ARCHIVED - Water Issues and Forests

Information Archived on the Web

Information identified as archived on the Web is for reference, research or recordkeeping purposes. It has not been altered or updated after the date of archiving. Web pages that are archived on the Web are not subject to the Government of Canada Web Standards. As per the Communications Policy of the Government of Canada, you can request alternate formats. Please "contact us" to request a format other than those available.

Freshwater: The Role and Contribution of Natural Resources Canada

There are approximately 418 million ha of forests in Canada, accounting for about 10 percent of the world's forests. Our forests contribute $34 billion to Canada's GDP and provide 376,000 direct jobs for Canadians. Canada is the world's largest exporter of forest products ($40 billion in 2003). Canada's forests are not only vital to our economy, but also to our nation's water supply. Forests are an integral part of the hydrological cycle; they recycle water to the atmosphere, which decreases water transport into ground and surface water. In addition, they filter air and water, moderate climate, provide habitat for wildlife, stabilize soil, and form a dominant feature of Canada's economy, culture, traditions and history.

Forests play a key role in moderating climate, regulating water systems, preventing erosion, alleviating air pollution and providing wildlife habitat.

Forest hydrology research[40]

Forest hydrology research in Canada was strongly supported by government in the late 1960s and early 1970s, a period known as the International Hydrological Decade. Gauges were set up and monitored in many watersheds, and a variety of studies examined the most immediate impacts of clear-cut harvesting practices on stream flow and erosion. The results of these studies were used in developing current forest management practices, which protect Canada's soils and freshwater resources. Although most harvesting operations still involve a one-pass removal system (clear-cutting), significantly smaller cut-blocks, protection of residual stands and gradual removal approaches, including selection cutting, shelterwood felling, and seed tree method, are increasingly used in Canada. The overall size of clear-cuts generally has been reduced, and the number of unharvested strips (leave strips) within cutblocks has increased.

Timber harvesting impacts on watersheds

A number of major urban centres derive all or some of their water supplies from forested watersheds. Because of these attributes, forested watersheds provide a range of important services to humans including provision of clean stream water and support of healthy aquatic ecosystems.[41] Research has demonstrated that the most significant impacts to forested watersheds following timber harvest are changes in water table levels, stream flow, water quality, erosion, and sedimentation. It is likely that similar changes occur after fire. Notably, watershed impacts differ between forestry practices and other land uses, including agriculture and mining.[42] As a general rule, harvesting impacts on streamflow regime and water quality are usually short-lived and less severe than those brought about by land-use changes, provided that forest soils are protected and vegetation recovery is rapid.[43]

The increase of sediment in water streams is linked to the building and use of forestry roads, and to direct disturbances of the stream bank by machinery.[44] Changes in forestry practices have been implemented across Canada to minimize these impacts. When regulations are respected, inputs of sediments into streams because of forest operations are short-lived and often small.[45]

Forest products manufacturing

There are about 155 pulp and paper companies in Canada, with over 500 more in related industries such as converted paper products, asphalt roofing paper, paper box, and bag industries. In 2002, shipments of pulp and paper totalled 30.5 million tonnes, for a value of approximately $26 billion. In 2001, Canada was the world's leading newsprint producer, with approximately 92 percent of newsprint production destined for export markets. The majority of the pulp and paper producers are world-scale operations located in remote communities close to the forest resource. The pulp and paper industry throughout Canada, particularly in the west, fulfills most of its fibre needs from chips produced in sawmills as a by-product of lumber making.[46] Although the pulp and paper sector has significantly reduced bark and wood waste production through process recycling, the management of water and wastewater residuals continues to be a major issue at most mills.[47]

Water use and wastewater in mills

Pulp and paper mills are big users of water. There are four essential functions of water in pulp and paper mills:

  • Process chemicals (e.g., adding water to sodium chlorate),
  • Conveying/controlling material through manufacturing unit processes,
  • Separating and purging contaminants from the product, and
  • Cooling: a significant water activity in mills to remove heat from different plant processes.

The pulp and paper industry, because of its diverse nature, can release a wide range of compounds into the aquatic environment. Research done on pulp and paper effluents has implicated fibre and suspended solids, colour and turbidity, and organic and nutrient enrichment loads as the three conventional pollutant factors with adverse environmental impacts.[48] The pulp and paper industry is also the third largest industrial polluter to air, water, and land in both Canada and the United States, and releases well over a hundred million kg of toxic pollution each year.[49] Over the last ten years the pulp and paper industry worked closely with the federal government, environmental non-governmental organizations, the provinces and other key stakeholders to ensure compliance with regulations under the Canadian Environmental Protection Act and the Fisheries Act.

