Water Management of Turtle Lake Watershed Sept 29, 2007 by Don Dill

Presentation Outline  Watershed Characteristics  SWA –Sask Water Involvement with Water Involvement with Water Levels since 1984 Levels since 1984  Roles SWA Plays in Water Management in Watershed Management in Watershed  Questions

Watershed characteristics  Gross Drainage Area 649 km km 2  Effective Drainage Area Area 555 km km 2  Area of Turtle Lake 64 km 2 64 km 2  Net evaporation About 340 mm

Watershed Characteristics Inflow Volumes (1 dam = 1000m 3 or 220,000 gallons) Volumes (dam 3) Peaks (m 3 /sec) Volumes (dam 3) Peaks (m 3 /sec)  1: 2 18,  1:5 26,  1:10 33,  1:25 42,  1:50 49,  Annual net evaporation = 21,200 dam 3

Water Level Peaks  Water level peak this year m.  1:100 peak water level m. used in hydrology used in hydrology studies studies  The 1:00 level is being reviewed to determine if changes need to be made.

Historical Water Levels

Outlet of Turtle Lake April 1990

Silt from ditching carried out July 19, 1984

Obstruction placed July 19, 1984

Obstruction May 25, 1985

Obstruction in Channel May 28, 1985

Outlet July 16, 1985

Sask Water Timber Weir  Overflow elevation varied between m. and m. between 1970 and  Set weir at historical average level  Set at m.  Supposed to be temporary until consultation completed and new structure designed

Temporary Wood Structure Installed April 25, 1986

Temporary Wood Strucutre Installed April 25, 1986

Planning Study Initiated in 1986  Public Opinion Survey carried out in June of 1986  Public Meetings held in the summer of  Petitions circulated with hundreds signing to object to the elevation of the timber weir ( too low)  Lots of consultation but no consensus

Watershed Authority Water Management Roles  Regulate Water Use Example water lines into cabins Example water lines into cabins  Regulate Drainage Activity Example farm drainage or diversions for flood control.  Deal with Drainage Complaints Example – municipalities impounding water with road grades

Watershed Authority Water Management Roles  Deal with Water Management Inquiries Example municipalities seeking advice on proper placement of culvert Example municipalities seeking advice on proper placement of culvert  Review sub division applications and advise on Estimate Peak Water Levels (Vary between and m. for various locations around lake )  Review Forest Management Plans  Review projects going through the Environmental Assessment Process

Changing Watershed from Forest Harvesting  White blocks areas north and east of lake north and east of lake are harvested are harvested areas in 1990 areas in 1990

Watershed Authority Water Management Roles  Undertake water quality monitoring with Stewardship groups  Provide advice and assistance to protect riparian areas  Take a lead role in preparing Source Water Protection plans for the north Sask. Watershed including Turtle Lake

Main Role of SWA  We are working on behalf of you to protect surface and groundwater supplies and quality.  Your views and comments are essential for successful management of our water resources

Questions