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Audit and Evaluation Annual Report 2009–2010

Annex 1 - Network Configuration

Annex 1 - Network Configuration

History of Water Monitoring in Canada

To understand the current configuration of the hydrometric network in Canada, it is useful to review the history of the development of the network. A comprehensive history of the Water Survey of Canada was prepared by Halliday (2008) marking the one hundredth anniversary of the first parliamentary appropriation for stream gauging. This section of the report draws primarily from that history.

The federal government took a major role in the establishment of the hydrometric network for a number of reasons. The early water level observations in the Great Lakes-St. Lawrence system were related to navigation, a constitutional responsibility of the federal government and the Colonial Government prior to Confederation. The development of the hydrometric network in Alberta and Saskatchewan originated with the needs of irrigated agriculture, a shared constitutional responsibility. The hydrometric network in British Columbia started with monitoring in the federally administered Railway Belt, and expanded to the rest of the province. In response to interest in hydroelectric power development, Ontario started systematic stream gauging in 1912 and Quebec in 1913, and they assigned the task to the federal government in 1919 and 1922, respectively.

In the early days of the Survey, hydrometric work was carried out in two separate branches of the Interior Department: the Irrigation Branch in Alberta and Saskatchewan, and the Dominion Water Power Branch elsewhere. (The initial Railway Belt Survey in 1911 was carried out by the Railway Lands Division, Dominion Lands Branch.) The operation was identified by names such as the Manitoba Hydrographic Survey (the word “hydrographic” was replaced by “hydrometric” in 1917). On July 1, 1920, all hydrometric surveys conducted by the Department of the Interior were centralized in the Dominion Water Power Branch.

In 1908 there were 110 stations operated by various entities. By 1915, the hydrometric network had grown to more than 816 stations, and by 1922 there was an active hydrometric survey in every province. In 1929 the network reached 1024 stations. The Great Depression then intruded on the hydrometric program. The economic conditions and changed social priorities led to severe cutbacks in federal government programs. (The transfer of the responsibility for natural resources administration to the three prairie provinces in 1930, while welcome at the time, was a federal cost-saving measure.) The Minister of the Interior advised the provinces on March 31, 1932, that the agreements on hydrometric surveys would be terminated on March 31, 1933. The measurements required by the Boundary Waters Treaty continued as a federal expense. Some other work continued to be carried out under letter agreements with some provinces. The result was a network decline to 708 stations. All hydrometric surveys were discontinued in Prince Edward Island; they were not resumed until 1961. It would take until the 1940s before the hydrometric network reached the same level of development as it had in the 1920s. The network reductions in the 1930s had other consequences. In western Canada, the 1930s included several drought years. The entire decade is often described as a drought. The hydrometric network reductions therefore coincided with hydrologically important conditions. The loss of data during this period continues to haunt Canadian hydrological understanding.

The post-war boom of the 1950s resulted in increased government spending. The 1950s was a time of “nation building,” with engineering projects like the construction of the St. Lawrence Seaway. The hydrometric network was expanded under ad hoc arrangements with the provinces. By the end of the 1950s the network consisted of 1582 stations, a 50 percent increase from 1945.

The United Nations Educational, Scientific and Cultural Organization (UNESCO) International Hydrological Decade, 1965–1974, led to an international effort to increase global understanding of hydrological processes and provided an impetus to improve water monitoring. By the end of the decade, the hydrometric network in Canada had grown to more than 3000 stations.

Network expansion continued until the mid-1980s, then remained stable at about 3500 stations until the early 1990s. The decline beginning in the 1990s was, in part, a consequence of constrained resources at the federal and provincial level, as governments came to grips with major budget deficits. It was also the result of decisions made within Environment Canada that specifically targeted spending on water programs, including monitoring. After a precipitous drop in 2002, the largest numerical network decline in the history of Canadian stream gauging, the hydrometric network stabilized at about 60 percent of its size in the 1980s. The drop in network size is made up almost entirely of decreases in the number of federal and federal-provincial stations. In 1975, the first year of the Agreements on Hydrometric Monitoring, the federal government funded 60 percent of the cost of the network; the percentage is now less than 40 percent.

Current Network

Most provinces and territories in Canada have operating Agreements on Hydrometric Monitoring with the federal government for operation of their hydrometric networks. The Water Survey of Canada operates approximately 2100 hydrometric sites within the federal-provincial/territorial Agreements on Hydrometric Monitoring framework. And additional 800 or so stations are operated by the provinces, territories and “contributors” under the Agreements on Hydrometric Monitoring, for a current total of 2931.

Most stations in the National Hydrometric Program are in the higher populated areas in southern Canada. The history of network development shows that the network has evolved primarily in response to water management needs rather than scientific requirements.

The Reference Hydrometric Basin Network (RHBN) is an evolving sub-network of about 230 stations in the overall national hydrometric network, which complements Canada’s Reference Climate Station network of 300 long-term climate observing stations identified for use in addressing climate change and variability (Environment Canada 1996) in, predominantly, temperature and precipitation. These networks help to meet Canada-wide and regional needs. They also represent a major step forward in addressing the need for Canadian data in support of hemispheric and global scale scientific studies of climate change.

The National Hydrometric Program has a well-established partnership system. There are agreements between the federal government and most provinces/territories for the operation of the federal and provincial networks, and the data for all stations are reported under the National Hydrometric Program. Partnerships under the program have also been established between provinces and organizations such as hydropower utilities and municipalities.

The hydrometric stations funded by the federal government have not increased in number in recent years. It is recognized that the RHBN needs to be reviewed and stations added as record lengths increase for stations that are currently not in the RHBN. If all ecoregions in Canada are to be included in the RHBN, a significant number of additional stations would be required. The additional stations could also serve other purposes.

