MEMORANDUM
TO: Chip
Merriam, Deputy Executive Director, Water Resources
FROM: SFWMD Staff Environmental Advisory Team
DATE: October 30, 2007
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No
regulatory releases
to the south or estuaries are recommended.
Background
Windy with numerous showers and locally heavy rains to
4" near the east coast through tomorrow. Tropical Storm Noel has pushed inland over
eastern Cuba
and is expected to turn northwest before exiting off the north coast tonight or
early tomorrow. Regardless, the most
significant wind and rain will be east of the center and likely remain east of
the District even if the center strays closer to our coast than the official
forecast indicates. That being stated,
strong winds and numerous showers will continue to feed across mainly eastern
sections of the District with locally heavy rain near the coast through
tomorrow. As Noel exits northeast, rains
will end Thursday before dry and pleasant conditions arrive
the end of the week. The next ten days
precipitation outlook is near average with moderate confidence.
Kissimmee Watershed
Over the last 7 days, the upper Kissimmee Basin received 0.13 inches of rainfall
and the lower basin received 0.13 inches (Daily Rainfall Report for 10/29/07). For the last week, water levels have risen slightly
in most of the upper basin lakes. Four
lakes (Hart, East Tohopekaliga,
Tohopekaliga, and Gentry) are approaching the high
pool (maximum allowed) in the regulation schedule. The only releases being made in the upper
basin are at S-65.
Flow has been reestablished to the Kissimmee River for 104 days (S-65 re-opened on
07/18/07). Discharge at S-65 continues
at approximately 500 cfs. In the river channel of the Kissimmee
River, mean daily concentrations of dissolved oxygen have been
from 2 mg/L to 4 mg/L.
Lake Okeechobee
According to the USACE
web site, Lake Okeechobee stage is 10.28 NGVD, which is 0.06 higher than a week ago and 0.44
higher than a month ago. The current
stage is 2.39 lower than it was a year ago and remains almost 5 below its
historical average for this time of year.
Total reported surface inflows are 1249 cfs
and include discharges through the S65E (1154 cfs) and S191 (95 cfs) structures. This total does not include gravity flows
that might be occurring from WCA1 or through the S77
and S308 structures. No surface outflows
are reported.
The monthly submerged-aquatic-vegetation (SAV) survey was completed during the first week of October. Average SAV biomass
increased from 6.42 g dw/m2 in September to 9.1 g dw/m2 this month.
The macroalga Chara
is still the dominant species but the vascular plant Vallisneria
is still being recorded behind Kings Bar in the North and in FishEating Bay on the west side. Water clarity remains excellent at nearshore sites but is beginning to decline at offshore
sites.
St. Lucie Estuary
No releases occurred at S-80 over the past
week. The C-24 canal is discharging
about 265 cfs at S-97. Discharge at S-49 on the C-23 canal is
currently about 470 cfs. Weekly average salinities at the four
monitoring sites in the St. Lucie are given below in parts per thousand (ppt).
|
Weekly Average Salinity (ppt)
|
|
Sampling Site
|
Surface
|
Bottom
|
Envelope
|
Palm City
Bridge (S. Fork)
|
2.8
|
2.9
|
|
HR1 (N. Fork)
|
2.0
|
4.6
|
|
Roosevelt Bridge
|
5.8
|
7.0
|
8.0 25.0
|
A1A Bridge
|
16.2
|
23.0
|
20.0 31.0
|
There was little change in average salinity over
the past week. Only bottom water at the A1A Bridge fell within the preferred salinity range. Based on the salinity tolerances of the
oyster, Crassostrea virginica,
salinity conditions in the estuary are poor to fair.
Caloosahatchee Estuary
Discharge at S-79 averaged 135 cfs
over the past week. The concentration of
chlorides at the Olga Plant is 82 mg/l.
