WCA - Everglades Conditions Update

(May 27, 2008)

 

Rainfall:

Most of the rain this past week was confined to the northern reaches of the Greater Everglades (see attached gif) and is reflected in the totals shown below. Despite the relatively high rainfall totals, only WCA-1 exceeded the average weekly total ET of 2.2” (see srs.pdf).

WCA-1:          2.94”               WCA-3A:        1.22”

WCA-2A:       1.42”               WCA-3B:        1.19”

WCA-2B:       1.95”               ENP:                0.39”

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Water Conservation Areas:

After some four weeks of good recession rates in support of wading bird nesting, recent rains, especially in the north, have caused water depths to increase by as much as a quarter of a foot. Recession rates were poor or fair almost everywhere and water depths remain above optimum (optimum = 0.1’ – 0.79’) for foraging by wading birds (see attached WCA Stages.xls). Stages increased throughout the WCA’s, but continue to decline in ENP. Stages are slightly above regulation in WCA-1, well above Regulation in WCA-2A  and slightly below regulation in WCA-3A  (see WCA_reg_stages.doc).

 

Everglades National Park:

Rainfall was patchy across ENP and FL Bay last week, with 7 d accumulations across the wetland and marine stations measuring between 0.1 – 0.7.  This spatially variable pattern was reflected in last week’s trends for ENP wetland water levels, down across much of the area except in the panhandle where rainfall totals were higher (1 – 2” based on RAINDAR estimates).  Water levels dropped by a meager 0.3” again this week in Shark River Slough (station P33, recording 0.2” of rain for the week), which is not much considering the high temps/ET of late.  Taylor Sl. Bridge posted a weekly decline of 1.9” (not an unusual recession rate at this station).  The most dramatic recession was again in the southern part of Taylor Slough (at Craighead Pond), down by nearly 3” for the third straight week.  As mentioned, the panhandle was the only area to show increasing water levels, up by 1.8” at station EVER6.

 

Modest rainfall buffered the persistent strong southerly winds and high rates of evaporation last week, allowing salinity in much of Florida Bay to remain fairly stable.  Concentrations herein described should be near their seasonal peaks, unless the rains don’t kick in soon (in which case salinity will continue to climb).  Salinity held steady in the northeast Bay, reading in the upper 30s at Trout Ck & Long Sound/Highway Ck., and the middle-30s at the mouths of Taylor River & L. Madeira Bay.  In the Taylor ponds, daily mean salinity remained over 30 psu at Pond 5 (USGS station) and Argyle Hendry (ENP station TR) for another week.  As of Sunday, 5/25, the 30d moving average concentration at TR (used for tracking the FL Bay MFL criterion) was at 30.4 psu (up from 28.2 psu last week).  Low rainfall, strong winds, and high ET across the region have facilitated daily mean concentrations exceeding 30 psu for 18 consecutive days at TR (see Salinity.pdf), so it is not surprising that we surpassed the 30 d running average criterion of 30 psu on Sat., 5/24.  Salinity held near 40 psu in the northcentral Bay areas of McCormick Ck. & Terrapin Bay.  The central Bay station in Whipray Basin, though, posted a substantial salinity increase last week, up into the mid-40s.  Salinity in the upstream reaches of Shark River (Tarpon Bay platform) measured above the seasonal norm (mid-teens), moving up into the mid-20s last week.

 

Wildlife:

Nothing new to report.

 

 


 

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