WCA - Everglades Conditions Update

(April 29, 2008)

 

Rainfall:

Very little rain fell last week across the Everglades (see attached gif), ranging from 0.01” to 0.08”:

WCA-1:          0.03”               WCA-3A:       0.03”

WCA-2A:       0.02”               WCA-3B:        0.01”

WCA-2B:        0.08”               ENP:               0.01”

The mean 7 day evapotranspiration for the region was 1.58”; see srs pdf.

 

Water Conservation Areas:

Recession rates in the conservation areas improved somewhat last week with low rainfall, high evapotranspiration and water management releases.  However, recession rates are highly variable across the region (see WCA_stages.xls), best for wading birds in parts of WCA-1, 3A, and 3B.   WCA-2 recession rates are poor or fair.  Most of the conservation area water depths remain well above the 1 ft maximum threshold for wading bird foraging. Stages in WCA-1 have declined but are still above Regulation Schedule (see WCA_reg_schedule.doc), WCA-2A marsh remains more than 1’ above regulation, and WCA-3A stages continue to decline.

 

Everglades National Park:

Very little rain fell across ENP and Florida Bay last week again, producing another week of declining water levels across the ENP wetlands. 

 

Salinity is rising across the Bay and mangrove transition zone, but concentrations are not abnormally high (i.e., this is typically the time of year when salinity concentrations can rise rapidly with conditions of no or low rainfall or incoming flow, and high evaporation).  Nearshore areas of Trout Creek, Taylor River mouth, and Little Madeira Bay are all reading near 30 psu.  Salinity in the Taylor ponds increased slightly for the week, into the upper 20s at Pond 5 and Argyle Hendry (station TR, used for Florida Bay MFL reporting); the 30 day moving average concentration at Taylor River increased slightly, up to 20 psu as of Sunday, 4/27 (up from 17.5 psu in last week’s report).  The central Bay salinity also increased this past week, into the mid-30s at Terrapin Bay and McCormick Creek, and into the upper 30s at Whipray Basin.  Except for the ponds, these concentrations are near their earlier concentrations before the rain events this month, and all areas (including the ponds) are well within seasonal norms.  Salinity remains high out west, downstream of Shark River Slough at Tarpon Bay (where salinity was back in the mid-teens as of Sunday, 4/27), but given the time of year is not too high (unlike earlier this dry season when this area experienced higher than average concentrations). 

 

Wildlife:

Water depths remain limiting to wading birds over much of the system, but have improved slightly since last week with the high ET and low rainfall.  Recession rates have also improved a little since last week, so they may stimulate some nesting in White Ibis.  Last Friday’s survey was cancelled so there is no update on specific nesting activities.    

 

While current high stages may not be conducive to successful nesting, they may be necessary for populations of fish, crustaceans and apple snails to recover from recent drought conditions.  

 

Fires 

Multiple fires were reported last week (NASA Fire Information for Resource Management System) on Wednesday in central WCA-3 and on Friday in southern WCA-1 (see attached Fire.doc)

 

 

 


 

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