“As go the headwaters, so goes the – creek – river – lake - watershed.”
For many years it was believed by forest managers that headwaters could be protected by the placement of a standard set-back “doughnut” (lakes) or linear reserve (creeks), where no logging or reduced intensity logging could occur – a “one size fits all” solution. This neither precluded access roads through the set-back nor the extraction of aggregate for haul-road building and/or maintenance.
More recently, it has become recognized by managers that since groundwater follows the nap of the earth, elevated areas adjacent to headwaters, as a result of glacial activity, may be supplying ground or surface “spring” water via lenses, which maintain headwater flow during part or all of the year. Many such scenarios have resulted historically in the formation of headwater lakes and creeks that support self-sustaining (lacustrine) brook trout (Salvelinus fontinalis) populations.
I hope to present a convincing case utilizing GIS and low-level aerial photography within the Algonquin Park Watershed of south-central Ontario, Canada, to illustrate that anything short of complete protection of all headwater catchment zones, be they urban or forested, is insufficient to ensure their viability for future generations.