Metropolitan Groundwater Model for Water-Supply Availability Analysis

1. Metropolitan Groundwater Model for Water-Supply Availability Analysis Technical Advisory Group Meeting June 19, 2008

2. Quick Review

3. Model Domain Anoka • Entire 7 county metro • Extend to edge of Mt. Simon – Hinckley Aquifer to NW • 4913 sq miles • Model cell size: 500m • 417,793 active cells Ramsey Washington Hennepin Carver Dakota Scott

4. West East Dakota Carver Washington Hennepin St. Peter Glacial Drift Prairie du Chien Jordan St. Lawrence Franconia Mt Simon-Hinckley Ironton-Galesville Eau Clair Model Layers • All major aquifers and aquitards included • Total of 9 Layers

5. Rivers and Streams • All rivers and streams represented with lake package

6. River Segments • Each river broken into segments (reaches) • Stage based on topography or gage data

7. Lakes • Stage from DNR or DEM • Deeper lakes allowed to be in deeper layer • Represented with River Package

8. Targets • 14,542 Head targets • SWL from CWI • 33 Baseflow targets • 55 Transmissivity targets • Pumping Tests • 378 Anisotropy targets • Penalty for Kz > Kx within a zone

9. Head Targets • 14,542 head targets • Static water levels from county well index • Cross-validated

10. Baseflow • 33 baseflow reaches

11. Transmissivity Targets

12. Temp, Julian Day Wind Daily Precipitation EVAPOTRANSPIRATION Topography(30-m Digital Elevation) Land Use (including imperviousness) SURFACE RUNOFF Soil Type (Hydrologic Classification) RECHARGE Surface Water Balance (SWB) Model for Recharge (Adapted from Dripps and Bradbury, 2007)

13. SWB Recharge Output • Mean recharge 1975-2003 • 30m grid

14. Recharge Model Grid • 500 m grid

15. Calibration Parameters • 756 hydraulic conductivity zones • 378 Kx=Ky • 378 Kz • 8 lake conductance zones • 33 river conductance reaches • Recharge remained fixed

16. Quaternary Zones • Zones roughly defined based on sand content • 65 zones

17. Quaternary Zones • Zones roughly defined based on sand content • 65 zones

18. Jordan Zones • 48 zones • Zones defined based on first bedrock unit and subdivided into additional zones

19. Calibration Results for Head Targets

20. Calibration Stats • Mean Head Residual = -1.65 m • Residual Standard Deviation = 5.18 m • Minimum Head Residual = -31.21 m • Maximum Head Residual = 33.08 m • Total range of observed values = 125.27 m • Percent of head residuals within 5% of range = 93.2%

21. Baseflow Residuals

22. Horizontal Hydraulic Conductivity

23. Vertical Hydraulic Conductivity

24. Using the model to address future water supply Example for the City of Ramsey

25. City of Ramsey

26. City of Ramsey (Runkel, 2006)

27. Projected Municipal Demands (Ramsey)

28. Regional Model • Run regional model with 2050 average day pumping • Extract TMR for more detailed analysis • Used constant head boundaries at edge of TMR

29. Municipal Supply Wells

30. Municipal Supply Wells • Well spacing about 1 mile

31. Grid Refinement • Refine grid in the Ramsey area

32. Ramsey Well 7 Pumping Test Observation Well

33. Drawdown (m) Time (days) Ramsey Well 7 Pumping Test Pumping Rate: 1000 gpm (constant)

34. 2030 Drawdown in Ironton - Galesville (Average Day) Contour Interval: 1 ft

35. 2030 Drawdown in Ironton - Galesville (2 Week Peak) Contour Interval: 2 ft

36. 2030 Drawdown in Layer 1 (Average Day) Contour Interval: 1 ft

37. 2030 Drawdown in Layer 1 (2 Week Peak) Contour Interval: 1 ft

38. 2050 Drawdown in Ironton - Galesville (Average Day) Contour Interval: 1 ft

39. 2050 Drawdown in Ironton – Galesville (2 Week Peak) Contour Interval: 2 ft

40. 2050 Drawdown in Layer 1 (Average Day) Contour Interval: 1 ft

41. 2050 Drawdown in Layer 1 (2 Week Peak) Contour Interval: 1 ft

42. Head Above Franconia (2050, 2 Week Peak)

43. Water Table Distance From Ground Surface

44. Wetlands in Ramsey

45. Additional Info

46. Layer 1 Residuals (Quaternary)

47. Layer 2 (St. Peter)

48. Layer 3 (Prairie Du Chien)

49. Layer 4 (Jordan)

50. Layer 5 (St. Lawrence)