The above hydrograph shows a regional water level summary for Big Cypress National Preserve. The graph is vertically color coded to represent the major ecohydrologic habitats in the preserve: dry season refugia pools being the lowest lying and pinelands being the highest in elevation. The dotted white line shows the 20-year median elevation. The blue line shows the current level. As you can see, pond apple forests are in general flooded in most areas of the preserve, despite drier conditions prevailing north of Alligator Alley and Okalocoochee Slough.