NWT RESEARCH DATABASE

Regions: North Slave Region, South Slave Region

Tags: physical sciences, mining, climatology, hydrology, limnology, environmental baseline

Objective(s): To collect additional data that describes the existing surface water and climate conditions at the Thor Lake Property.

Project Description: The goal of the 2011 Surface Water Hydrology & Climate program at Thor Lake is to collect additional data that describes the existing surface water and climate conditions at the Thor Lake Property. This information is required for continued baseline monitoring, environmental assessments and water management plans for the area. Data obtained will help determine a quantitative description of the annual temporal and spatial distribution of stream flow conditions, precipitation, runoff processes, and lake levels at Thor Lake and its vicinity. The 2011 Surface Water Hydrology & Climate program at Thor Lake will re-establish the hydrometric monitoring network at the Thor Lake Property at the following locations: - Thor Lake - Thor Lake outlet - Fred Lake outlet - Cressy Lake - Long Lake - Beaver dam channel at Thor Lake (connection to Long Lake) - Murky Lake outlet Climate data will continue to be downloaded from the on-site climate station. Basic station maintenance will also be completed. Thor Lake hydrology data are collected at a series of water level and flow gauging sites located in the vicinity. Specifically, lake level monitoring is being conducted on Thor Lake and Long Lake. Stream flow and water levels are being monitored at the outlet of Thor Lake, the outlet of Fred Lake, the outlet of Long Lake, and at inflow sites to Thor Lake and Long Lake. Stream flow gauging will be completed at several streams connected to Thor and Long Lakes that have marginal autumn flows but expected high spring and summer flows. Water levels are monitored at each location using a HOBO pressure transducer that has been secured to the lake/stream bed. These devices are small, self-contained, non-obtrusive data loggers that are benign to the environment. Flow measurements at channels entering or leaving Thor and Long Lakes are derived by standard area-velocity, or volume measurements using a Swoffer flow meter and standard stream gauging techniques. These techniques have no impact on the water environment. Stantec will also train field assistants and/or Avalon staff, or other personnel designated by Avalon, in the installation and removal of the equipment, manual measurement techniques and data retrieval. Three site visits are proposed by the Stantec hydrologist: one during freshet to record flows during high flow conditions and install hydrometric equipment; one during mid-summer to obtain collect additional stream flow measurements; and, one in October to conduct further measurements and remove continuous monitoring equipment. Local field assistants will be hired to participate in the baseline field studies throughout 2011. Information including data and analysis on surface water hydrology in and around Thor Lake will be available to locals and communities for review. The information may provide locals with a more thorough scientific overview of the local surface water hydrology which can be used for various purposes (e.g., land use planning, economic development). Results of Stantec's 2008-2010 baseline studies at Thor Lake were communicated to members of affected communities in a baseline research update session in early 2011. Results from De'on Cho Stantec's 2011 baseline program will be provided to affected communities through Avalon as it proceeds through the regulatory, environmental assessment, and licensing processes. The fieldwork for this study will be conducted from July 15, 2011 to October 9, 2011.