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
18, 2007
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No regulatory releases to the south or estuaries are recommended.
Background
Scattered
mainly afternoon thunderstorm activity. Good moisture and favorable upper level wind
flow should help generate an above average thunderstorm day today. Morning shower activity along the east coast
will shift to the interior and west this afternoon. As drier air moves into the area, daily
coverage of thunderstorm activity will drop down Wednesday through Friday but
remain focused over the interior and west.
Activity will then focus over the interior Saturday. The next ten days
precipitation outlook is near average with moderate confidence.
The upper Kissimmee Basin received 1.26
inches of rainfall over the last 7 days to bring the total for the month to
4.69 inches (139% of average) and the lower basin received 1.88 inches to bring
the total for the month to 6.24 inches (203% of average) (Daily Rainfall Report
for 7/16/07).
Last Friday (July 13), USFWS
provided a snail kite update for Toho - 4 new nests were found. Currently, snail kites have 20 active nests
on the lake, including several that contain eggs. This indicates
that the snail kite nesting season may be extended this year.
In the upper basin, lake stages have
remained fairly stable over the last seven days. Small releases of approximately 150 cfs continue to be made from
The
Water levels in Pool C have risen
approximately 0.25 ft from rainfall and runoff.
Concentration of dissolved oxygen in the Phase I restored river channel
has fallen below thresholds of concern.
One station (KRBN) has fallen to 1.56 mg/L in
the last few days and the other station (PC62) has
been measuring values much less than 1 mg/L for the last seven days.
On Wednesday July 11th, measurements of
dissolved oxygen in the restored river channel indicate a strong gradient of
decreasing concentration from surface to the bottom at two locations (PC62 and KRBN). At PC62, DO
concentration was 3 mg/L at 0.5 meters and 0.61 near the bottom of the channel.
At KRBN, DO concentration was 6 mg/L at 0.5 m
and 0.75 mg/L near the bottom.
Algal bloom reported in Pool D section
of the C-38 but not in Pool C (Monday July 16).
According to the USACE
web site,
The monthly bloom sampling is complete and no
blooms were reported at any of the 6 sites visited. Light penetration was good
with Secchi Depth to Total Depth ratios greater than
0.5 at all but one of the sites. Toxin data are not yet available.
St. Lucie Estuary
No releases occurred at S-80 over the past
week. Salinity continued to decline due
to local runoff. At the
Caloosahatchee Estuary
Discharge averaged 161 cfs
last week. Chloride concentration at the Olga Plant is presently 91
mg/l. Weekly average surface salinity
continued to decline and ranged from 5.3 ppt at S-79
to 14.6 ppt at
There have been reports of anoxic bottom water
around the Route 31 Bridge. District
staff completed a survey on July 10, 2007 and detected hypoxic bottom water
(dissolved oxygen concentration < 2.00 mg/l) extending from just downstream
of S-79 to Marker 27 near
FWRI reports that
no Karenia brevis,
the
Water Conservation Areas
With the summer rainfall, average stages increased
by 0.09 ft this week. Stages increased
up to 0.48’ in the more northern areas, but they receded in part of WCA-3A, 3B, and northeast Shark River Slough. WCA-2B is finally acting as one would expect—both gauges
reported an increase, consistent with reported marsh water levels.
All stations in the WCA’s
are now reporting surface water ranging from 0.55’ to 1.48’. WCA-1 is at regulation, WCA-2 is
above, and WCA-3 is below Regulation.
Rainfall was patchy across Everglades National Park
(ENP) and
Water levels were either stationary or retrograde
last week across the ENP wetlands. Water levels remained virtually unchanged in
Shark River Slough at P33 but were lower to the south. This week, stages declined by 1.4” in the ENP panhandle and by 0.8” to the west at Craighead Pond
(CP).
Salinity continued decreased or remained low across
Water Supply
Water levels in the
Four out of eleven water supply risk measures are
in the “high” risk category this week.
The projected Lake O Stage (SSM), 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 Lake Okeechobee Multi-seasonal Net Inflow
Forecast and the Palmer Index for Tributary Conditions are now at medium
risk. The CPC Precipitation Outlook
remained at “low” risk this week, along with the LOK
Seasonal Net Inflow forecasts.
Regarding “Utilities of Concern”, the water supply
dept. has reduced the reporting frequency of most systems from weekly to monthly,
in response to improved wet season conditions.
A study of drought-related surcharges implemented or proposed by the LEC utilities also has been initiated
WSE
(
The current
CC: George
Horne