MEMORANDUM
TO: Chip Merriam, Deputy Executive Director,
Water Resources
FROM: SFWMD Staff
Environmental Advisory Team
DATE: October
16, 2007
SUBJECT: Weekly Environmental Recommendation
for Systems Operations
Recommendation
No
regulatory releases
to the south or estuaries are recommended.
Background
Mini-wet
season returns for about 5 days. Deeper
moisture just to our south and east will begin to envelop the District today as
high pressure moves into the southwest
The upper Kissimmee Basin received 0.06 inches of rainfall over
the last 7 days to bring the 30 day total to 6.25 inches (137% of average) and
the lower basin received 0.07 inches to bring the total for the last 30 days to
4.71 inches (106% of average). (Daily Rainfall Report for 10/15/07).
The
upper basin lakes are all below the regulation schedule. Stage in
According to the USACE
web site,
During September, water-quality samples were
collected from 20 of 27 sampling sites. TP concentrations lakewide
averaged 77 ppb compared to 85 ppb in August. However, TP
concentrations in nearshore areas across the southern
and western sides of the lake averaged only 33 ppb, with concentrations as low
as 11 ppb at some sites. Water clarity in nearshore
areas continues to be excellent as well.
Efforts are ongoing to assess the feasibility of
reintroducing apple snails to the lake’s littoral zone following reflooding. This
species, which is the exclusive food source for the endangered snail kite, is
especially sensitive to drought conditions and may be unable to recover quickly
by natural means. During October,
approximately 400 apple snail eggs were transported from
St. Lucie Estuary
No releases occurred at S-80 over the past week. 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 |
|
0.5 |
0.5 |
|
HR1 (N. Fork) |
NA |
0.5 |
|
|
2.81 |
3.26 |
8.0 – 25.0 |
A1A Bridge |
12.81 |
21.61 |
20.0 – 31.0 |
Average salinity increased at both the Roosevelt
and A1A Bridges last 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 53 cfs
over the past week. The concentration of
chlorides at the Olga Plant is 80 mg/l.
Average salinity increased throughout the upper estuary last week but
changed little at
|
Weekly Average Salinity (ppt) |
|
Sampling Site |
Surface |
Bottom |
|
7.5 |
7.8 |
Rt. 31 Bridge |
6.0 |
7.4 |
I-75 Bridge |
5.9 |
8.6 |
|
11.9 |
13.3 |
|
17.6 |
20.6 |
Shell Point |
26.5 |
28.5 |
Salinity conditions throughout the system are good
seaward of
FWRI reports that no Karenia brevis, the
Water Conservation Areas
The lack of rain, relative to evaporation, lead to poor rehydration rates for a second week, especially in WCA-1, where water levels declined by 0.15 ft. However, WCA-3A and
WCA 2B water levels did not recede due to release of
waters from WCA-2A.
Despite this release, water levels in WCA-2A
remained well above regulation. Water
depths remain good for this time of year because all locations have at least
1.0 ft of water. The fires that were
reported on Oct 10th along the L-67 levees in WCA-3B
did not appear to be muck burns because of these depths. Stages in WCA-1 are
no longer in Zone A2 and are now at Regulation. Stages in WCA-3
are again slightly below regulation.
Everglades National
Park (ENP) wetland water levels decreased. Stations in the south saw appreciable
decreases such as, -0.35
ft at
Despite lower
overall rainfall last week, salinity continued to decline or remain
stable across Fl Bay. Significant flow
through both
Water Supply
Water levels in the upper and lower
Five 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 and Lower
East Coast Service Areas 1, 2 and 3 are still in the high risk category.
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 “low” risk this week, and the LOK
Seasonal Inflow forecasts are at “medium” risk.
WSE
(
The current
CC: George
Horne