Rain or Shine Report for February 5
Lake Toho is at 55 ft above sea level.
That’s a foot higher than late January of last year, and about 2 ft higher than the late January 5-year average.
But don’t forget that Lake Toho was drained a few years back – to scrape away the benthic muck that had accumulated at its bottom – so that may be skewing the 5-year average in a downward direction.
Wasn’t that back in the start of 2004?
And didn’t that cause an uproar because downstream Lake Okeechobee was so high at the time?
What a difference a few years makes. Now the tables are turned.
Toho is high and Lake O is low.
Now compare Lake Toho to downstream Lake Kissimmee – the original source of the Kissimmee’s river channel (prior to canal building) – which is at 50 ft above sea level. That’s about a foot higher than late January of last year, but it’s right on the nose of the 5-year average for late January.
Further downstream, Lake Istokpoga is perched at just over 38 ft mean sea level. It’s sitting at the same elevation as late January of last year, and around 10 inches below the late January 5-year average.
The dry season marches on: water levels have retreated into the center of the cypress domes and thalwegs of the cypress strands in Big Cypress National Preserve.
It’s still grasping at the final straws above 10 ft mean sea level, but that won’t be for much longer; its just days away from dropping below the 10 ft milestone. Last year The Lake didn’t fall below 10 ft until the start of April, after which it proceeded to stay below 10 ft for a harrowing 6 straight months (from April to early October).
But this summer rains fell short, and when they did fall the clouds tended to produce preferentially along the coastal fringes. The result: The Lake’s summer-fall rise was meager, rising only a half foot above 10 ft at its early Fall apogee.
That means we’re probably in for a similar – if not lengthier and lower – drop below 10 ft this year. It will all hinge on how early the rains come, where they fall, and for how long.
Year after year, we always comment how the one thing you can count on in south Florida is the summer rains. This summer put that rule to a test – both in southwest Florida and over the Lake.
The size of Lake O is somewhat of a misconception. On maps it is delineated by the Herbert Hoover Dike. But about a quarter of the 730 square-mile area is wetlands, and chances are if you approach the Lake from the west shore and look over the edge, wetlands are all you will see.
The wetlands closest to the levee’s western edge are around 15 ft above sea level, with the lowest lying wetlands, the ones at the shore of the open lake, are around 11 ft above sea level, and when lake stage drops below 10 ft, even the deepest of the wetland’s water holes go dry.
By that standard, the highest wetlands have been dry for around 2 years, the middle marsh (13 ft) have been dry for 21 months, and the lowest wetlands – the one’s at the lake shore – have been dry for almost 11 straight months.
But rewind the clock 11 months in reverse – back to March 2007 – and those very same “lake-shore” wetlands (11 ft elevation) were coming off of 6.5 consecutive years of holding water.
That’s typical Florida: droughts, followed by floods, followed by more droughts.
Loxahatchee is tracking normal for late January – or at least normal in relative to the past 5 years.
Sloughs in downstream Water Conservation Area 2 do go dry, almost every Spring. Last year that occurred at the end of February. This year they appear ready to go dry in the front end of February.
The S11s are still discharging into downstream Water Conservation 3, at around 250 cfs, through the S11c structure. The S11s are pooling almost 3 ft of water behind them as well, putting around 2 ft of water in the sloughs on the upstream side of the S11s.
Regulatory stage in Water Conservation Area 3 is around 8 inches below the 5-year average for late January, and around 2 inches below early February of last year. Sloughs in northern WCA3 will probably go dry within a couple of weeks. That means that they held standing water for 6 continuous months. That’s a short hydroperiod for a slough.
Compare that to southern WCA3 where slough depths are around 2 ft deep, and where standing water will likely persist into the heart of the dry season. The last time sloughs in southern WCA3 went dry was for a 2-month stretch in May and June of 1989. That was at the beginning of the first George H.W. Bush’s presidency, and Joe Montana was still in his hay day hurling touchdown passes for the San Francisco 49ers.
Over in Big Cypress National Preserve, the wetting front continues is annual retreat, and eventual disappearing act, before dropping down below ground into the aquifer. Current stage is around 10 inches lower than the 5-year average for early February. That means that this year’s recession is tracking very similarly to the drought of 2001.
In a nutshell, this year’s wetting front dropped out of the hydric pinelands by early November, retreated out of the wet prairies by late December, dropped below the cypress by late January, and is currently making its last stand in the lowest of low-water refugia tucked in the center of cypress domes and along the thalwegs of the cypress strands.
Standing water will hang around longer in the deeper pools of low-water refugia – which become concentrated with aquatic fauna, avian prey, and alligators; but expect many of those pools to dry up considering the pace of this year’s dry down.
And the Big Drought continues — 35 years and running.