2006 Wet Season approaches final month
SFL Weekly Watersheds Summary: Sep 18 – 24

Lake O. Lake stage has held steady at the bottom of the littoral zone (13.5 ft msl) for the past 2-3 weeks. In comparison, by late September of last year Lake stage had steadily dropped down to the top of the littoral zone (15.5 ft msl) after a July peak of 16.6 ft msl, but that decline proved to be short-lived and was followed a few weeks later by Wilma and a 1.5 ft rise to 17 ft msl. Inflows and outflows from the lake are relatively non-existent in comparison to recent years. Over the past 5 years inflows from the Kissimmee River peak in September at +5,000 cfs, but this year are tracking under 1,000 cfs, having peaked just above 3,000 cfs following Ernesto. Over the past 5 years, discharge through the S79 WP Franklin dam have averaged around 5,000 cfs from July through September. Other than this year’s +15,000 cfs spike following 7 inches of Ernesto rain in the East Caloosahatchee basin, this year’s S79 flows have been tracking well below that average, and none of the discharge has been from the Lake.

3A. Regulatory stage in 3A has risen about 1.5 ft since Ernesto and is now tracking about an inch below last year’s late September level and almost identical to the 5-year average for late September. Keep in mind that last year the real difference-maker was the early onset and of tree island inundation and persistence of those conditiosn through the wet season and into the fall and winter. Since June, this year’s regulatory stage had been tracking about a foot lower than the 5-year average, and only now a month following Ernesto have water levels rebounded upward to coincide with the 5-year average for late September. Interestingly, last year Wilma passed over 3A with little rainfall. Unlike the Lake that had a double camel hump rise in stage (the first following the record June deluge and the second following Wilma’s drenching of the Kissimmee basin), stage in 3A receded in close unison with the 5-year average from October through the winter and spring. In total, regulatory stage stayed above 11 ft msl for 5 months last year (Jul through November), whereas this year stage in 3A has been above 11 ft msl for 2 weeks to date. The S11s are currently flowing at 3,000 cfs, which is about twice the average rate for late September. The S12s are currently flowing at 2,000 cfs, which is just under the 2,500 cfs late September average. On the average year the S12s flow for 7 months from late June to late January, cresting at an average of 3,000 cfs in mid October. The S12A is usually the first and last gate to open. This year it openned in early September. The year before it openned in late June. Last year it was closed in mid November, but more typically closes at the start of November.

Big Cypress NP. Preserve-wide, water levels have held steady at the mesic landscape type, and are currently tracking 1 inch above the 5-year average for late September, and about 3 inches above late September of last year. Keep in mind that last year was wetter overall in terms of total duration of mesic wetland flooding due to the early and fast rise of surface waters following last year’s record June rainfall, and the then bookended by the late wet season Wilma boost to water levels. As a result, water levels flooded up to and above the mesic landscape type for 5 consecutive months last year. Water levels did not break the mesic plane until early September of this year following Ernesto. Water levels are currently deepest in the Bear Island area of the preserve, at about 1 ft higher than late September of last year.

ENP. I’ve updated the watershed summary for ENP. It now shows an improved interactive map. Click on the “view big map” tab at the top right hand of the page to view an enlarged map of the Park. P33 is currently tracking about 0.5 ft lower than the 5-yr late September average, and about 0.75 ft below late September of last year. Water depths in the Park are tracking about 1.5-2 ft lower than on the north side of US41 in 3A at Site 65. Inflows across the Big Cypress NP portion of the trail are currently accounting for 2/3rds of the headwater inflow to the Park. Interestingly, freshwater flows under the Big Cypress NP portion of the trail are currently tracking about 1,500 cfs above the 5-year wet season average, whereas flows through the S12s are currently tracking about 500 cfs below the 5-year wet season average.

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