lies across this river from Norfolk. I apologise for any confusion—and more especially any insult for the people of Norfolk and Suffolk are both proud and distinct and don’t take kindly to being confused.
Especially by a foreigner.