MEMORANDUM
TO: Chip
Merriam, Deputy Executive Director, Water Resources
FROM: SFWMD Staff Environmental Advisory Team
DATE: January 15, 2008
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No Lake Okeechobee regulatory releases to the
south or estuaries are recommended.
Background
Some
showers by the end of the week. Cooler
and dry conditions will move over the area as a cold front clears the south end
of the peninsula today. The first in a
series of upper level impulses will move across north
Over the last 7 days, the upper
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
According
to the USACE web site,
In
December, 24 of the 27 water quality sampling sites had sufficient water for
sampling. Preliminary lake-wide, TP averaged 97 ppb and TSS
averaged 21 mg/L. These concentrations
are lower than those measured in November.
Preliminary average TP at near shore sites
decreased from 80 ppb in November to 54 ppb in December and TSS
decreased 19 mg/L to 10.5 mg/L.
The
monthly submerged-aquatic-vegetation (SAV) survey was
completed last week. The macroalga Chara remains
the dominant SAV species and was found at 12 of the
24 sites sampled. This distribution is
lower than that reported in November, with slight reductions in the density of Chara despite continued good to excellent
water clarity (secchi depths 50-100% of total
depths). One species of vascular SAV, Vallisneria
St. Lucie Estuary
There
were no releases through S-80 over the past week. Discharge at S-97 on the C-24 Canal and at
S-49 on the C-23 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 |
|
9.4 (9.3) |
12.3 (11.2) |
|
HR1 (N. Fork) |
13.2 (13.3) |
15.5 (15.7) |
|
|
16.6 (16.5) |
16.7 (17.1) |
8.0 – 25.0 |
A1A Bridge |
24.2 (24.5) |
26.7 (27.3) |
20.0 – 31.0 |
Average
salinity changed only slightly during the past week. Both the surface and bottom salinity are in
the preferred range at the
FWRI reports that in Indian River and St. Lucie counties,
samples collected within the Indian River Lagoon contained concentrations of Karenia brevis, the
Florida red tide organism, ranging from not present to very low.
Caloosahatchee Estuary
No
discharge occurred at S-79 last week.
The concentration of chlorides at the Olga Plant is 167 mg/l. Average salinity increased 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 |
|
18.7 (14.8) |
18.7 (15.5) |
Rt.
31 Bridge |
17.4 (14.4) |
19.1 (15.5) |
I-75
Bridge |
NA (14.6) |
21.8 (18.3) |
|
23.0 (20.1) |
24.0 (21.0) |
|
25.7 (26.9) |
29.0 (27.9) |
Shell
Point |
33.7 (NA) |
35.5 (NA) |
Conditions
in the upper estuary are poor due to high salinity. The current salinity of
18.7 ppt at S-79 is 2.6 ppt
below the maximum weekly average of 21.0 ppt recorded
in May 2001. Salinity at the
FWRI reports that water samples collected alongshore this week between
Pinellas and Monroe counties contained no Karenia
brevis, the
Water Conservation Areas
Overall good dry-season recession rates
continue to dominate the region.
Northern and central WCA-3B continues to have
fair recession rates due to little change over time. Although recession rates were good, the
depths in the
Everglades
National Park (ENP) wetland water levels continue to
decline.
Salinity
concentrations either remained stable or increased slightly 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 Multi-Seasonal Net Inflow Forecast remains
at “medium” risk this week.
Chlorides
at the Olga WTP on the
WSE
(
The current
CC: George
Horne