It follows release of a report in May last year that recommended expansions in 21 river valleys in four areas around Hamilton and the Niagara Region.
The province’s proposal adds areas around Kitchener-Waterloo and Guelph.
Waterloo Region Chairman Ken Seiling said the proposals are actually less protective of farmland and water resources than some existing policies in his region.
However, a veteran activist on the issue says including the Waterloo Region is a step forward.
The report issued in May made 87 recommendations, including allowing higher urban densities – an increase from the current level of 50 to 80 jobs per hectare.
The existing greenbelt is about 800,00 hectares around Toronto, Hamilton and into the Niagara Region.