M E M O R A N D U M
TO: Chip
Merriam, Deputy Executive Director, Water Resources
FROM: SFWMD
Staff Environmental Advisory Team
DATE: August 5, 2008
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No
Lake Okeechobee regulatory releases to
the south or estuaries are recommended.
Background
Afternoon
thunderstorm activity will continue.
Upper level wind flow has become less favorable for thunderstorm
development than it was on Monday, August 4th so expect less shower
coverage Tuesday and Wednesday with activity focused inland and west each
day. Moisture should increase from the
east Thursday and bring morning showers east and afternoon thunderstorms mainly
over the interior. A cold front is
forecast to move into
Over the last seven days, the
upper Kissimmee Basin received 1.48 inches of rainfall to bring the 30 day
total to 7.79 inches (116% of average), and the lower basin received 1.92
inches to bring the 30 day total to 8.77 inches (142% of average). Water levels continue to rise in all of the
upper basin lakes including
In the upper basin, there are
no known active snail kite nests at this time, but
there are still young being fed around nest sites on
Flow is approximately 540 cfs at S65 and 1850 cfs at
S65C. The water level in the area of the
restoration project decreases by 4.7 feet from 39.4 feet near the upstream end
of the restored reach (station KRDR02) to 34.7 feet at the downstream end
(headwater stage at S-65C). Water depths
on the floodplain within the restoration project range from approximately 0.5
to 2.4 feet.
From 7/29/08 to 8/05/08
dissolved oxygen concentrations in the
According to the USACE web
site,
S71 (1591 cfs), S72 (194 cfs), and the L8
at canal point (617 cfs), and smaller flows through
the S84 (52 cfs) and S191 (68 cfs). No outflows
are reported and flows through S77 and S308 are not available.
The Submerged Aquatic
Vegetation (SAV) south transects were completed Monday,
August 4th. Transparencies
were excellent at all sites (Secch disc visible on
bottom) and we had one reading of >bottom at a site NW of Ritta Island which was 1.6 m in depth.
Chara was still
sparse at most sites, though dense at Southbay-2. It appears as though Chara
is continuing to slowly increase in coverage and density. Unfortunately, no Val or Potamogeton was found. We also saw a nice largemouth bass in the
area of Sbay-2; no other wildlife observations of note.
St. Lucie Estuary
There were no releases
through S-80 from C-44 over the past week.
An average discharge of 250 cfs through S-48 from C-23 and 346 cfs
through S-49 from C-24 occurred over the past week. 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 |
|
5.08 (7.22) |
6.01 (8.08) |
|
HR1 (N. Fork) |
4.60 (5.31) |
9.66 (10.52) |
|
|
7.80 (9.70) |
10.32 (12.23) |
8.0 – 25.0 |
A1A Bridge |
16.63
(18.91) |
22.76
(25.61) |
20.0 – 31.0 |
Compared with salinities of
the previous week, average salinity in the estuary decreased about 0.9 to 2.9 ppt. Two of four
monitoring stations are reporting salinities within the preferred range. Salinity conditions in the estuary are
considered to be fair to good based on the salinity preference of the oyster, Crassostrea virginica, and
location in the estuary.
Caloosahatchee Estuary
An average weekly discharge
of 1195 cfs occurred
at S-79. The concentration of chlorides
at the Olga Plant was 64 ppm yesterday, up from 62 ppm in the beginning of this reporting period. The current weekly average salinities (in
bold) at the six monitoring sites in the Caloosahatchee Estuary are given below
in parts per thousand (ppt), along with the previous
week’s (in parenthesis).
Based on the USGS flow meter
located just below S77 water is flowing back into the
|
Weekly Average Salinity
(ppt) |
|
Sampling Site |
Surface |
Bottom |
|
0.29 (0.29) |
0.29
(0.29) |
Rt. 31 Bridge |
0.30 (NR) |
0.25 (NR) |
I-75 Bridge |
0.40
(0.41) |
0.39
(0.41) |
|
0.85 (1.18) |
0.86 (1.28) |
|
7.78 (6.81) |
9.54
(8.62) |
Shell Point |
22.88
(20.22) |
24.41 (22.29) |
Fresh water
extends from S-79 downstream, at least to
No Karenia brevis, the
Water Conservation
Areas
This is the time
of year that the Greater Everglades is expected to continuously rise at the
rate of some 0.1 to 0.2 ft per week.
Since rainfall was not great enough to compensate for evapotranspiration everywhere, there were regions where
stages decreased. The WCA-1 decreased
only slightly (-0.02 ft) and WCA-2A decreased significantly (-0.21 ft). Healthy re-hydration appears to be happening
in central WCA-3A and in NESRS.
Stages are at
regulation in WCA-1 and WCA-3A, but remain well above regulation in Water
Conservation Area 2A.
Spatial distribution of
precipitation was fairly even across
Salinity trends across
The issue of high salinity
across
The minimum flow to
This is something that will
need to be monitored closely.
Water Supply
There was very little change
in groundwater levels across most of the area of the District during the past
week. Water levels in the upper and
lower
There was no change in the
water supply risk indicators since last week.
Seven out of the eleven water supply risk indicator parameters are now
in the “low” risk category, including the CPC Precipitation Outlook, Palmer
Index for Tributary Conditions, the Lake Okeechobee Seasonal and Multi-seasonal
Net Inflow Forecast, and Water Conservation Areas 1, 2A and 3A.
Three out the eleven water
supply risk indicators are now in the “medium” risk category, including LEC
Service Areas 1, 2 and 3.
Only one risk measure is now
in the “high” risk category - the projected Lake Okeechobee Stage (
LORS2008 (
The current
CC: George Horne