1. Groundwater P = Q + ET + G +  S

2. Floridan Aquifer Extent

3. Geologic Profiles (Stratigraphy)

4. Confinement

5. Groundwater and Wetlands

6. Transmissivity How much water can be moved horizontally –Function of thickness and K sat –Good measure of well productivity –Floridan is the most transmissive aquifer in the world

7. Loss of Potential

11. Potentiometric Surface Elevation of “free water surface” Where this surface and the ground intersect (and there’s no confinement) water seeps

14. Relevant Questions Where is the water going? –Potentiometric (piezometric) surface How much water is moving? How quickly? –Potentiometric surface and Darcys Law What level of natural assimilation is occuring? –Water quality modeling

15. Gainesville’s Well Field Also Lake City Jasper Geology Land use Conservation Easement

16. Murphree Wellfield Cone of Depression 1988 (Observed)2010 (Predicted)

17. How to make a sinkhole Pray for lots of Rain Suck a lot of water

18. Drilling and pumping Developed into a hole 300ft deep and 300ft wide Hundreds of sinkholes developed over a period of 6 hours.

19. Freeze Protection To protect strawberry yield during a January freeze in 2010, ~ 2 billion gallons per day of water pumped over a 5 day period. Voila.

20. Invasion Fire Subsidence Degraded wildlife habitat

21. Artesian Springs Where a confining layer exists, there may be a pressure potential in the aquifer HIGHER than the gravity potential of the surface. When tapped, water flows upwards

22. Soil water movement across a watershed boundary. P=Q+ET+G+ΔS Q groundwater = K A ΔH/L Darcy’s Law Darcy’s law is mostly used to calculate vertical leakage through a clay layer, but may also be used to calculate lateral flow. Q is water crossing the defined area of the boundary in m 3 /day

23. K is hydraulic conductivity Most meaningful as saturated hydraulic conductivity K sat (m/day). Why? Q= K A ΔH/L

24. ΔH is the difference in H between two points Water flows from high ψ total to low ψ total (could be “up”) PointψGψGψPψPH A B C H = Ψ gravity + Ψ pressure H = level of water in an open well above some datum H A = ? H B = ? ΔH = ? Flow Direction?!?

25. H @ D? H@F? ΔH? Direction? 10 9 8 7 6 5 4 3 2 1 0

26. ΔH AD? Dir? ΔH BF? Dir? ΔH AF? Dir? ΔH/L BF?

27. Q=K A ΔH/L K?A?ΔH?L? Vertical leakage problem Ksat=0.001m/d Watershed=100 ha 0 1 2 3 4 5 6 Datum

28. Q = K * A * ΔH/L K = 0.001 m/d A = 100ha = 1,000,000 m 2 ΔH = 5-3 = 2m L = 2m Q = 0.001m/d x 1,000,000m 2 x 2m / 2m Q = 1,000 m 3 /day or 365,000 m 3 /year Q surface depth = 365,000 m 3 / 1,000,000 m 2 = 0.365m

29. Q=K A ΔH/L K=0.1m/d A=100m x 50m =5,000m 2 Δ H=108m-105m =3m L=1,000m Qm 3 /d= 0.1m/d * 5,000m 2 *0.003 = 1.5m 3 /d Lateral leakage problem

30. Groundwater Flowpaths at Streams

31. Groundwater Discharges

32. Groundwater Flowpaths

33. Next Time… Soil Water Storage