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: July
22, 2008
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No
Lake Okeechobee regulatory releases to
the south or estuaries are recommended.
Background
Increased showers/storms today and tomorrow.
The last few days have seen well below average rains as tropical systems
that developed around us spewed exhaust fumes over the peninsula. These negative influences on our rains should
begin to wane today. Morning soundings
show more moisture, cooler mid levels, and more favorable upper level winds for
the seabreeze to work with. Light steering winds make it more difficult
to find a focus; but, areas north through east of of Lake Okeechobee (
Over the last seven days, the
upper Kissimmee Basin received 2.06 inches of rainfall to bring the 30 day
total to 7.80 inches (113% of average), and the lower basin received 2.39
inches to bring the 30 day total to 10.07 inches (156% of average).
Water levels are rising in
all of the upper basin lakes including
In the upper basin, snail
kites continue to nest on East Lake Toho,
Flow is approximately 200 cfs at S65 and 1800 cfs at S65C.
Water levels within the
Kissimmee River Restoration Project area have been rising and falling in
response to rainfall events. The water
level (headwater stage) at S-65C has been allowed to rise to 34 feet.
From 7/15/08 to 7/21/08
dissolved oxygen concentrations in the
According to the USACE web
site,
Monthly phytoplankton
monitoring was performed on July 17. Six
of nine sites had sufficient water for sampling. Mean secchi depth
was 0.59 m (compared to 0.43 m in June).
Chlorophyll and toxin data are not yet available, but bloom conditions
were not observed at any of the stations.
The South American watergrass Luziola subintegra continues to pose an environmental threat in
St. Lucie Estuary
There were no releases
through S-80 from C-44 over the past week.
An average discharge of 121 cfs through S-48 from C-23 and 448 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 |
|
6.48 (4.40)
|
7.46
(4.91) |
|
HR1 (N. Fork) |
2.58 (2.39) |
9.51 (5.24) |
|
|
8.38 (7.24) |
11.40 (8.79) |
8.0 – 25.0 |
A1A Bridge |
16.95
(15.00) |
24.26
(21.68) |
20.0 – 31.0 |
Compared with salinities of
the previous week, average salinity in the estuary increased about 0.2 to 4.3 ppt. Salinity
conditions in the estuary are considered to be fair, based on the salinity
preference of the oyster, Crassostrea virginica.
Caloosahatchee Estuary
An average weekly discharge
of 2540 cfs occurred
at S-79. The concentration of chlorides
at the Olga Plant was 54 ppm yesterday, down from 81 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).
|
Weekly Average Salinity
(ppt) |
|
Sampling Site |
Surface |
Bottom |
|
0.43 (3.60) |
0.40
(3.84) |
Rt. 31 Bridge |
NR (NR) |
NR (NR) |
I-75 Bridge |
0.85
(4.14) |
1.10
(8.98) |
|
3.15
(10.24) |
3.55
(15.06) |
|
10.06
(18.36) |
10.43
(20.30) |
Shell Point |
20.84
(28.76) |
22.57
(29.47) |
Compared with salinities of
the previous week, average salinity decreased throughout the estuary due to
local runoff. Average salinities dropped
between 3 ppt and 11 ppt
depending on location and depth. Salinity conditions in the upper
estuary east of
No Karenia brevis, the
Water Conservation
Areas
The wading bird
foraging period ended everywhere in the EPA 2-3 weeks ago because all areas had
significant stage increases and all are too deep for wading bird foraging. This week, evapotranspiration
was relatively low, but so was precipitation and therefore there were regions
of the
Stages are currently
above regulation in all three Water Conservation Areas.
Stages were up across much of
the Everglades National Park (ENP) wetlands, but by varying amounts depending
on local rainfall. Water level in the
panhandle (station EVER6) remained nearly unchanged for the week. Shark River Slough (station P33) saw
increasing water level (up by 0.6”) last week. Water levels were also up in Taylor Slough:
Salinity trends across
Wildlife:
Last week U.S. Fish and
Wildlife biologists have found nests and recently hatched birds of the
endangered Everglade snail kite in a small wetland in the Loxahatchee National
Wildlife Refuge. An analysis is ongoing to look at WCA use by snail kites and
will be reported as part of the District’s Annual Wading Bird Report.
For the last few weeks a bear
(or two) appears to be ripping down scientific instruments on tree islands in
the central
Water Supply
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