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
31, 2007
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No regulatory releases to the south or estuaries are recommended.
Background
Moderate thunderstorm coverage
today and Wednesday, then drier through the weekend.
An upper level trough continues to bring some favorable upper level wind-flow
today which is tapping ample moisture over the area. Scattered showers and thunderstorms have
developed again along the west coast and this activity should shift eastward
and increase in coverage through the day.
A weak surface low is forecast to develop in the northeast
The upper Kissimmee Basin received 1.27
inches of rainfall over the last 7 days to bring the 30-day total to 9.08
inches (136% of average) and the lower basin received 1.30 inches to bring the
total for the month to 9.61 inches (156% of average) (Daily Rainfall Report for
7/30/07).
Stages in the upper basin lakes are starting to
rise, especially in
Fish and Wildlife
Conservation Commission reports germination and growth of native submersed
aquatic vegetation, such as eelgrass (Valisneria)
and
Snail kites continue to nest on
Flow has been reestablished to the
The concentration of dissolved oxygen has fallen to
very low levels. The low oxygen
concentrations are probably related to the large contribution of basin runoff
to discharge through the restored reach.
Both river channel sites report values of 0.5 mg/L or less of dissolved
oxygen for the last week. At these low
levels, a fish kill is possible. Low
oxygen concentrations two weeks ago may have allowed fish to acclimate to low
oxygen concentrations. Current water
levels should allow fish access to the floodplain where higher oxygen
concentrations have been measured in previous years.
A small algal bloom was noted by the boat ramp at
S65 between the SR 60 bridge and the navigation lock and probably consists of
algae just piled up in that corner due to wind action.
According to the USACE
web site,
This month’s water quality sampling was limited to
4 pelagic sites and 3 near shore sites.
At the 4 pelagic sites Total Phosphorus concentrations averaged 142 ppb
and Total Suspended Solids averaged 51 mg L-1. These levels are lower than last months
values of 216 ppb Total Phosphorus and 82 mg L-1 Total Suspended
Solids at these 4 pelagic sites. The 3
near shore sites were not sampled last month due to low lake levels so no
values are available for comparison.
The monthly algal bloom monitoring was conducted on
the 16th of this month and at that time no algal blooms were
reported and toxin levels were below the analytical level of detection (0.2 ug L-1).
However, an algal bloom was observed on the north end of the lake
extending approximately 2 miles northwest and 2 miles southeast of S191 last
week. Rainfall induced nutrient rich
inflows might stimulate more algal blooms, especially near major lake inflow
sites.
St. Lucie Estuary
No
releases occurred at S-80 over the past week.
At the
Caloosahatchee Estuary
The estimated weekly average discharge at S-79 was
about 370 cfs.
Chloride concentration at the Olga Plant is presently 88 mg/l. Average surface salinity did not change
appreciably in the upper estuary, with surface salinity ranging from 6.3 ppt at S-79 to 13.2 ppt at
FWRI reports that no Karenia brevis, the
Water Conservation Areas
Unlike
last week, when rainfall barely matched evaporation and some regions receded,
this week surplus rainfall translated into stage increases everywhere in the
Rainfall was
spatially variable across ENP and FL Bay last week
(weekly precipitation totals ranged from 0.25 – 4”. Platform communication issues prevented us
from providing a full week’s worth of data for the ENP
wetlands. Data through Thursday, 7/26,
suggest that water levels are quickly increasing as water flows southward. Over the 4 day period for which we have data, some of the stage increases were substantial
(~ 3” Taylor Slough. Bridge & at P33 in
Water Supply
Water levels in the
Five out of eleven water supply risk measures are
in the “high” risk category this week.
The projected Lake O Stage (SSM), the LOK Multi-Seasonal Net Inflow Forecast and Lower East Coast
Service Areas 1, 2 and 3 are all in the high risk category.
Water Conservation Areas 1, 2A and 3A are now in
the low risk category. The Palmer Index
for Tributary Conditions is now at medium risk.
The CPC Precipitation Outlook remained at “low” risk this week, along
with the LOK Seasonal Net Inflow forecast.
WSE
(
The
current
CC: George
Horne