Katsumune was appointed to Fudai daimyo (hereditary vassals to the Tokugawa Family) from Tozama daimyo (non-hereditary one) in 1684 and this made his service in the Edo Castle extremely long, therefore, Katsuyoshi MIZUNOYA, his son, and Yoshitoshi TSURUMI, the chief retainer, took charge of the domain duties for a while.
1684年、外様大名から譜代大名に列せられたが、このために江戸城における勤務が極端に長くなったため、しばらく藩政は子の水谷勝美と家老の鶴見良俊が担当した。