June giving us a rainy start to the wet season
SFL Weekly Watersheds Summary: June 11 – 17
JUNE RAIN. Last week was a very rainy week, especially for stretches of south Florida south of I75. District-wide, around 6 inches of rain has fallen for the month, which is still about 2.5 inches below rainfall totals for the past 10 Junes. Miami-Dade totaled 5 inches for the week. That’s more than half its total June average of 9 inches, which is also Miami-Dade’s 10-year June average. Big Cypress National Preserve, currently chiming it at 8 inches of June rain, has already equalled last year’s June rainfall total. The preserve’s long-term June average is 10 inches, so we still need a little more rain in the next two weeks to meet or exceed our June average.
BIG CYPRESS. Three rain gages in the preserve have received over 12.5 inches of rain over the past 30 days: Oasis, Gator Hook Strand (south of HP Williams), and Gum Slough (south of Loop Road). Wetland water stage at Gum Slough is currently about 3 inches higher than at the same point during our record-breaking June 2005 deluge, when 20 inches fell for the month. From a preserve-wide perspective, wetland water levels are rebounding right in tune with the long-term June trend. That puts preserve-wide stage at the brim of our tall cypress strands and domes, and on the cusp of overflowing into our wet prairies. Preserve-wide water levels have now risen 2 ft from the fire-scorched nadir in late May. Keep in mind that the area south of US41 is the wettest — with the wetting from moving into the hydric (and even mesic) pineland elevation, but the area north of I75 still playing catch up — with water levels still perched in the deepest swales of its swamp forests and marshes.
EVERGLADES. Regulatory stage in 3A has jumped 10 inches since its low-water nadir in late May. Regulatory stage is currently tracking about a half foot below its 5-year mid June average, and about the same level as mid June of last year. The big news is that the S12D is scheduled to open this week. That marks the first water release from the S12s when S12D was closed 6 months ago in mid December 2006. The rest of the S12s were closed in late October and November. Currently, about a half foot of water is pooling behind the S12s and over 1.5 ft of water is pooling behind the S11s. Over the past 5 years, the S12s and the S11s typically start exceeding 1000 cfs by July. Of interest, water slough water depths in both the Park’s Lostman’s slough (at P34) and in 3B (at Site 71) are currently deeper than in southern 3A (at Site 65). That’s a relatively rare occurrance. Typically Site 65 is higher. For example, Site 65 peaked at a +3 ft slough depth last October, in comparison to 2.5 and 1.5 ft slough flooding depths at Site 71 and P34, respectively. Regulatory stage in Loxahatchee is currently tracking right in tune with the 5-year mid June average. That puts slough flooding depths nearing their brims and starting to overflow into the ridges. Regulatory stage in WCA2 is currently tracking about 9 inches below its 5-year mid-June average. That puts water levels at the bottom or below the slough land surface.
LAKE O. As of Sunday, Lake O stage was still tracking a notch below 9 ft msl. That’s 3 ft lower than mid-June of last year, and 4.5 ft below the Lake’s 5-year mid-June average. The heaviest portions of this year’s rain has fallen in the southern Everglades, which hasn’t helped restore Lake water levels or kick-start Kissimmee flows. The Lake has only received 4 inches of rain for the month of June so far, in comparison to its 7 inch long-term June average. In comparsion, the Kissimmee Valley has received about 4.5 inches of June rain so far, and averages around 8.
When will the Lake stage rise into its perimter littoral zone? During the record-drought year of 2001, Lake stage didn’t do that (rise above 13.5 ft msl) until October. In 2002 it was late July.
In 2003 it remained flooded all year, and never dried down. In 2004 it was September. In 2005 it stayed flooded all year as well, with only a brief month-long drydown in late May. In 2006, the littoral zone went dry in April and did not flood for the remainder of the calendar year. That puts us in our current condition. Its been 14 consecutive months since water levels overlapped the lake’s interior littoral zone at a 13.5 ft msl elevation. That’s 4.5 ft higher than current Lake stage.