Gadiano was also the former Mayor of Sablayan from 2010 to 2019.[2] He also served three full terms as vice mayor prior to becoming the chief executive of the town.[3] As presiding Officer of the Sangguniang Bayan of Sablayan, he was responsible for instating a 25-year moratorium on large scale mining.[3] Despite this the national government granted an exploration permit to a mining company, with Gadiano as mayor of Sablayan refusing to accept the firm's occupation fee. The firm filed a case in a local court in response to Gadiano's resistance.[4]
As Occidental Mindoro governor, Gadiano has reached out to the national government to intervene in the dispute between power distributor Occidental Mindoro Electric Cooperative Inc. (Omeco) and power supplier Occidental Mindoro Consolidated Power Corp. (OMCPC) to help resolve the electricity situation in the province.[6][7]