MEMORANDUM
TO: Chip
Merriam, Deputy Executive Director, Water Resources
FROM: SFWMD Staff Environmental Advisory Team
DATE: January 22, 2008
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No Lake Okeechobee regulatory releases to the
south or estuaries are recommended.
Background
Some showers mainly south today,
then interior tomorrow. Decent moisture
exists over south this morning with isolated showers. Look for these showers to increase some this
afternoon as a weak upper level impulse moves through. A rumble or two of thunder might even be
heard. Steering winds change tomorrow,
and showers should pull northward and form more over the interior. A weak cold front will push through on
Thursday with a few more showers before cooler and dry weather returns Friday
and Saturday. The next
ten days precipitation outlook is below average with low confidence.
The seven day raindar rainfall estimates
indicate about 1.5 inches of rainfall over the upper basin and 0.5 inches over
the lower basin for the time period 1/15/08 – 1/22/08. With the recent rainfall, water levels in the
upper basin lakes rose slightly, approximately 0.1 feet. Water levels in the upper basin lakes are
below regulation schedules except for
The only releases being made in the upper basin are at S-65, which
is discharging approximately 250 cfs. Flow has been reestablished to the
In the river channel of the
According
to the USACE web site,
Results
of the January monthly submerged-aquatic-vegetation (SAV)
survey showed a decrease in average SAV biomass to
0.21 g DW m-2 from 2.31 g DW m-2 in December. A normal seasonal decline in the macroalga Chara is
responsible for this pattern. The area
behind King’s Bar continues to be one of the few areas supporting a nascent
vascular SAV community. Vallisneria
continues to be found there and Hydrilla was
observed last week. This area was
relatively sheltered from the damaging effects of the 2004-2005
hurricanes. Current water levels
continue to favor the development of new areas of emergent vegetation,
including spikerush and bulrush, along the outer edge
of the marsh from Clewiston up to the mouth of the
St. Lucie Estuary
There
were no releases through S-80 over the past week. Discharge at S-97 on the C-23 Canal and at
S-49 on the C-24 canal averaged < 1.0 cfs. 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 |
|
11.1 (9.4) |
13.5 (12.3) |
|
HR1 (N. Fork) |
15.4 (13.2) |
16.8 (15.5) |
|
|
18.7 (16.6) |
17.9 (16.7) |
8.0 – 25.0 |
A1A Bridge |
27.6 (24.2) |
28.9 (26.7) |
20.0 – 31.0 |
Average
salinity increased during the past week.
Both the surface and bottom salinity are in the preferred range at the
FWRI reports that concentrations of Karenia
brevis, the
Caloosahatchee Estuary
No
discharge occurred at S-79 last week.
The concentration of chlorides at the Olga Plant is 182 mg/l. Average salinity changed little over the past
week. Weekly average salinities for
specific sites are given below in parts per thousand (ppt). Current weekly averages (in bold) may be
compared to last week’s data (in parenthesis).
|
Weekly Average Salinity (ppt) |
|
Sampling Site |
Surface |
Bottom |
|
18.5 (18.7) |
18.7 (18.7) |
Rt.
31 Bridge |
17.7 (17.4) |
18.4 (19.1) |
I-75
Bridge |
(NA) |
20.5 (21.8) |
|
22.7 (23.0) |
22.9 (24.0) |
|
25.9 (25.7) |
29.1 (29.0) |
Shell
Point |
32.8 (33.7) |
34.5 (35.5) |
Conditions
in the upper estuary east of
FWRI reports that water samples collected between
Water Conservation Areas
Good dry-season recession rates continue
to dominate the region. WCA-3B was the only area where recession rates were poor
due to little change over of the last few weeks. This should not set off any alarms and
desires to decrease WCA-3B water levels at this time
because water levels are below average for this time of year. Stages in WCA-1 are
below Regulation, WCA-3 stages continue to be
significantly below regulation, and WCA-2A remains
above regulation.
Everglades
National Park (ENP) wetland water levels continue to
decline.
Salinity
concentrations decreased slightly or remained stable in
Water Supply
Water
levels in the upper and lower
Seven
out of eleven water supply risk measures are in the “high” risk category. The projected Lake O Stage (SSM), the Palmer Index for Tributary Conditions, the CPC
Precipitation Outlook, the LOK Seasonal Net Inflow
Forecast and Lower East Coast Service Areas 1, 2 and 3.
Water
Conservation Areas 1, 2A and 3A continue to be in the “low” risk category and
the LOK Multi-Seasonal Net Inflow Forecasts remain at
“medium” risk this week.
Chlorides
at the Olga WTP on the
WSE
(
The
current
CC: George
Horne