>>Um, so let’s talk a little bit about sand
and water and this is really thinking about physics of the Ridge. Usually when you see
a watershed map, people always draw up the rainfall in the mountains, and it goes down
the rivers, into the estuaries, out into the sea, it evaporates back, and the whole cycle
starts again. Well, the Ridge is a little bit different from that. We have lots of evaporation, that’s evaporated
water coming off open water surfaces like seasonal wetlands or a lake. We have water
coming out of the transpiration of plants – when plants give off water as they open
their little stigmata and leaves. We also have lots of water coming from adjacent wetlands
off the Ridge — the Ridge acts as sort of a system where wet, moist air rises over the
Ridge and lots of precipitation as a result of that. That’s the water cycle here on the
Ridge. What happens when that precipitation falls
on the Ridge? Well, some of it, particularly if the sand is very wet, will run off into
little seasonal wetlands. A lot of it infiltrates down through the sand; you can think of it
as the biggest sandy water tank in the region — think of the Lake Wales Ridge as a giant
kid’s sand box that’s often full of water. Of course when you fill up a big sand tank
like that, it releases water slowly, it takes a long time to fill up, water goes down – and
we’ll talk about that in a minute – and water also goes outside this sand box. So, when
water rains (pause – laugh) when rain falls on the Lake Wales Ridge, we get a lot of infiltration
into the sand. And that can go either into the first aquifer system we have which is
called the surficial aquifer, the one right below your feet. In some parts of the Ridge
it might be just two or three feet below you, in other parts of the Ridge it might be eighty
or ninety feet down before it hits water. On Archbold around the station, those of you
that are familiar, the surficial aquifer – which is shown by this line here – is only, at
the weather station, maybe six to ten feet down depending on the time of year . If we
go to our high point on the station, which is the red hill, it’s eighty to ninety feet
down, so it depends a bit where you are on the Ridge as to how far down is the surficial
aquifer. The rain falls, seeps through here, and may
often seep sideways into seasonal wetlands. All those little seasonal wetlands we have
— yes of course they are charged by rain coming on into the wetland — but there’s
also a lot of seepage from the surrounding sands into these low points. By low points,
I’m often meaning one to two feet lower than where you’re standing in the Ridge system.
There’s a lot of seepage this way. After it’s been dry for a while, what happens to those
little seasonal wetlands is the water then leaves them and seeps out, back into the sand
and down; they’re sort of like little saucers filling up, releasing the water, filling up,
releasing the water. Some of the water actually infiltrates through
our surficial aquifer and keeps going down and may, go through these – there’s a series
of breaks through the sort of clay layer, called the confining layer – and may go down
into the intermediate aquifer (and I’m going to talk about the Floridan aquifer next).
But I want you to think of a system where there’s this big sand box, there’s a lot of
seepage and movement down on the sand box and the other thing that happens is water
seeps off the side of the Ridge and we’ll come to that in a little bit. But when you
think about water moving on the Ridge, think about it moving down, moving laterally, and
then eventually often seeping off the side of the Ridge on the East side or the West
side. So when you come off the Ridge — when you drive over Highway70 or Highway 60 and
you feel yourself diving off the Ridge — when you get to the bottom of that, the toe of
the Ridge is a very wet place. That’s where all the bay heads are, that’s where all the
deeper, peat-ier soils are. So the Ridge releases water sideways and it seeps out as well as
releasing water down. If you had been here 100 years ago, you would have found deep bay
heads all the way up and down the East and the West side of the Ridge. Many of them have
been cleared, but the Ridge used to be bordered by very deep, peat bay heads – these are
wetlands that are dominated by bay trees – so that was the edge of both ridges, at the bottom
of the Ridge.