M E M O R A N D U M
TO: Chip
Merriam, Deputy Executive Director, Water Resources
FROM: SFWMD
Staff Environmental Advisory Team
DATE: May 27, 2008
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No
Lake Okeechobee regulatory releases to
the south or estuaries are recommended.
Background
Mainly
dry for the next couple of days before rains increase south the end of the
week. Deep layered high pressure will
dominate the skies over the peninsula for most of the business week. Decent moisture will return south of the
Over the last
seven days, the upper Kissimmee Basin received 0.03 inches of rainfall, and the
lower basin received 0.04 inches inches (Daily
Rainfall Report 5/12/08).
During the last
week, releases from the upper basin lakes were adjusted to allow water levels
to decline with the regulation schedules. Releases from East Lake Tohopekaliga (S-59) decreased to 176 cfs.
No other released are being made
currently in the upper basin as lake stages approximate their respective
regulation schedules.
Releases from
In the upper basin, snail
kites continue to nest on East Lake Toho,
Flow has been
reestablished to the
With the
decreased inflow from the upper basin, water levels continue to decline across
the Kissimmee River Restoration Project.
The headwater stage at S-65C has decreased to 33.61 feet. Dissolved
oxygen concentrations in the river channel of the
According to the USACE web site,
Monthly phytoplankton monitoring
was performed on May 22. Six of nine
sites had sufficient water for sampling. Mean secchi depth
was 0.28 m (compared to 0.45 m in April). Chlorophyll data are not yet available, but
bloom conditions were not observed at any of the stations.
All 5 wildfires burning in
the lake’s littoral zone are nearly or fully contained and only one at Lakeport
near Fisheating Creek is expanding. Conditions were improved by rainfall in this area
over the last several days. Approximately 26,000 acres have burned.
St. Lucie Estuary
There were no releases
through S-80 from C-44 and S-48 from C-23 over the past week. The flow values from S-49 from C-24 were
unavailable. 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 |
|
18.89 (19.24) |
20.14 (20.81) |
|
HR1 (N. Fork) |
21.67 (20.62) |
22.90 (22.85) |
|
|
NR (22.95) |
NR (24.22) |
8.0 – 25.0 |
A1A Bridge |
29.49 (30.30) |
30.42 (31.83) |
20.0 – 31.0 |
Average salinity increased
slightly at HR1 and decreased slightly at
Caloosahatchee Estuary
No discharge occurred through
S-79 during the past week. An average
weekly discharge of 274 cfs occurred at S-77and 131 cfs at S-78. The concentration of chlorides at the Olga
Plant was 248 ppm yesterday, up from 237 ppm in the beginning of this reporting period. Current weekly averages (in bold) may be
compared to last week’s data (in parenthesis).
|
Weekly Average Salinity
(ppt) |
|
Sampling Site |
Surface |
Bottom |
|
16.71 ( 16.74) |
17.47 (17.25) |
Rt. 31 Bridge |
18.12 (17.67) |
19.06 (18.67) |
I-75 Bridge |
19.44 ( 18.64 ) |
20.51 (20.08) |
|
24.53 (24.41) |
24.77 (24.56) |
|
31.89 (31.47) |
32.51 (32.13) |
Shell Point |
35.86 (35.67) |
36.51 (36.38) |
Average salinities increased
slightly (< 1 ppt) throughout the estuary. Average salinity at the
FWRI reports that no Karenia
brevis, the
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. Stages increased
throughout the WCA’s, but continue to decline in Everglades
National Park (ENP). Stages are slightly above regulation in WCA-1, well above Regulation in WCA-2A
and slightly below regulation in WCA-3A.
Rainfall was patchy across ENP and Florida Bay last week, with the 7 day 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.
Modest rainfall buffered the
persistent strong southerly winds and high rates of evaporation last week,
allowing salinity in much of
Water Supply
Although there was some
scattered rain last week, most water levels decreased across most of the District. Water levels in the upper and lower
There was no change in the
water supply risk indicators since last week.
Six out of 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