The partnership programs have been successful at establishing new stations and stabilizing funding for parts of the network. However, there is a downside to the partnership system, as it introduces a bias in the network toward stations required for water management and away from regional stations in unregulated pristine watersheds, which could be used for climate change detection and other scientific and regional hydrology applications. With the partial exception of the RHBN, the hydrometric network in Canada has evolved without priority given to stations with long-term records in pristine areas that would be of scientific value, particularly for detecting climate change. Factors mitigating against these types of stations include the following:

  • The partnership programs used to solidify the network tend to focus on stations for water management.
  • Monitoring stations are often implemented for scientific purposes as part of a special program. However, the stations are often discontinued after a few years because the funding for the special program is terminated.
  • It is more costly to maintain stations in remote, pristine areas, so network managers are less likely to install stations in those areas when they have limited budgets.
  • The variability of network budget allocations in most jurisdictions results in stations being closed for a period of years and then reopened later, which creates a gap in the long term record.

Proposed Network Improvements To Date

For the past 20 years there has been interest in Canada to improve water monitoring networks, particularly to detect climate change. A workshop was held in 1992 by the National Hydrology Research Institute, called Using Hydrometric Data to Detect and Monitor Climatic Change. The primary objective of the workshop was to provide directions to Environment Canada toward evolving a network that could be used to detect and monitor climate change. The recommendations on monitoring were as follows:

A greater effort is warranted to evaluate the existing network for its potential use in addressing the climatic change issue. Criteria should be refined for a national hydrometric reference network. Long-term stations need to be maintained and coverage of the North and small basins should be improved.

Although the hydrometric network in Canada declined in the 1990s, stations that formed the RHBN were designated following the workshop, as a result of that initiative.

In 2001, Environment Canada hosted a National Science Workshop, Trends in Canadian Hydrological Time Series. It was one of the final deliverables of an 18-month Climate Change Action Fund project entitled Monitoring the Impacts of Climate Change on Canada’s Water Resources, which involved several experts from the Meteorological Service of Canada, the National Water Research Institute, three Canadian universities and the private sector.

The workshop participants concluded that there are general trends toward decreasing flows and earlier spring runoff in southern Canada, which is consistent with precipitation and temperature trends. Specific results varied, however, due to different statistical methods and assumptions, and due to data limitations resulting from the poor spatial distribution and short record length of much of the hydrometric network, especially in central and northern Canada.

The participants recommended improved long-term integrated climate and hydrometric monitoring, better linkages with scientists engaged in climate modelling and adaptation strategies, and the development of a long-term strategy.

In 2004, in response to Canada-wide concerns about the impacts of climate change and about other water related issues, a national science assessment was published by Environment Canada, entitled Threats to Water Availability in Canada. The document was intended to serve water science decision makers, resources managers and the research community, as an important reference for developing future research directions and priorities, and sound management policies and practices. The report concluded that there are deficiencies in the design, operation and coordination of Canada’s surface water, groundwater and climate monitoring networks. Expansion of baseline monitoring of key components of the hydrologic cycle was recommended.

The Threats to Water Availability in Canada chapter Climate Variability and Change, Rivers and Streams (Whitfield et al. 2004) noted that the current Canadian approach of a data collection process driven by immediate needs is unlikely to result in an adequate network for providing basic data for evaluating impacts of climate variability and change on water resources. A thorough review and design of our observing networks was recommended, together with enhancing data collection in northern Canada where the changes in local climates are predicted to be larger than in the south. With this focus, it was noted that we are more likely to be able to verify that change is occurring as predicted. As far as can be ascertained, there has been negligible progress on implementation of the recommendations of the national science assessment Threats to Water Availability in Canada.

To overcome the current network deficiencies, the Hydrometric Monitoring Business Case (Environment Canada 2006) proposed an enhanced monitoring network for Canada. The document provided details on the network improvements that would be required to meet the needs of clients. Figure 1 integrates Environment Canada’s two key frameworks, the National Drainage Area Framework (970 sub-sub drainage areas) and the National Terrestrial Ecological Framework (1020 eco districts), to identify network deficiencies. In order to have sufficient information, there needs to be at least one active hydrometric station measuring natural flow in each corresponding eco district within a sub-sub drainage area. This strategy ensures that there will be sufficient information to understand the hydrological processes and the interrelationships with the landscape. This information is essential for research and for enhancing predictive capabilities and data transfer.

As the map shows, areas of sufficiency are concentrated in the southern, more populated regions of the country. Network sufficiency declines to the north and northeast, with great extents of northern Canada having no coverage at all.

Figure 1: Deficiencies in National Hydrometric Network

Figure 1: Deficiencies in National Hydrometric Network

Source: Hydrometric Monitoring Business Case (Environment Canada 2006)

Based on the above strategy, Canada would need an additional 928 new hydrometric stations to optimize the proposed enhanced network and to more adequately characterize Canada’s diverse hydrology.

Hamilton and Whitfield (2008) addressed the extent to which water monitoring networks meet science needs, in a commentary entitled “Coupling Science and Monitoring to Meet Future Information Needs” in the Canadian Water Resources Journal. They comment as follows:

Complex, interactive, environmental issues are a cause for concern about the future of our environment and our economy. Our existing scientific understanding of these issues is insufficient to even fully comprehend, let alone effectively manage, the risks of decisions that are being made in the face of unknown uncertainty. Developing improved process understanding, change-detection and prediction capabilities to respond to this challenge will require a fresh approach to how we connect science and monitoring. Addressing this challenge requires developing a strategy in which monitoring is considered as an integral part of a science-based solution complete with clearly stated questions, methodologies and analytical frameworks. Such a strategy must be robust to changing opportunities and challenges while preserving core values of the existing data legacy.

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