The swearing in ceremony took place at the county headquarters and was conducted by Nyeri High Court judge Jarius Ngaah.
Wamathai vowed to continue with his predecessor’s impeccable development record as he termed Gachagua’s demise as great loss to the county and nation in general.
Present at the event was Council of Governors chairman Peter Munya as well as the late governor’s family and count staff.
News of the governor’s death broke on Friday. Gachagua’s body will be flown back to the country on Thursday morning.
Wamathai said that Nyeri has lost a credible and legendary leader who will always be remembered for his development agenda.
Gachagua passed away while admitted to a hospital in London after a lengthy battle with pancreatic cancer.