ILLUSTRATIONS

Figure Page
 1. Map of Florida showing location of Escambia and Santa Rosa counties 5
 2. Graph of rainfall at Pensacola, Fla., and Brewton, Ala., showing monthly
 averages, maximums and minimums, and yearly rainfall for the period
 1926-61 ___ 7
 3. Map of Florida showing the well-numbering system 8
 4. Geologic sequence in Escambia and Santa Rosa counties, as shown by
 representative log of oil test well near Pensacola 10
 5. Map of Escambia and Santa Rosa counties showing locations of selected
 wells from which information was obtained and the water supplies that
 can be developed from wells in the sand-and-gravel aquifer __ 10
 6. Geologic section across Escambia and Santa Rosa counties showing aqui-
 fers and aquicludes along section A-A' in figure 11 _12
 7. Geologic section along the Gulf Coast from Mobile Bay to the Choctaw-
 hatchee River showing aquifers and aquicludes 14
 8. Geologic section showing faces changes and zones of relative permeabil-
 ity and impermeability in the upper part of the sand-and-gravel aquifer
 along the Perdido River, Escambia County ____ ______ 15
 9. Map of Escambia and Santa Rosa counties showing contours on top of
 the lower limestone of the Floridan aquifer 18
 10. Map of Escambia and Santa Rosa counties showing contours on top of the
 Miocene clay units -_ --- 20
 11. Map of Escambia and Santa Rosa counties showing contours on top of the
 Bucatunna Clay Member of Byram Formation __ 22
 12. Approximate average annual runoff, in inches, from areas within Escam-
 bia and Santa Rosa counties __----- 26
 13. Runoff in inches for 1961, a year of high runoff, and for 1956, a year of
 low runoff, from areas within Escambia and Santa Rosa counties --- 27
 14. Basin map of Perdido, Escambia, Blackwater, and Yellow rivers _--- 28
 15. Graph showing periods and types of surface-water records in and near
 Escambia and Santa Rosa counties ___ __- 29
 16. Map of Escambia and Santa Rosa counties showing surface drainage and
 data-collection points _-- ---------- 30
 17. Flow-duration curves for 5 streams in Escambia County 31
 18. Flow-duration curves for 5 streams in Santa Rosa County -- 32
 19. Channel-bottom profile for lower Perdido River ------- ---- 33
 20. Regional flood frequency curves for the Perdido, Escambia, Blackwater,
 and Yellow rivers _- ---- 35
 21. Low-flow frequency curves for Perdido River at Barrineau Park,
 1941-61 __ 36
 22. Graph of the minimum, average, and maximum monthly discharge of
 the Perdido River at Barrineau Park, 1941-61 37
 23. Channel-bottom profile for lower Escambia River 41
 24. Channel-bottom profile of Pine Barren Creek ----- --42
 25. Discharge available without storage, Pine Barren Creek near Barth,
 1952-61 _____ 43
 26. Mass-flow curve for Pine Barren Creek near Barth, 1952-58 44