WATER

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WATER QUANTITY

Indicators

  • Water Levels*
  • Stream Flows*
  • Ice Phenology (freeze-up and break-up)*
* Trend graphs are available for indicators highlighed in orange.

Trend Graphs (NEW)

Indicators

Trend Graphs
Water Levels
Stream Flows
Ice Phenology
(freeze-up and break-up)

Current Knowledge

Baseline water quantities (natural amounts) of water in the NWT depend on the physical properties of the land, such as rock and soil, vegetation, slope and permafrost; and latitude. There are three main regions, and two lakes, which are studied: the Northern Cordillera (mountains), Interior Plains, the Precambrian Shield, and Great Bear and Great Slave lakes.

In the Northern Cordillera, streams flow fast, and lakes and wetlands are few. Stream flow peaks during spring snowmelt and after summer rainstorms. In winter, stream flows can fall to very low or zero values. The Interior Plains and Precambrian Shield regions have many lakes and wetlands, which are able to store and release water slowly during the summer months. Peak flow in these regions occurs only in the spring when snow is melting. Great Bear and Great Slave Lakes, because of their size, are able to keep the amount of water flowing out of them relatively constant throughout the year.

There is a network of 75 stations for water quantity monitoring, 22 of which are studied for part of the year only. There is historic information from 50 other sites that are no longer monitored Data from these stations shows that the amount of water in streams and lakes varies quite a bit from year to year, and from season to season. No trends indicating changes in stream flows have been noticed in the NWT except in the Slave River, Great Slave Lake and the Mackenzie River, which were affected by the Bennett Dam. In order to predict natural variations in river flow, at least 30 years of information are needed, and these records seldom exist.

Changes in timing of freeze-up and break-up, and river travel patterns and routes are unknown. Some information from trading posts and community residents may help, but this information must be interpreted carefully.

Current Monitoring

  • Northwest Territories water quantity monitoring program includes basin flow, quantity, ice phenology and modeling component of 87 stations operated by the Water Survey of Canada
  • Ongoing abandoned mines evaporation/water balance studies for water management purposes- INAC
  • Global Energy and Water Cycle Experiment (GEWEX) – models water and energy cycles on the Mackenzie River
  • Improved Processes and Parameterisation for Prediction in Cold Regions (IP3)- Canadian Foundation for Climate and Atmospheric Sciences(CFCAS) – operates from University of Saskatchewan
  • Lower Carp Lake and Snare River – water balance studies as part of GEWEX
  • Forest Fire Effects at Tibbit Lake –INAC
  • Coppermine Cumulative Effects Monitoring Program – water quality and quantity, INAC, Wildfred Laurier University
  • Dendrochronology (tree ring width) for stream flow and precipitation for northern watersheds- INAC, EC, University of Regina, Carleton University
  • Northern Rivers Ecosystem Initiative (NREI) – multiple partners working on pollution prevention, ecological management, contaminants, nutrients, long-range transport, and research in northern rivers (EC, GNWT, Government of Alberta)

Gaps and Recommendations

In order to have data for comparison with future conditions, information is needed for East Bank tributaries of the Mackenzie River (along proposed gas pipeline route), the Liard basin, the Lockhart and Coppermine basins (related to diamond mine developments) and areas with no development. Specific areas with oil and gas or mineral development need to be monitored.

Long-term information, and links with weather and sediment information need to be improved to help to detect trends. Create a sub group to coordinate a multi-research study to better understand water systems and use this study to build future models. Reopen recently closed monitoring sites and install new ones (along the east bank and proposed pipeline route). Tree ring studies need to continue and traditional knowledge of freeze-up and break-up dates and changes in travel patterns and routes needs to be documented.

Source: A Preliminary State of Knowledge of Valued Components for the NWT Cumulative Impact Monitoring Program (NWT CIMP) and Audit - Final Draft. February 2002; updated February 2005 and June 2007.

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