Flooding may affect Primrose Close, The Meadows, Castle Lane, Mill Lane, Old Bury Road, Bridge Street, Riverside Walk, Canon’s Close, Coney Close and Coventry Way in Thetford, Teal Walk, High Street and Riverside Way in Brandon and Church Lane in Hockwold.
But they added: No further significant rainfall is expected over the next 48 hours, therefore we expect river levels to continue to slowly reduce.
An alert also remains in place at the River Nar at Narborough, Marham, Wormegay and Saddle Bow.
The Environment Agency said river levels had fallen at Marham, but remained high at Setchy Bridge river gauge.