MEMORANDUM
TO: Chip
Merriam, Deputy Executive Director, Water Resources
FROM: SFWMD Staff Environmental Advisory Team
DATE: October 2, 2007
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No
regulatory releases
to the south or estuaries are recommended.
Background
Rains
should decrease but remain above average today, decrease further tomorrow
before increasing again the latter part of the week and into the weekend. A complex trough an attendant upper low has
moved westward into the eastern
The upper Kissimmee Basin received 0.37
inches of rainfall over the last 7 days to bring the September total to 4.62
inches (75% of average) and the lower basin received 0.64 inches to bring the
September total to 5.76 inches (96% of average). So far, the wet season has produced 24.91
inches (90% of normal for this portion of the wet season) for the upper basin
and 24.84 inches (96% of normal for the lower basin (Daily Rainfall Report for
10/01/07). Stages in most of the upper
basin lakes have been stable over the last seven days.
As lake stage went above schedule,
water has been released from
Flow has been reestablished to the
The most recent wading bird survey found the number
of foraging wading birds, primarily white ibis, had increased over the last two
months but was much lower than has been typical for September since Phase I of
Kissimmee River Restoration Project was completed. Waterfowl abundance has also increased with
the arrival of small groups of migrant blue-winged teal.
According to the USACE
web site,
During September, 20 of 27 water quality sampling
sites had sufficient water for sampling. Data from this sampling event should be
available this week. The October
submerged-aquatic-vegetation (SAV) monitoring is
being conducted this week.
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 |
|
1.5 |
1.6 |
|
HR1 (N. Fork) |
1.3 |
3.2 |
|
|
3.6 |
3.8 |
8.0 – 25.0 |
A1A Bridge |
12.8 |
20.0 |
20.0 – 31.0 |
Rainfall and associated local runoff lowered
average salinity throughout the estuary last week. Average salinity for the week was at the lower
limit or below the preferred at the Roosevelt and A1A
Bridges. Based on the salinity
tolerances of the oyster, Crassostrea virginica, salinity conditions in the estuary are poor
at the
Caloosahatchee Estuary
Discharge data for the full week were not available
at the time of writing. Between 9/25 and
9/30/2007 discharge at S-79 averaged 586 cfs. Average salinity decreased throughout the
estuary last week. Data for specific
sites are given below in parts per thousand (ppt). The
|
Weekly Average Salinity (ppt) |
|
Sampling Site |
Surface |
Bottom |
|
3.3 |
3.4 |
Rt. 31 Bridge |
3.7 |
3.7 |
I-75 Bridge |
3.2 |
4.7 |
|
NA |
NA |
|
14.5 |
17.4 |
Shell Point |
24.4 |
26.3 |
Salinity conditions throughout the system are good.
FWRI reports that
water samples collected this week detected Karenia
brevis, the
Water Conservation Areas
Water levels have increased
significantly for a second week, and all gauges recorded a good wet season
inundation (i.e., re-hydration) rate. A
maximum inundation of 0.62 ft per week was recorded in WCA-2A.
The lowest inundation (0.07 ft per week)
was recorded at gauge 62 (NW WCA-3A). Inundation rates were directly related to
rainfall patterns. As one would expect,
water levels are approaching more realistic wet season values of 2 ft to 3 ft. However, there are still many regions of the
Wetland stations received between
1.1 – 5.1” of rain. The weekly RAINDAR Everglades National Park (ENP)
spatially averaged basin-wide accumulation was just over 4” last week; though
even more impressive was the total of 10.5” for the C-111 basin just to east. ENP wetland water
levels increased as a result of this rainfall and flow from upstream. Stations in the south all saw impressive
increases in stage last week: 7.2” at
Salinity showed mixed trends across FL Bay last
week in conjunction with the spatial distribution of rainfall. Strong discharge moving out of the creeks
toward
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, an improvement from last 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 and 2A continue to be in
the “low” risk category and Water Conservation Area 3A is now at “medium”
risk. The CPC Precipitation Outlook
remains at “low” risk this week, and the LOK Seasonal
and Multi-Seasonal Net Inflow forecasts are now at “medium” risk.
WSE
(
The current
CC: George
Horne