Average salinity in the estuary changed little over the past week. Data for specific sites are given below in
parts per thousand (ppt).
|
Weekly Average Salinity (ppt)
|
Sampling Site
|
Surface
|
Bottom
|
Franklin Locks (S-79)
|
7.6
|
7.7
|
Rt. 31 Bridge
|
7.3
|
8.3
|
I-75 Bridge
|
NA
|
NA
|
Ft. Myers
Yacht Basin
|
13.3
|
13.7
|
Cape
Coral Bridge
|
21.4
|
22.6
|
Shell Point
|
29.0
|
30.8
|
Salinity conditions throughout the system are good
seaward of Cape Coral. Conditions in the upper estuary are poor.
FWRI reports that offshore samples collected this week detected Karenia brevis, the
Florida red
tide organism, west of southern Lee and Collier counties. Samples collected 3
to 9 miles west and southwest of Sanibel Island (Lee County)
contained K. brevis concentrations ranging
from very low to high. Low to medium
concentrations were identified 18 miles west of both Wiggins Pass and Naples
and very low concentrations were detected 46 miles west of Naples. Additional samples collected alongshore of Sanibel Island contained K. brevis
concentrations ranging from not present to low with a single fish kill reported
from the area. All other samples
collected between Pinellas and Collier counties contained no K. brevis.
Water Conservation Areas
Water depths rose under 0.1 with the
rainfall in the Everglades except for WCA-2B, where water levels declined slightly (-0.06). The decreases that were occurring over the
last few weeks at the 2-17 and 62 gages have ceased, rising very slightly. Water depths at most gages exceed 1.25 feet,
but average conservation area depths vary a lot, ranging from 1.3 in WCA 3B to 3.4 in WCA 2B. Stages in WCA-1 are
within Zone A2, those in WCA-2A remain well above
regulation, and stages in WCA-3 now are just within
regulation.
Everglades National
Park
Rainfall was patchy but higher than the previous
week across Everglades National Park (ENP) and Florida Bay.
Wetland stations received between 0.8 - 3.4 of rainfall, and marine
stations (excluding Taylor River and Whipray Basin)
received between 0.6 - 2.5 of rainfall over the 7 day period. The spatially averaged basin-wide
accumulation for last week was 1.0.
Rainfall kept ENP wetland
water levels mostly static. The water
level at Shark River Slough (P33) decreased by 0.1 over the 7 day period and
remained low for this time of year (end of the rainy season). Southern stations depths increased by 0.6
and 0.8 at Taylor
Slough Bridge
and the ENP panhandle (EVER6),
respectively. Craighead Pond water level
was unchanged last week. All three of
these southeastern Everglades stations had
higher water levels than at this time last year.
Salinity remained low and stable across Florida Bay last week. Strong flow from the Everglades down to the
Bay through both Trout Creek and Taylor
River allowed salinity to
remain in the single digits (with a brief mid-week reversal). Salinity at the Little Madeira Bay mouth
platform remained in the low teens last week.
Salinity in the Taylor
River ponds remained
below 1 psu over the entire week. In the north-central Bay areas, Terrapin Bay and McCormick Creek salinity
decreased slightly to below 11 psu and 8 psu, respectively.
In central Florida Bay, Whipray Basin
remained below 30 psu for another week. In the Shark River Slough outflow at Tarpon Bay,
salinity remained low, dropping below 1 psu.
Water Supply
Water levels generally increased last week, with
the exception of the Lower West Coast. Water levels also rebounded in the coastal
areas of Lower East Coast over the past week,
and they are now near or slightly above their historical averages. Surface and groundwater levels in Water
Conservation Areas 1 and 2 are now near the historic averages. Water levels in WCA
3A are still somewhat below their historic averages. Water levels in the southern-most portion of Dade County
are slightly above average historic conditions as a result of local rainfall.
Six out of eleven water supply risk measures are in
the high risk category this week - the projected Lake O Stage (SSM), the Palmer Index for Tributary Conditions, 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.
The CPC Precipitation Outlook and the LOK Multi-Seasonal Net Inflow Forecast remain at medium
risk this week
WSE
(Lake Okeechobee Regulation Schedule)
The current Lake O
stage at 10.28 today - remains in the Water Shortage Management zone and is
unlikely to move back into Zone E in the next several months.
CC: George Horne