Water Years 2021/2022 in Review
A brief comparison of the past two years

1. Water Year 2021 (May 1, 2020 to April 30, 2021)

Water Year 2021 classified as above average in terms or rainfall, recording 46 and 14 inches of wet and dry season rainfall, respectively, for a total of 60 inches.  The summer wet season started early with a June-like rain total in May (8 inches) and ended late with above average rains in October and a surprise storm in November.  Of note, the early start was not enough, or rather in time, to prevent a destructive incineration of an archipelago of hardwood hammocks in the southeast Corner of Big Cypress National Preserve called the Moon Fish Wildfire.  Within a week of the fire ending the May rains swept through.  Near normal rainfall persisted for core four months of the summer wet season (June through September) and were supplemented by a “wet season” like October.  But the real exclamation point came in November in the form of Tropical Storm Eta, filling the Everglades and Big Cypress Swamp to levels last seen in September 2017 from Hurricane Irma, only shifted forward two months to a time when water levels are usually well past their October peak. 

Firelight Radio is available on Apple Podcasts and Podbean

The late season highwater stand set the stage for or prolonged and steady winter recession that proved to be a boon to wading bird communities in terms of foraging and nesting.  Despite expectations of a wet dry season from the bumper crop of summer and late fall rain, the Big Cypress Swamp dropped into deep drought by April’s end.  Although no similar wildfires occurred, Water Year 2021 proved an important restoration point:  No matter how wet the wet season or the beginning of the dry season, without timely April and May rains the Big Cypress Swamp is especially prone to dropping into deep, unnatural drought due to perimeter and interior canals that stifle the spread of sheet flow and hasten its spring demise. 

2. Water Year 2022 (May 1, 2021 to April 30, 2022)

Despite the previous year’s bountiful rains, Water Year 2022 took started slow thank to subpar rains in May – extending drought conditions into June and even July in some area.  However, the four core seasons of the summer wet season (June through September) and October all charted in with average rainfall.  For a second year in a row, November provided an unexpected boost with twice its normal rainfall amount. Again, despite the surplus of water at the dry season’s start, the Big Cypress Swamp was poised to drop into deep spring drought, imperiling the habits that so vitally depend on natural fire breaks staying wet, when a string of continental fronts at the middle and end of April and start of May boosted the water table just when it needed it most.  South Florida received over 10 inches less annual rainfall and 4 inches less dry season rain than the prior year, but it is as much an issue of timing as it is the total amount. Water Year 2021 classified as low normal in terms or rainfall, recording 36 and 12 inches of wet and dry season rainfall, respectively, for an annual total of 48 inches. 

Share with friends

Did You Know: Up north on the continent, the water year starts October 1st and ends September 30th in most areas.

3. Additional Discussion

Of interest, despite the apparent disparity between Water Years 2021 and 2022, as judged by their annual rainfall of 60 and 48 inches, respectively, the first classifying in the “above normal range” and the second in the “low normal” range, the two years acted similarly in some respects, and defied the norms of previous years in several respects.  The “old normal” of too much water in Water Conservation Area 3A, not enough water in downstream Everglades National Park (as limited through the S-12s), and a deep spring plunge of the water table below the cypress roots in the Big Cypress didn’t materialize for either year.  Instead, three new bridges along the Tamiami Trail opened the door for increasing the flow of water into Northeast Shark River Slough and downstream Florida Bay, as also supplemented by the S-332 water retention barrier on the Park’s east side.  As a result, sloughs in the Park stayed flooded with a foot of water into May for both Water Year 2021 and 2022; whereas similar sloughs in Water Conservation 3A dropped below the one-foot depth threshold by March.  Also in a reprieve from previous years, timely spring rains helped keep drought in check in the Big Cypress Swamp.

Water Years 2021 and 2022 highlighted the benefits that increased operational control afforded by the growing list of water management infrastructure projects have towards achieving a broad spectrum of Everglades Restoration goals.  Recent notables include Lake Okeechobee’s strengthened levee, bridging and now raising the Tamiami Trail grade along Northeastern Shark River Slough, and opening of the C-44 Reservoir, improved seepage control along the L-31 just to name a few, with many more projects and planning initiatives in various stages the way including the Biscayne Bay Southeastern Everglades Restoration (BBSEER) and the Western Everglades Restoration Plan (WERP).  Modernization of the water management infrastructure combined with availability of real-time data to inform operations took a major step forward over the past two years. 


The Everglades and Big Cypress Swamp are flood and fire adapted ecosystems in which every square inch of flora and fauna depend on a regular return interval and dosage of both flood and fire.  Or as the saying goes – so goes flood and fire, so goes the swamp.  As proven these past two years, operational stewardship is vital to getting both right. 

0 0 votes
Article Rating
Notify of
Inline Feedbacks
View all comments
Would love your thoughts, please comment.x