Tadakuni was placed under house arrest and ordered to retire,then later transferred to the Yamagata Domain of Dewa Province, after Tadakiyo MIZUNO, his eldest son, was allowed to succeed the family reigns.
家督は長男・水野忠精に継ぐことを許された上で強制隠居・謹慎が命じられた上、まもなく出羽国山形藩に懲罰的転封を命じられた。