Having a shoreline zone well vegetated with native plants, shrubs and trees is a major goal in preserving water quality. A natural shoreline soaks up and filters runoff that carries nutrients, and prevents soil erosion. It also discourages nuisance geese and accumulation of goose waste, which contains e. coli and nutrients.

The Rideau Valley Conservation Authority recommends a 30-metre vegetative buffer for at least 75% of shoreline. As shown by this map (using Google satellite), natural vegetation cover for Lac Mahon is generally good, with pockets of ornamental cover. The easiest way to regenerate a shoreline is to stop mowing some lawn and let nature take its course, while still viewing the lake and having a dock area.

See attachments and Shorelines.