John Slater, who was 63, was elected in 2009 as a Liberal in the riding of Boundary-Similkameen, but ended his career in provincial politics as an Independent after the Liberal party did not endorse his candidacy for the 2013 election.
The B.C. Liberal Party said then that personal issues were behind the decision not to support Slater's candidacy for re-election.
The former mayor of Osoyoos acknowledged some personal problems, but suggested in 2013 that he may have ruffled feathers with his candid opinions on Liberal issues.
Earlier, Slater said a combination of prescription medication, antihistamines and a glass of wine left him out of sorts in the legislature where he was seen swaying in the hallway.
Premier Christy Clark paid tribute to Slater, saying he dedicated 30 years of public service to his community.
"John lent his time to everything from coaching youth sports and volunteering with the chamber of commerce, to standing for public office — first as a councillor, then mayor, and finally as MLA," Clark said in a statement.
"But no matter what his official title was, John always thought of himself first and foremost as a farmer."
She said Slater laid the groundwork for modernizing the century-old legislation protecting B.C.'s fresh water and was proud of the new Water Sustainability Act.
Slater's hard work included a new high school in Oliver, B.C., and a new Horizon Health Centre in Osoyoos, Clark said.