The Middle High German word 'riet' means, 'reed', a name for a plant. According to
http://www.ancestry.com/name-origin?surname=Ried, Ried is a topographic name from Middle High German riet 'damp, mossy area', ‘wet land’. This is where reeds grow, in wet lands.
Rietz can also be a personal name. A variant of Reitz, it can derive from Richard or Heinrich.
This message was edited 4/2/2013, 5:05 PM