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

2. 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

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

4. 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 18,700 5.6  1:5 26,800 9.0  1:10 33,000 12.0  1:25 42,000 15.5  1:50 49,000 20.0  Annual net evaporation = 21,200 dam 3

5. Water Level Peaks  Water level peak this year 655.24 m.  1:100 peak water level 655.16 m. used in hydrology used in hydrology studies studies  The 1:00 level is being reviewed to determine if changes need to be made.

6. Historical Water Levels

7. Outlet of Turtle Lake April 1990

8. Silt from ditching carried out July 19, 1984

9. Obstruction placed July 19, 1984

10. Obstruction May 25, 1985

11. Obstruction in Channel May 28, 1985

12. Outlet July 16, 1985

13. Sask Water Timber Weir  Overflow elevation varied between 654.62 m. and 654.93 m. between 1970 and 1984.  Set weir at historical average level  Set at 654.78 m.  Supposed to be temporary until consultation completed and new structure designed

14. Temporary Wood Structure Installed April 25, 1986

15. Temporary Wood Strucutre Installed April 25, 1986

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

17. 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

18. 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 656.65 and 655.7 m. for various locations around lake )  Review Forest Management Plans  Review projects going through the Environmental Assessment Process

19. 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

20. 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

21. 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

22. Questions