Easter Lake / Yeader Creek Informational Meeting July 12, 2010

1. Easter Lake / Yeader CreekInformational MeetingJuly 12, 2010

2. Easter is a valuable lake

3. Outline • Easter Lake – Current Conditions • Diagnostic Study • Conditions from routine monitoring • Diagnostic monitoring plan • Project Goal – Restoration Feasibility Study • Identify locally perceived problems and restoration goals

4. Easter Lake

5. Easter Lake and Watershed One of Iowa’s most urban lakes

6. Easter Lake Physical Conditions

7. Easter Lake: What do we know from monitoring data? Chemical Profiles

8. Phosphorus • Long-term summer average for Iowa Lakes: 108 ppb • Surveys show “Swimmable”: less than 85 ppb • Easter Lake long-term summer average 68 ppb

9. Suspended Solids Long-term average for all Iowa Lakes: 22 ppm “Swimmable”: less than 15 ppm Easter Lake: long-term summer average 13 ppm

10. Chlorophyll-a Long-term average for all Iowa Lakes: 52 ppb “Swimmable lakes”: less than 20 ppb Easter Lake long-term summer average: 37 ppb

11. Secchi Depth Transparency Long-term average for all Iowa Lakes: 3.9’ (1.2 m) “Swimmable”: more than 3-4.5’ (1-1.5m) Easter Lake long-term summer averages: 2’ 7” (0.8 m)

12. Principal objective is to establish a water, nutrient, and material budget • Inputs • Tributaries • Storm drains • Precipitation • Outputs • Outfall • Evaporative loss (water not nutrients

13. Diagnostic StudyLake Water Quality Monitoring and Assessment • What types of things are we finding out? • “Storage” term in budget mass-balance • Water column profile data Temperature, Dissolved Oxygen, pH, Conductivity, Turbidity • Nutrients Phosphorus, Nitrogen • Transparency Secchi disk, Particulates • Lake productivity and condition Chlorophyll a, TrophicState

14. Diagnostic StudyWatershed Monitoring and Assessment • Hydrologic relationship of upstream and downstream waters • Tributary analyses YSI data, discharge, nutrients, bacteria • Real-time water level recording • Precipitation • Land use and land management alternatives (GIS) • Nutrient and sediment loading

15. Tributary sampling sites (real-time flow monitors)

16. Tributary analyses

17. In-lake sampling sites

18. In-lake analyses

19. Storm drains

20. Easter Lake storm drain sites

21. Diagnostic StudyLake Habitat and Biological Monitoring and Assessment • Littoral zone habitat evaluation • Sub littoral benthic macro-invertebrates • Fisheries community IDNR data on abundance, age, and growth • Fish-flesh analyses Herbicides, Insecticides, PCB’s, Mercury • Plankton • Bacteria and Microcystin

22. Diagnostic StudyLake Mapping and Sediment Monitoring and Assessment • Bathymetric mapping (sedimentation map) • Comparison of “as built” with current bathymetery • Sediment analyses • Insecticides, Herbicides, Heavy Metals

23. Diagnostic StudyOther Information • Population assessment and history of lake use • Public access and comparison of lake use among other Iowa lakes • Economic cost vs. benefit analysis • Impact assessment of degradation and restoration • Point-source pollution inventory

24. Restoration Feasibility Study • Past and current report summary • Lake restoration alternatives report • Impacts of lake degradation • Economic Cost / Benefit Analysis • Anticipated changes to aquatic biota • Monitoring program design • Assistance in public hearing process

25. Example: phosphorus budget of Black Hawk LakeHigh nutrient concentrations derive 70-90% from activities high in the watershed but direct input around the lake shores is also detrimental

26. Preliminary GIS (1” event) suggests lots of hot-spots

27. What’s left to do • Sampling finished last fall • Calculate budgets based on hydrology and nutrient concentrations • Complete GIS assessments • Examine lake sediment deposition • Determine restoration target for acceptable water quality • Propose feasible options

28. Iowa State UniversityEEOB Department • Website: http://limnology.eeob.iastate.edu • E-mail: “John Downing”downing@iastate.edu • Phone the lab: 515-294-6363 • Fax the lab: 515-294-1337