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: August
21, 2007
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No
regulatory releases
to the south or estuaries are recommended.
Background
Increased rains beginning late tomorrow. Hurricane Dean has moved inland over the
The upper Kissimmee Basin received 0.45
inches of rainfall over the last 7 days to bring the 30-day total to 6.59
inches (96% of average) and the lower basin received 1.06 inches to bring the
total for the month to 6.25 inches (100% of average) (Daily Rainfall Report for
08/21/07).
Stages in most of the upper basin lakes have been
stable over the last seven days and are at schedule. The stage in
Snail kites continue to nest on
Flow has been reestablished to the
For the last week, the concentration of dissolved
oxygen in the river channel has remained above thresholds of concern with mean
daily values increasing from 2.32 mg/L on August 14 to 5.65 mg/L on August 19.
According to the USACE
web site,
This month 21 of the 27 water quality sampling
sites had sufficient water for sampling; however the results are not yet
available.
Approximately 8,000 acres of torpedograss
from the Indian Prairie marsh south to the Moore Haven marsh are currently
being treated at a rate of approximately 670 acres per day. The intent is to treat at least 12,000 acres
this year while lake levels are low.
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 |
|
2.9 |
3.9 |
|
HR1 (N. Fork) |
4.2 |
9.00 |
|
|
7.6 |
8.5 |
8.0 – 25.0 |
A1A Bridge |
15.0 |
20.1 |
20.0 – 31.0 |
Local freshwater inflow has caused surface salinity
at both the
Caloosahatchee Estuary
Discharge at S-79 averaged 246 cfs
over the past week. Chloride
concentration at the Olga Plant is presently 83 mg/l. Weekly average salinity at the monitoring
sites in the Caloosahatchee Estuary are given below in
parts per thousand (ppt).
|
Weekly Average Salinity (ppt) |
|
Sampling Site |
Surface |
Bottom |
|
5.9 |
6.0 |
Rt. 31 Bridge |
NA |
6.3 |
I-75 Bridge |
5.2 |
8.8 |
|
12.6 * |
NA |
|
18.4 |
19.1 |
Shell Point |
29.7** |
32.1** |
* average of past two
days; ** average of past 4 days; NA= not available
Since surface salinity exceeds 10 ppt at the
Water Conservation Areas
Changes in water depths for the Conservation Areas varied. All stations in WCA-1
reported decreases up to -0.1 foot from the week before, and stages in the
Everglades National Park (ENP)
wetland stations have reported no rain or stage data since last Thursday, so
stage data are missing for last week; nearby USGS
data were used to update conditions in these areas. ENP wetland water
levels displayed mixed trends for the week.
Water levels dropped by nearly 1” in southern Taylor Slough (at E146),
while they were up 1” to the east in the panhandle/C111 region, probably
because of local rainfall differences.
In Shark River Slough, water levels increased by nearly 0.5” (stations NE4 and NE5).
Salinity continued to remain seasonably low across
Water Supply
Water levels in the Lower West Coast (LWC) continue to remain near low levels for their periods
of record, and water levels generally decreased in the LWC
over the past week. Water levels
declined slightly in the coastal areas of the Upper East Coast and
Five out of eleven water supply risk measures are
in the “high” risk category this week including the projected Lake O Stage (SSM), the Palm Index for Tributary Conditions, 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 LOK Multi-Seasonal Net Inflow Forecast remains at medium
risk this week. The CPC Precipitation
Outlook remains at “low” risk this week, along with the LOK
Seasonal Net Inflow forecast.
WSE
(
The
current
CC: George
Horne