Recap of 2006-2007 sheetflow season for Big Cypress National Preserve
SFL Weekly Watersheds Summary: March 19 – 25

WEATHER. Some rain swept through the southern edge of the peninsula this past week. It drenched the southeast corner of Big Cypress National Preserve where rain gages recorded over 2 inches at Pinecrest and Lime Tree Hammock. Water levels in the southeast portion of the preserve rose over 6 inches as a result. However, the storm as a whole didn’t have much of a wide reach into other basins. Even the central and north parts of the preserve were relatively rainless just a couple 5 miles away. Preserve-wide around 0.8 inches of rain fell for the week. Most of the rest of the District, including the Naples and Ft Myers areas, were also dry for the week.

BIG CYPRESS. Now that preserve-wide stage has dropped below the bottom of our swamp forest and marsh wetland habitats, its a good time to look back in full at a quick snapshot of the 2006-2007 sheetflow season. We had a relatively late start to the sheetflow season this year due to below-average June rains. Eventually, the wetting front shot up sharply in September following the deluge from Ernesto. It’s probably that rapid rise from dry to deep waters from a single storm event that contributed to such a light touch of mosquitoes again this year. A similar rapid flooding at the outset of 2005’s wet season also contributed to quick and widespread dispersal of gambuzia into every nook and cranny of mosquito breading hideouts. The Ernesto rain event pushed the wetting front up into the preserve’s mesic pines where it stayed for the next 1.5 months. However, an early end to the summer rainy season and the absence of fall-season tropical activity put a decisive early end to the 2006 wet season. Water levels were in fast retreat through October and November. By late October the wetting front receded out of the hydric pinelands into the wet prairie habitat and by mid November the sheetflow season of flowing water came to a close. Preserve-wide water stage held steady for much of December at the transition between wet prairie and tall cypress, before dropping steadily through January, holding again relatively steady for the month of February at the transition between tall cypress and swamp forest before starting its final descent below swamp forest habitat by the middle of March.

In terms of hydroperiod duration, the wetting front crept into or above mesic pinelands for 1.5 months, and inundated hydric pines for 2 months, wet prairie for 6 months, tall cypress for 7.5 months, and swamp forest and marsh for 8.5 months this year. Compare that to 2005 (the year of Wilma) when mesic pinelands were flooded for 4.5 months, hydric pinelands for 6.5 months, wet prairie for 9 months, and swamp forest for 9.5 months. In terms of flowing sheetflow, this year’s sheetflow season of flows in excess of 1000 cfs measured under US41 (by the US Geological Survey) lasted for only 3 months in comparison to a 7-month duration for the previous year. Don’t forget that in 2005 the sheetflow season was stretched at its ends by record June rainfalls at the onset of the rainy season and a late exclamation point to the wet season from Wilma. This year’s wet season started late and ended early, but did achieve a short-lived glory in the middle by the bumper crop of rain from Ernesto.

Where that that put our current conditions? This year’s dry season marks the third consecutive “dry” dry season, which has meant a quick pace for the dry season recession. Now that water levels have dropped into the shallow aquifer, we’ve officially entered the into the heart of our dry season. Preserve-wide stage dropped about 4 inches per month for the first 5 months of the dry season. However, for the remainder of the dry season (barring significant rains) the drop in water levels will accelerate to around 12 inches per month due to a combination of increased evapotranspiration and the physical displacement of the water surface into the top of the aquifer.

Currently, preserve-wide stage is marking a new 5-year low for late March. Current preserve-wide stage is about 10 inches below our 5-year average for late March, and about 4 inches below late March of last year.

0 0 votes
Article Rating
Notify of

Inline Feedbacks
View all comments
Would love your thoughts, please comment.x