ROCHESTER — Planned changes for Silver Lake are being supported by Rochester’s Heritage Preservation, three years after much of the surrounding park was deemed a city landmark. The commission offered unanimous support for proposed changes that stem from plans to dredge the lake later this year. The proposed park changes required a commission review, due to the landmark status of the site. Molly Patterson-Lundgren, the city’s heritage preservation and urban design coordinator, said Tuesday’s review was intended to determine whether the proposed changes would significantly alter the historic nature of the park. Friends of Silver Lake member Dave Morrill, whose home sits on the north side of the proposed changes, a said he and others in the group disagree, saying the changes will alter the lake view from North Broadway Avenue.