MEMORANDUM
TO: Chip Merriam, Deputy Executive
Director, Water Resources
FROM: SFWMD
Staff Environmental Advisory Team
DATE: May 6, 2008
SUBJECT: Weekly Environmental
Recommendation for Systems Operations
Recommendation
No Lake Okeechobee regulatory releases to the south or
estuaries are recommended.
Background
Warm and mostly dry. High pressure is building over the area and
will bring dry conditions today and Wednesday.
A cold front is forecast to push into north
Over the last seven days, the upper Kissimmee Basin received 0.10
inches of rainfall to bring the 30 day total to 2.81 inches (113% of average),
and the lower basin received 0.02 inches to bring the 30 day total to 2.74
inches (115% of average).
During the last week, releases were either increased or initiated
for several of the upper basin lakes. Releases from
The
vegetation removal project on
Hydrilla treatment continues in
Flow has been reestablished to the
A
recommendation was made on Friday (May 2, 2008) to begin lowering the water
levels (headwater stage) at S-65C from the current elevation of 35 feet to 33 feet
by June 1 for environmental purposes. Healthy wetland plant communities require
fluctuating water levels and periodic drying. Since Phase I of the Kissimmee River
Restoration Project was completed in 2001, water levels have been varied to
improve conditions at the lower end of Pool C that ordinarily would experience
stabilized water levels. The water
levels have not decreased to 33 feet since 2003, and there are indications of
problems, especially with mat-forming species. Current conditions of moderate inflow at S-65
and low rainfall will favor lowering water levels.
According
to the USACE web site,
An
apple snail egg survey was initiated along the northwestern and western littoral
zones and in
Bloom
sites that were reported on last week (Pahokee Marina and LZ40
in the center of the lake) were sampled again at the end of last week. Chlorophyll and toxin data are not yet
available, but the blooms at both sites have largely dissipated.
A
wildfire continues to burn in the littoral zone near
St. Lucie Estuary
There
were no releases through S-80 from C-44, S-49 from C-24, and S-48 from C-23
over the past week. The current weekly
average salinities (in bold) at the four monitoring sites in the St. Lucie are
given below in parts per thousand (ppt), along with
the previous week’s (in parenthesis).
|
Weekly Average Salinity (ppt) |
|
|
Sampling Site |
Surface |
Bottom |
Envelope |
|
15.16 (13.98) |
16.13 (15.26) |
|
HR1 (N. Fork) |
16.88 (17.57) |
18.14 (18.77) |
|
|
16.07 (16.76) |
18.81 (18.95) |
8.0
– 25.0 |
A1A Bridge |
26.56 (27.28) |
30.07 (29.16) |
20.0
– 31.0 |
Average
salinity increased about 1 ppt in the South Fork and
North Fork, and remained about the same at
Caloosahatchee Estuary
The
flow data at the structures along C-43 were available for only three days
during the last week. There was no flow
through S-79 at the beginning of the reporting period and the gates were closed
Monday May 6th. As of May 2nd,
the prior 30-day average flow from S-79 was 130 cfs. During the beginning of the week, flows at
S-77 from
|
Weekly Average Salinity (ppt) |
|
Sampling Site |
Surface |
Bottom |
|
15.74 ( 13.77) |
16.45 (14.64) |
Rt.
31 Bridge |
15.77 (13.33) |
17.68 (NA) |
I-75
Bridge |
16.47 ( NA ) |
18.68 (17.41) |
|
22.29 (21.36) |
23.16 (22.23) |
|
29.36 (28.35) |
29.51 (28.98) |
Shell
Point |
34.55 (34.50) |
35.36 (35.22) |
Average
salinities increased approximately 2 ppt in the upper
estuary, about 1 ppt in the lower estuary at
FWRI reports that no Karenia
brevis, the
Water Conservation Areas
Recession rates were excellent in almost all the WCA’s. Only NE Shark
River Slough and WCA-3B had rainfall quantities
sufficient to cause slight reversals. However, large regions of the WCA’s continue to exhibit depths greater than 1 foot. Depths greater than one foot are inhospitable
for wading bird foraging. Stages in WCA-1 have declined and are at Regulation, WCA-2A marsh remains well above regulation and WCA-3A stages are within zone E1 of the regulation schedule
for protection of the Cape Sable Seaside Sparrow.
Patterns
for Everglades National Park (ENP) wetland water
levels followed those for rainfall (areas that saw rain were up, while other
areas without precipitation declined). Nearly
1.5” of rainfall in Shark River Slough (station P33) allowed water levels here
to increase for the week by 1.3”. Fueled
by low rain & high evapotranspiration, water
level was down for a second week by nearly 5” over the 7 day period at Taylor
Slough. Bridge (not an unusual recession rate at this station). The southern part of Taylor Slough (at Craighead
Pond) also posted declining water levels, down by 1.7” for the 7 day period.
Salinity
in
Wildlife
The
monthly colony survey revealed that the recent improvements in hydrologic
conditions have not initiated a late surge in nesting activity. A total of 1195 nests (795 egrets and 400
White Ibis nests) were counted. This is
almost double last month’s count but considerably lower than both the May 2006
and May 2007 counts when 36625 and 7170 nests were observed, respectively. Most nesting activity is in the Refuge.
Most
areas of the WCAs supported low numbers of foraging
birds. Very few birds were seen in WCA-3A or WCA-2A and most activity was seen in the northern Refuge
Water Supply
Last
week was relatively dry, so most water levels decreased slightly across the District. Water levels in the upper and lower
Six
out the eleven water supply risk indicator parameters are now in the “low” risk
category, including the CPC Precipitation Outlook, the Lake Okeechobee Seasonal
and Multi-seasonal Net Inflow Forecast, and Water Conservation Areas 1, 2A and
3A.
Four
out the eleven water supply risk indicators are now in the “medium” risk
category, including the Palmer Index for Tributary Conditions (dry) and the LEC Service Areas 1, 2 and 3.
The
only risk measure that is in the “high” risk category is the projected Lake
Okeechobee Stage (water restriction zone).
LORS2008 (
The
current
CC: George Horne