MEMORANDUM
TO: Chip
Merriam, Deputy Executive Director, Water Resources
FROM: SFWMD Staff Environmental Advisory Team
DATE: February 12, 2008
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No Lake Okeechobee regulatory releases to the
south or estuaries are recommended.
Background
Showers and thunderstorms today and Wednesday. A developing low pressure system over the
central Gulf of Mexico will move northeastward and pull an old front back north
over the District. Expect widespread
showers and thunderstorms with locally heavy rainfall amounts to move over the
District from the south and west during the day today and continuing tonight. The exiting low will push a cold front
southward through the District Wednesday bringing showers and thunderstorms
mainly over the southern half of the District Wednesday. Dry air will then settle in for Thursday
before the front returns north again and brings showers east. The next
ten days precipitation outlook is above average with moderate confidence.
Over the last 7 days, the upper
Snail
kites have begun nesting in the upper basin.
Aerial
surveys were conducted last month (January 10) for water birds on the
According
to the USACE web site,
In
January, 20 of the 27 water quality sampling sites had sufficient water for
sampling. Preliminary lake wide TP averaged 232 ppb and TSS
averaged 104 mg/L. These concentrations
are higher than those measured in December (TP = 97
ppb, TSS = 21 mg/L).
Preliminary average TP at near shore sites
increased from 54 ppb in December to 117 ppb in January and TSS
increased from 10.5 mg/L to 35.8 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 8 of the 29
sites sampled. This distribution is
lower than that reported in December, with slight reductions in the density of Chara. Water clarity decreased with secchi depths less than 50% of total depths at 10 of the 29
sites sampled. One species of vascular SAV, Vallisneria
St. Lucie Estuary
There
were no releases through S-80 over the past week. No discharge occurred at S-97 on the C-23
Canal or at S-49 on the C-24 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 |
|
12.9 (11.8) |
15.6 (15.5) |
|
HR1 (N. Fork) |
16.4 (16.5) |
18.7 (19.0) |
|
|
22.0 (19.5) |
22.5 (20.5) |
8.0 – 25.0 |
A1A Bridge |
28.0 (25.7) |
28.9 (27.3) |
20.0 – 31.0 |
Average
salinity increased during the past week at most sites. Both the surface and bottom salinity are in
the preferred range at the
Caloosahatchee Estuary
No
discharge occurred at S-79 last week.
The concentration of chlorides at the Olga Plant is 175 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 |
|
17.6 (17.0) |
17.7 (17.6) |
Rt.
31 Bridge |
18.1 (17.3) |
19.8 (20.1) |
I-75
Bridge |
NA (NA) |
21.2 (21.1) |
|
23.9 (24.0) |
23.8 (24.2) |
|
27.1 (26.2) |
30.8 (30.8) |
Shell
Point |
34.3 (34.5) |
35.4 (35.9) |
Salinity
at the
FWRI reports that no Karenia brevis, the
Water Conservation Areas
Good dry-season recession rates dominate
the entire region. Water
depths for water bird foraging is good in WCA-2A,
northern WCA-3A and Shark River Slough. Stages in WCA-1 remain slightly below Regulation, WCA-2A
remains above regulation, and WCA-3 stages continue
to be significantly below regulation
Everglades
National Park (ENP) wetland water levels continued to
drop in response to low precipitation. Water
level at
Salinity
concentrations remained stable or increased slightly in
Water Supply
Water
levels in the upper and lower
Six
out of eleven water supply risk measures are in the “high” risk category
including the projected Lake Okeechobee Stage (SSM),
the Palmer Index for Tributary Conditions, the CPC Precipitation Outlook, and
Lower East Coast Service Areas 1, 2 and 3.
One
change from last week is the LOK Seasonal Net Inflow
changed from high to medium risk. The LOK Multi-Seasonal Net Inflow Forecasts remains at “medium”
risk this week. Water Conservation Areas
1 and 2A continue to be in the “low” risk category and Water Conservation Area
3A remains at “medium” risk.
Chlorides
at the Olga WTP on the
WSE
(
The
current
CC: George
Horne