The Canadian pulp and paper industry has invested billions of dollars towards research and technology aimed at reducing its emissions and improving the quality of their effluent. These investments in processes and technological changes have allowed the industry to achieve the following results:

  • reduced releases into water of chlorinated dioxins and furans by 99%;
  • decreased its carbon dioxide emissions (CO2), a key green-house gas, by 26% from 1990 levels;
  • reduced the use of products containing the toxic substance nonylphenol and its ethoxylates (NPE) by 99.8%; and
  • led to a 94% reduction in Biochemical Oxygen Demand (BOD) discharges and a 70% decrease in discharges of total suspended solids (TSS).[50]

Although mills have been successful in dramatically reducing the toxicity of their effluents, environmental effects monitoring data show that impacts continue in the aquatic environment.[51]

Water-Related Canadian Forest Service Activities

NRCan's Canadian Forest Service (CFS) has long recognized the need to better understand the linkages between forests, forestry practices and freshwater quantity and quality. NRCan science and policy activities regarding sustainable forestry and water-resource management cover a wide range of issues including: natural and forest management disturbances (including forestry practices) on water quality, quantity and forest hydrologic systems; innovative water resource conservation activities; best practices and knowledge transfer to policy making; and understanding how changes in climate affect the relationship between water and forestry practices.

Effects of forest practices on water quantity and quality

Timber harvesting has either positive or negative impacts on surface and ground water depending on the nature of the site and disturbance. To further understand the effects of human activities and other disturbances on forests and the environment, CFS conducts research on water and air quality, in collaboration with colleges and universities, other federal and provincial agencies, and private industries. This type of research provides a basis for the improvement of the harvesting regulations implemented by the provinces. These regulations minimize the negative impacts of harvesting by requiring, for example, stream-side buffer strips, road-building methods that control the discharge of surface water, and improved design of culverts and bridges.

Effects of pollution on watersheds

While some environmental concerns related to the forestry sector have been successfully addressed, there remains a need to better understand the role of forests in the global water cycle, and the cumulative environmental impacts of anthropogenic pollutants, sulfates, and nitrates on forests (Fig. 3-5). To address some of these concerns, CFS, in collaboration with partners, is monitoring water quality at a study site near Sault Ste. Marie, Ontario. The Turkey Lakes Watershed Study, is a multi-agency endeavour initiated in 1979 to evaluate the effects of human disturbance on Canadian Shield ecosystems. Participants in the study include both the federal and provincial governments and several universities. Originally focussing on the effects of acid rain alone, the study has evolved to include research on the effects of other pollutants and ecological disturbances such as forest harvesting and climate change.

Effects of pesticides on water quality

As part of its forest protection program, CFS investigates the fate and persistence of forest pesticides in water bottom sediments and aquatic systems, including fish, amphibians, aquatic insects, zooplankton, phytoplankton and microbial communities. Studies not only measure individual, population, and community-level effects, but include biotic interaction and ecosystem processes, and try to comprehend multiple stressor effects.

Effects of forest product manufacturing

NRCan supports research in the area of forest products manufacturing through institutes such as the Pulp and Paper Research Institute of Canada (Paprican). Paprican is a market-driven, applied research and technology institute whose mission is to enhance the technical competitiveness of the pulp and paper industries. From forest product research to technology dissemination, Paprican is integral to minimizing the pulp and paper industry's negative impacts on the environment. The three major environmental issues regarding the discharge of pulp and paper mill effluents are regulatory toxicity compliance, potential effects on fish reproduction, and fulfilling the regulatory environmental effects monitoring program correctly.[52]


40 Excerpt from: Thormann, M.N., P.Y . Bernier, N.W. Foster, D.W. Schindler, and F.D. Beall, "Land use practices and changes - forestry," pp. 57-66 in Environment Canada, Threats to Fresh-water Availability in Canada (Ottawa: Natural Resources Canada and Environment Canada, 2004), p. 57. Back to text.

41 Ibid, excerpt from p. 57. Back to text.

42 Ibid, excerpt from p. 58. Back to text.

43 Ibid, excerpt from p. 62. Back to text.

44 Mattice, C.R., Forest road erosion in northern Ontario: a preliminary analysis (Sault Ste. Marie, Ont.: Canadian Forest Service, Great Lakes Forestry Research Centre, Inf. Rep. O-X-254, 1977). Back to text.

45 Plamondon, A.P., "Augmentation de la concentration des sédiments en suspension suite a l'exploitation forestière et durée de l'effet." Can. J. For. Res. 13: 883-892, 1982. Back to text.

46 Information from NRCan's Canadian Forest Service web site: Back to text.

47 PAPRICAN, Back to text.

48 Owens, J.W., "The hazard assessment of pulp and paper effluents in the aquatic environment: A review," Environ. Toxicol. Chem. (10: 1511-1540, 1991). Back to text.

49 Environment Canada, National Assessment of Pulp and Paper Environmental Effects Monitoring Data: A Report Synopsis (NWRI Scientific Assessment Report Series, ISSN 1499-5905; no. 2, 2003). p. 36. Back to text.

50 Excerpt from Environment Canada news release: Environmental Regulation and Voluntary Actions Lead To Dramatic Reductions Of Air and Water Pollution From Pulp and Paper Industry (Ottawa: June 6, 2003). Available online at: Back to text.

51 Environment Canada, National Assessment of Pulp and Paper Environmental Effects Monitoring Data: A Report Synopsis (NWRI Scientific Assessment Report Series, ISSN 1499-5905; no. 2, 2003). p. 36. Back to text.

52 PAPRICAN, Back to text.

PreviousTable of contentNext