Understanding Lake O’s Historic Flow; What were Transverse Glades?


South Florida’s southern Everglades, 1850 vs. 2003 similar to 2019. Image courtesy of SFWMD, based on the book Landscapes and Hydrology of the Predrainage Everglades, McVoy, Said, Obeysekera, VanArman, Dreschel, 2011.

Today I share a familiar set of images. Although we have seen many times, they remain mind-blowing. Don’t they?

~Yellow lines outlining Florida’s original Everglades’ River of Grass contrasted to today’s highly human impacted, managed system.

What one may not notice, are the “Transverse Glades” labeled on the lower right area of the Pre-Drainage image? There are two types: “Peat Transverse Glades” and “Marl Transverse Glades.”

So what are they? Or better said, what were they? And what do they mean?

“A Transverse Glade is a surface-shallow groundwater drainage pathway moving water out of the main Everglades Basin and controls the Everglades water table.” (Ogurcak, https://conference.ifas.ufl.edu/GEER2008/Presentation_PDFs/Additions/THURSDAY/Meeder-Thursday-Transverse%20Glades%20Karst.pdf)

These transverse glades would have been moist in the dry season and could be totally inundated during the wet season as they allowed the waters of the Everglades Basin to slowly seep/flow out.

Following Nature’s hand, the first canals built to Lake Okeechobee from the coast were started or ended in these areas. The early settlers used the canals not just for drainage, but also for transportation to and from the Lake and surrounding areas.

The first canals constructed were the North New River Canal  (1906-1912) connecting to today’s  Ft Lauderdale in the area where the peat transverse glades were located; and the Maimi Canal (1910-1913), in the area where the marl transverse glades were located. Both the New River and Maimi River were neighbors of the transverse glades. Makes sense doesn’t it?

Early Post-drainage 1910, Harshberger image, 1913.


One would never even guess the transverse glades ever existed thinking all the water flowed out of Shark River Slough and Taylor Slough. Not the case when we look back far enough; we can see Mother Nature’s design. Interesting isn’t it?

Facility & Infrastructure Map, SFWMD 2019
Plate 5, Landscapes of the pre-drainage Everglades and bordering areas, ca. 1850. Courtesy: Landscapes and Hydrology of the Predrainage Everglades, McVoy, Said, Obeysekera, VanArman, Dreschel, 2011.
Figure 11.12 Landscapes of the pre-drainage Everglades and bordering areas, ca. 1850. Courtesy: Landscapes and Hydrology of the Predrainage Everglades, McVoy, Said, Obeysekera, VanArman, Dreschel, 2011.

Google Earth 2019

See for explanation of peat and marl soils: https://www.nps.gov/ever/learn/nature/evergeology.htm

See Chapter 10, peat and marl transverse glades: https://www.academia.edu/13200912/Landscapes_and_Hydrology_of_the_Predrainage_Everglades-Overview

11 thoughts on “Understanding Lake O’s Historic Flow; What were Transverse Glades?

  1. Great post. These maps show the details often ignored regarding traditional flow “south”. The topography obviously sends most flow to Shark River Slough. See the small “basin” below the marl and cut between what would be two “Keys” (if the sea level was higher) that feeds Taylor Slough. The fact that today the levee on the east side of Taylor Slough has water seeping when the Park side is wet would indicate some water flowed west from small basins on the east side into the Slough as well. But, all together not a lot of fresh water flowed from the north into Florida Bay. For some reason, this obvious natural flow does not want to be accepted by some adherents to the “Florida Bay needs more (a lot more) fresh water from the north. The topography supports the position that the salinity of Florida Bay was (and is) rain driven. Interesting, as I was a firm believer in the mantra! Newton

    Sent from my iPhone


    1. Thank you Newton. Very interesting observations. I am glad you liked the post. From my studies, I would think that when Lake O was at 22 feet running over the lake’s southern edge through the custard apple rim into the sawgrass marsh, gushing water during a high rainy season, the water did indeed go over the ridge into Florida Bay. Don’t you think? Certainly,​ southern rain would make this more so but I would not think it was entirely rain driven going to Florida Bay. That Everglades basin was really high sometimes- like 3-6+ feet in some places….? Very weird to think about today! 😊

  2. so interesting Jacqui! love the history lesson and graphics, Really gets to the heart of the problem from the north end of Okeechobee to the keys was really slough and wetland with a few ridge exceptions. Very good read and display

  3. On the Florida chanel I see where the head of FWC is retireing. Of course lie detector test can not convict a person of a crime but I think if 10 or more co-workers can not pass a lie detector test then they should be found guilty. I would like to ask did FWC play a role in destroying Florida;s estuaries?

  4. Water is not like air in that it does not compress. All the river of grass makes resistance to water flow. If 10 miles = 1 inch on your map you can do an exsperament. 60 miles to lake o. would = 6 inchs. 150 miles from lake O. to Florida Bay would = 15 inchs. Now on a flat levil table put a porus “sponge”. 6inchs on the Stuart side and 15 inchs on the everglades side. Pour water in the simulated lake O. and see where the water goes.There are a lot of competitors who would like to destroy our winter vegitable farmlands.

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