MEMORANDUM
TO: Chip
Merriam, Deputy Executive Director, Water Resources
FROM: SFWMD Staff Environmental Advisory Team
DATE: December 4, 2007
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No Lake Okeechobee regulatory releases to the
south or estuaries are recommended.
Background
A few showers south this
morning, then cooler. A cold front across the southern end of the District will
push into the Keys later today and then stall over the Florida Straits tonight.
Some light rain and showers will affect the southern tip of the District today
and then cooler temperatures and dry conditions will spread over the area
behind the front tonight through Thursday. As the old frontal boundary lifts
back north ahead of the next frontal system, some spotty showers will return
south Thursday night and then scattered showers mainly east Friday and
Saturday. The next ten days precipitation outlook is below average with low confidence.
Over the last 7
days, the upper
Water levels in
Lakes Kissimmee, Hatchineha and
According to the USACE web site,
During November, 22 of the
27 water quality sampling sites had sufficient water for sampling. Lakewide, TP averaged 127 ppb and TSS
averaged 41 mg/L. These concentrations
are similar to those measured in October. Average TP at nearshore sites increased from 52 ppb in October to 80 ppb
in November and TSS increased from 10 mg/L to 19
mg/L. Monthly phytoplankton monitoring was performed last week and no algal
blooms were observed.
St. Lucie Estuary
There were no releases
through S-80 over the past week. Discharge
at S-97 on the C-24 Canal averaged 0 cfs. Discharge at S-49 on the C-23 canal averaged
23.5 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 |
|
7.6
(7.2) |
9.1
(8.6) |
|
HR1 (N. Fork) |
9.5
(9.0) |
12.8 (10.9) |
|
|
13.3 (12.8) |
13.7 (12.9) |
8.0 – 25.0 |
A1A Bridge |
21.4 (22.3) |
26.4 (26.6) |
20.0 – 31.0 |
Salinity increased this
week upstream of the
Caloosahatchee Estuary
No discharge occurred at
S-79 last week. The concentration of
chlorides at the Olga Plant is 128 mg/l. Average salinity increased throughout the
estuary last week except at S-79. 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 |
|
13.6 (14.7) |
14.4 (15.0) |
Rt. 31 Bridge |
13.8 (13.5) |
16.1 (14.9) |
I-75 Bridge |
14.0 (13.4) |
17.0 (15.7) |
|
19.1 (19.0) |
20.2 (19.2) |
|
24.0 (23.7) |
27.2 (26.8) |
Shell Point |
32.5 (32.4) |
34.1 (33.9) |
Salinity conditions
throughout the system remain good seaward of
FWRI reports that background concentrations of Karenia brevis, the
Water Conservation Areas
Dry season
recession predominates in most regions but the rate of decline was generally
slightly less that of last week. The
exception was NW WCA 3-A where water levels increased
slightly, probably due to the rainfall event. Water depths decreased by 0.04’ in WCA-1, 0.11’ in WCA-2A, 0.05’ in WCA-3A, 0.09’ NESRS, and by 0.04’
in WCA-3B. Water
depths are typically above 2 ft, at this time of year, in the WCAs. However, on
average, all the WCAs (except WCA-2B)
have water depths below 2.0 ft. Stages in WCA-1 are
in Zone B, WCA-2A remains well above regulation, and
stages in WCA-3 remain below regulation.
Trends for ENP wetland water levels were mixed for the week. The water level has remained remarkably
constant in Shark River Slough (@ P33), holding near 1.3’ above ground surface
for yet another week (although still low for this time of year). In the southern part of the system, water
level declined by 0.6” at Craighead Pond and by 1.2” in the panhandle at EVER6 over the week.
Salinity either decreased
slightly or remained stable across
Water Supply
Water
levels in the upper and lower
The
Water Supply Risk Measures were unchanged this week. Six 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 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.
The
CPC Precipitation Outlook and Multi-Seasonal Net Inflow Forecasts remain at
“medium” risk this week.
WSE
(
The current
CC: George
Horne