WCA - Everglades Conditions Update – 28 April 2009

 

Rainfall:

Bands of heavier rainfall occurred in the southeastern Greater Everglades (see Raindar image and below).  Basin totals last week ranged from 0.06” in WCA-2A to 1.00” in WCA-1:

 

Rain:                            WCA-1:         1.00 in            WCA-3A:          0.05 in

                                    WCA-2A:       0.06 in            WCA-3B:          0.38 in

                                    WCA-2B:       0.15 in             ENP:                 0.16 in

 

Water Conservation Areas:

The high rate of pan evaporation (1.80 in, see srs pdf) continues to draw down water levels, which are declining at rates considered Fair or Good for wading birds throughout the WCAs (see WCA Stages spreadsheet), but were particularly high in WCA-2A and -3A, -0.30 and -0.28 ft, respectively, last week.  WCA-2A is dry (see attached WCA2A photo)

 

Stage Change:             WCA-1:          -0.17 ft             WCA-3A:        - 0.28 ft

                                    WCA-2A:       -0.30 ft             WCA-3B:         - 0.15 ft

                                    WCA-2B:       -0.18 ft              NESRS:           - 0.03 ft

 

All WCAs remain far below their regulation schedules.  The WCA-1 marsh is about -0.5 ft below, WCA-2A canal stage has dropped to about -1.4 ft below, and the WCA-3A marsh is about -0.5 ft below Zone E1 (see Reg schedule).

 

Twenty gauges in Big Cypress, the WCAs, and in ENP have bottomed out (so recorded water levels are incorrect).  Gauges that are recording correctly have been used to produce this week’s maps, but until water levels rise, map areas representing Big Cypress are probably incorrect.

 

Water depths are below ground in much of the Greater Everglades (see attached map).  Except for coastal areas, Everglades National Park is dry, with soil water depths well below -1 ft in most of the Park.  Water depths -1 ft or below exist in WCA-2A and the northern half of WCA-3A.  Surface water remains only in parts of WCA-1, WCA-2B, southern WCA-3A, and WCA-3B.  

 

The driest areas of the WCAs are now in the High risk category for muck fires (see muck fire risk map), and most of the Greater Everglades at Moderate risk.  The wetter sections of WCA-1, WCA-2A, and WCA-3A and -3B, and coastal ENP are still in the Low muck fire risk category.

 

Wading bird feeding conditions remain good in parts of WCA-1, -3A, and -3B (see Recession Rates map).  The rest of the Greater Everglades are too dry, with a few areas still too deep for feeding.  With continuing high evaporation rates, these areas will continue to provide for future foraging for a while.

 

Everglades National Park (ENP) and Florida Bay:

Light rain fell across ENP and Florida Bay last week, with moderate to heavy rain across coastal Dade County to the east.  ENP measured 0” – 0.5”, and the basin-wide spatially-averaged weekly RAINDAR totals were 0.03” and 0.19” for the ENP and C-111 basins, respectively (image attached).

 

Stages continued to drop last week (see Stages pdf).  Water levels in Shark River Slough and at the Taylor Slough Bridge dropped by 2.5” and 3.6”, respectively.  To the south, water levels in the ENP panhandle and at Craighead Pond dropped by 2.2” and 2.9”, respectively.  NOTE: Water level is now below the wetland surface at all of these four monitoring stations.

 

Salinity (see Salinity pdf) was mostly steady or increasing in Florida Bay last week.  Salinity increased slightly to near 39 psu in Long Sound, at the Little Madeira Bay platform, and farther into the Bay at Duck Key.  The 30 day moving average salinity at the Taylor River platform used for tracking the Florida Bay MFL increased from 30.2 psu (4/20) to 33.5 psu (4/26), with a daily mean salinity of 37.1 psu as of April 26.  In the north central Bay, salinity increased from 40 to 47 psu mid-week before dropping back to the low to mid-40s by the end of the week in Terrapin Bay and McCormick Creek.  At the central Bay platform in Whipray Basin, salinity remained in the middle 40s.  To the west, in the upstream reaches of Shark River Slough, salinity was steady at 18 psu.

 

Please contact Kevin Cunniff (kcunniff@sfwmd.gov) for questions about ENP and Florida Bay.

 

Fires:

The “Deep Fire” in Big Cypress, near Corkscrew Watershed, has urned over 24,000 acres of land, with its cause attributed to a lightning strike (see Fire Map). No fires have been reported in the WCAs or the Park for the week. 

 

Wildlife:

Large mixed flocks were observed feeding in western WCA 1 in close proximity to Colony 99 (see flocks map).  A decrease in large flocks was observed in eastern WCA 1 from several weeks prior.  We have been monitoring the effect of predation on the southwest portion of New Colony 4, and documented nest failures (at least 1000) of entire tree islands due to alligators and raccoons.  A video distributed last week shows what may be the first documented evidence of alligator predation on an ibis nest. 

 

Please contact James Beerens (jbeerens@sfwmd.gov) with questions.

 

 

 


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