Where Go Hydrology translates data into useful images

Odd structure out?
S-12A flows less than B, C and D

Here’s a look at discharge …

Into Everglades National Park through the S-12A.

Historical discharge calendar for S-12A

Actually, that’s incorrect. In addition to the Park, it also flows into the southeast corner of Big Cypress National Preserve. To the west of Shark River Slough, separated by Rattlesnake Ridge, is another flow way called Lostmans Slough. Long ago, when the Central and Southern Florida (C&SF) Project was being designed, there were plans to extend the L-28 ten miles south and another ten miles west, or basically, short circuit water around Lostmans Slough. Fortunately, that never came to fore. But, we can’t forget, just like Shark River Slough needs its water, so does Lostmans Slough as well. This year it didn’t get much. As you can see in the chart above, the S-12A was barely opened at all.

The S-12s consist of four structures in total: A, B, C and D. The structures look the same and are spaced about 3 miles apart. To me, whenever I drive by it, I always wonder what it would say if it could speak. The above calendar chart provides a possible translation.

Video of the S-343B and S-12A

One last thing about this structure: I also regard it as a mile marker. The L-28 is the modern-day boundary between the Everglades and Big Cypress ecosystems, but it’s hidden behind a hedgerow of trees. The S-12A is impossible to miss, as is the giant grove of cypress trees called Big Cypress National Preserve as you continue west.

Bar chart dynamics
How to read a monthly rain chart

South Florida has two distinct meteorologic seasons:

A 6-month wet season and a 6-month dry season.

How to read a rain chart

Things you should know: (1) The water year begins anew the start of May each year. But it’s not an exact science (i.e. precise point) when they start and end from one year to the next. For example, we classify October as a wet season month even though the afternoon rain showers usually end in early October. And the start of May is probably the swamp’s driest time, yet it’s also the same month, as it approaches June, that the summer rainfall pattern begins. (2) Most of my rainfall charts show background gray coding. That’s the historical statistics as counted from 1983 to present. Why 1983? It was a good year, and most of the SFWMD’s record by basin reaches back that far. Looking at the chart above, the dark gray band is the average range for each month (i.e. between the 25th and 75th %tile) and the light gray is the historic rang (i.e. between the max and min). The white bar in the middle is the normal or median monthly rain. (3) My charts are based on basin-wide rainfall, not local rainfall.

Newspapers calculated rainfall by calendar year. (They are wrong. How dare them!) They also calculate rainfall for an individual gage in Ft. Myers and Naples (The shame!).

In summary, numbers mean more if you can frame them against the expected values and ranges that came before. And its by water year, not calendar year, that we tally rainfall totals in south Florida.


Volume of Deep Lake
Using the BOE approach

There’s a lot of sophisticated models out there …

But my favorite is called the BOE.

Sometimes simple math is the best

That’s short for “Back of the Envelope.”

Using the BOE approach, I estimate there are about 72 acre-feet of water in the approximately conical lake. Or in other words, it holds about the same volume of water as filling the Boston Red Sox Fenway Park up to the top of the 37-ft high Green Monster (i.e. Left Field Fence). The lake is about as deep as the distance from home plate to first base. Or in swamp terms, about two mature cypress trees high. Meanwhile, it holds fifty times the depth of a fully flooded cypress dome. And did you know the lake is meromictic below 75 ft? That means it’s bottom sediments do not circulate to the surface. Compare that to Lake Okeechobee that at a maximum depth of 20 ft it’s 5 times shallower than Deep Lake and constantly circulating its basal sediments back into the water column.