MEMORANDUM
TO: Chip
Merriam, Deputy Executive Director, Water Resources
FROM: SFWMD Staff Environmental Advisory Team
DATE: January 8, 2008
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No Lake Okeechobee regulatory releases to the
south or estuaries are recommended.
Background
Dry and warm through Thursday
before some showers return for the weekend.
High pressure will dominate through Thursday, leaving dry and pleasant
conditions. Change begins on Friday when
a cold front moves down into the panhandle of
Over the last 7 days, the upper
According
to the USACE web site,
Phytoplankton
bloom monitoring was conducted on December 26th. Six out of 9 monitoring stations had
sufficient water for sampling. No algal
blooms were observed with the exception of light bloom formation at the Pahokee
Marina. No algal toxins were
detected. Chlorophyll and total P data
from this trip are not yet available.
Monthly
SAV monitoring is being conducted this week. Slight reductions in the density of the macroalga Chara were
reported at the south end of the lake on Monday despite continued good to
excellent water clarity (secchi depths 50-100% of
total depths). No vascular SAV species were encountered.
St. Lucie Estuary
There
were no releases through S-80 over the past week. Discharge at S-97 on the C-24 Canal averaged
0.5 cfs. There
was negligible discharge at S-49 on the C-23 canal. 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 |
|
9.3 (6.7) |
11.2 (9.9) |
|
HR1 (N. Fork) |
13.3 (11.4) |
15.7 (14.3) |
|
|
16.5 (14.2) |
17.1 (16.1) |
8.0 – 25.0 |
A1A Bridge |
24.5 (23.1) |
27.3 (27.0) |
20.0 – 31.0 |
Salinity
increased this week at all monitoring sites.
Both the surface and bottom salinity are in the preferred range at the
FWRI reports that along the East Coast, background
concentrations of the red tide organism, Karenia
brevis, were detected at
Caloosahatchee Estuary
No
discharge occurred at S-79 last week.
The concentration of chlorides at the Olga Plant is 178 mg/l. Average salinity increased in the upper
estuary changed only slightly over the past couple of weeks. Shell Point was not reporting. 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 |
|
14.8 (13.6) |
15.5 (14.7) |
Rt.
31 Bridge |
14.4 (13.8) |
15.5 (17.4) |
I-75
Bridge |
14.6 (14.5) |
18.3 (19.8) |
|
20.1 (21.4) |
21.0 (21.9) |
|
26.9 (25.4) |
27.9 (28.5) |
Shell
Point |
NA (32.5) |
NA (34.1) |
Conditions
are poor in the upper estuary due to high salinity. 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
Good dry-season recession rates (averaged
over the last three weeks) continue to dominate the region. WCA-3B was the only
area where recession rates were Fair due to little
change over time. Although recession rates were Good,
the depths in the
This is normally not an issue at this time
of year because foraging in support of nesting behavior does not usually begin
until February. Only the NW corner of WCA-3A had proper depths and recession rates to support
wading birds. However; birds are not
using this area. It may be that fish prey are not available (NOTE: Last year’s drought caused an
80% reduction in food, compared to the previous high-nesting-success year, for
wading birds across the system). Stages
in WCA-1 are slightly below at Regulation, WCA-3 stages continue to be significantly below regulation,
and WCA-2A remains above regulation.
Light
rainfall over the holidays allowed Everglades National Park (ENP) wetland water levels to continue to decline. In general, stations in the northern part of
the system saw more substantial declines than those to the south. Not surprisingly recession has been most
dramatic at
Several
of the marine monitoring stations have not transmitted data over the past
week. Overall, though, using what data
are available (through USGS platforms & a few ENP stations that are online) it seems that FL Bay salinity
as a whole remains fairly low for this time of year. Salinity concentrations at Trout Ck. have
generally remained in the mid-20s, while concentrations at
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 Forecasts remain at “medium” risk this week.
Chlorides
at the Olga WTP on the
WSE
(
The current
CC: George
Horne