MEMORANDUM
TO: Chip Merriam, Deputy Executive Director,
Water Resources
FROM: SFWMD Staff
Environmental Advisory Team
DATE: September
25, 2007
SUBJECT: Weekly Environmental Recommendation
for Systems Operations
Recommendation
No
regulatory releases
to the south or estuaries are recommended.
Background
Showers and
thunderstorms; heaviest east. A low has spun up
in the upper level trough currently lying east-west across the District. This upper low is producing very favorable
upper level winds over the southern half of the District which should tap ample
moisture and allow shower and thunderstorms to redevelop near the south and
east coasts and move northwest and west today and tonight. As the upper low shifts slowly westward,
expect a similar pattern Wednesday and Thursday with activity spreading more
northward each day. As the upper low
weakens, daily shower activity should drop down a bit Friday before increasing
again Saturday and Sunday as a cold front moves into north Florida and interacts
with tropical moisture.. The next
ten days precipitation outlook is near average with low confidence.
The upper Kissimmee Basin received 2.18
inches of rainfall over the last 7 days to bring the September total to 4.31
inches (88% of average) and the lower basin received 1.64 inches to bring the
September total to 5.38 inches (112% of average) (Daily Rainfall Report for
09/25/07).
Stages in most of the upper basin lakes have been
stable over the last seven days.
Snail kites continue to nest on
Flow has been reestablished to the
According to the USACE
web site,
Monthly algal bloom monitoring was conducted at 5
sites on the 12th of September. Chlorophyll concentrations were well below
bloom levels (defined as concentrations ≥40 ppb) at 4 sites and just at
bloom levels (39 ppb) at one site near the Clewiston water intake. Algal toxin data for this month have not been
reported. Total phosphorus
concentrations averaged 99 ppb, with highest concentrations (213 ppb) at the
mouth of the
St. Lucie Estuary
Release information from S-80 was unavailable the
past week. Weekly average salinities at
the four monitoring sites in the St. Lucie are given below in parts per
thousand (ppt).
|
Weekly Average Salinity (ppt) |
|
|
Sampling Site |
Surface |
Bottom |
Envelope |
|
6.50 |
7.64 |
|
HR1 (N. Fork) |
6.31 |
10.54 |
|
|
11.37 |
11.87 |
8.0 – 25.0 |
A1A Bridge |
18.37 |
24.10 |
20.0 – 31.0 |
Salinity declined slightly throughout the
estuary. Both the
Caloosahatchee Estuary
During the past week, discharge at S-79 averaged
342.57 cfs.
Chloride concentration at the Olga Plant is presently 75 mg/l.
Average salinity at all monitoring sites in the Caloosahatchee Estuary decreased
slightly over the past week due to local runoff. Data for specific sites are given below in
parts per thousand (ppt).
|
Weekly Average Salinity (ppt) |
|
Sampling Site |
Surface |
Bottom |
|
5.66 |
5.66 |
Rt. 31 Bridge |
5.73 |
6.10 |
I-75 Bridge |
5.27 |
7.47 |
|
10.06 |
NA |
|
17.76 |
18.88 |
Shell Point |
27.23 |
30.06 |
Salinity in the upper estuary remains high for this
time of year. The 30-day average surface
salinity at
FWRI reports that no Karenia brevis, the
Water Conservation Areas
The declining water levels of last week have been compensated for
by the increasing water levels of this week.
Water levels increased more in the northern Everglades (WCA1 was up 0.36 ft and WCA2A was
up 0.44 ft) than they did in the southern
Rainfall was patchy across Everglades National Park (ENP)
and
Salinity showed mixed trends across FL Bay last week. Strong southerly winds from last week’s low
pressure system caused flow reversals that increased salinity for much of the
latter part of the week in areas of northern
Water Supply
Water levels in the upper and lower
Six out of eleven water supply risk measures are in
the “high” risk category this week – no change from last week - including the
projected Lake O Stage (SSM), the Palm Index for
Tributary Conditions, the LOK Multi-Seasonal Net
Inflow Forecast and Lower East Coast Service Areas 1, 2 and 3.
Water Conservation Areas 1 and 2A continue to be in
the “low” risk category and Water Conservation Area 3A is now at “medium”
risk. The CPC Precipitation Outlook
remains at “low” risk this week, and the LOK Seasonal
Net Inflow forecast is now at “medium” risk.
WSE
(
The
current
CC: George Horne