1. Gilfillan Lake: Sustainable Lake Management Plan Meeting 1 April 22, 2009

2. Overview for Tonight Data presented to assist you in developing your vision for the lake Water balance for Gilfillan Lake  Water Balance: Sources and sinks for water in Gilfillan Lake  Ideas to control lake levels with group input Intro to Shallow Lakes Management  Definition of A Shallow Lake  Shallow Lake States: Clear vs. Turbid  Shallow Lake Management and Goals  Tools at our disposal with group input

3. Sample Visions: Lake level may vary seasonally or by precipitation received but generally remains at or around the established Normal Water Level. Gilfillan Lake has a healthy fish community, and anglers can catch and eat a variety of fish year round. Gilfillan Lake supports waterfowl and other upland and aquatic wildlife. Only non-motorized boats may be used on Gilfillan Lake. Gilfillan Lake is impaired by nuisance algae blooms no more than 10% of the season (April 1 – October 31). Submerged and emergent aquatic vegetation is limited to the near- shore areas. Gilfillan Lake is safe for swimming. The community is involved in planning for and monitoring Gilfillan Lake.

4. Water Balance LAKE OUTFLOW Sinks of Water  Evaporation off lake surface/ Evapotranspiration  Outlet  Groundwater Extraction by private wells in the area & leakage through lake bottom Sources of Water  Precipitation  Stormwater runoff from the tributary watershed  Groundwater Septic inputs

5. Precipitation: 33 inches average (22.8 to 45.7 inches)

6. Watershed Runoff: 17-35 inches average

7. Gilfillan Lake:

8. Precipitation and Lake Level; loosing ~12 inches

9. Increase Lake Levels Get more water to the lake  Increase drainage area (more stormwater)  Augmentation from another source 1,000,000 gal/yr w/o permit= <0.5 inches over lake surface DNR doesn’t believe lake level augmentation is not a legit use of groundwater Tie it to an impairment? Keep water from leaving  Prevent groundwater leaving  Modify outlet  Use less groundwater in the area

10. Shallow Lakes Definition Shallow Lake States: Clear vs. Turbid Management Tools Group input (later)

11. Shallow Lakes: Definition Definition >80% littoral or max depth <15 feet

12. Shallow Lake States: Clear

13. Shallow Lake States: Turbid

14. Shallow Lakes: Biology

15. Shallow Lakes: Management Biology & Hydrology  Control sources (nutrients)  Rough fish management  Plant management  Water level management

16. Sample Visions: Lake level may vary seasonally or by precipitation received but generally remains at or around the established Normal Water Level. Gilfillan Lake has a healthy fish community, and anglers can catch and eat a variety of fish year round. Gilfillan Lake supports waterfowl and other upland and aquatic wildlife. Only non-motorized boats may be used on Gilfillan Lake. Gilfillan Lake is impaired by nuisance algae blooms no more than 10% of the season (April 1 – October 31). Submerged and emergent aquatic vegetation is limited to the near- shore areas. Gilfillan Lake is safe for swimming. The community is involved in planning for and monitoring Gilfillan Lake.