NB’s watersheds at risk

Written by Megan de Graaf on April 16, 2008

Research from Quebec has shown that when more than 50% of a watershed is clearcut (or equivalent-clearcut) there is a moderate probability that peak flow will be severe enough to damage the river or stream channel and the habitat it provides. These effects are known to last for 35 years, because young forests do not effectively regulate water quality and flow. This effect is amplified by extreme rainstorm events, which have become 5 times more frequent during the last 10 years in New Brunswick thanks to climate change.

Using data provided by the Department of Natural Resources, CCNB undertook an analysis of all watersheds in the province to calculate the amount of Crown (public) forest within each watershed that is less than 35 years old. This analysis of Crown forest age in New Brunswick watersheds has shown 30 watersheds are at risk where young forests cover 40% or more of the drainage area. These “at risk” watersheds are located within five of the province’s thirteen principal catchment basins: Restigouche River, Chaleur Bay, Nepisguit River, Miramichi River and Saint John River.

The South Branch Nepisguit River, with 62% of the land base covered in Crown forest less than 35 years old, is the most critically affected watershed in the province. The extent of young forest in that watershed can be contrasted with the adjacent low risk Portage Brook Composite watershed, for example, which contains only 12.5% young Crown forests. CCNB analysis shows that the Nepisguit River and the headwaters of the Restigouche, Northwest Miramichi, Jemseg, and Canaan Rivers are themselves at-risk because of the large number of watersheds within each catchment basin that are at-risk.

Forest management practices do not prioritize protecting our freshwater resources in New Brunswick. Clearly, several watersheds in New Brunswick may soon be insufficiently forested to protect against unstable flows of water, especially as the climate continues to change. To protect rivers and lakes in New Brunswick there must first be an acknowledgement by New Brunswick legislators of the necessity of holistically protecting water quality and aquatic habitat, even if it impedes conventional economic endeavours.

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