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 8,
2008
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No
Lake Okeechobee regulatory releases to
the south or estuaries are recommended.
Background
Afternoon showers and storms mainly west through north of
Over the last
seven days, the upper Kissimmee Basin received 0.92 inches of rainfall to bring
the 30 day total to 7.68 inches (106% of average), and the lower basin received
3.20 inches to bring the 30 day total to 10.34 inches (151% of average).
Decreased
rainfall over the upper basin relative to the previous two weeks slowed or
ended the rise in water levels that had been occurring in most of the
lakes. Releases were made temporally at
S-62 (
In the upper basin, snail
kites continue to nest on East Lake Toho,
Flow has been
reestablished to the
Dissolved oxygen
concentrations in the river channel of the
According to the USACE web site,
Total reported inflows are
4105, with most flow coming from the
June water-quality monitoring
results are now available. Thirteen of
the 25 monitoring stations had sufficient water for sampling. Total phosphorous averaged 80 ppb lakewide (compared to 185 ppb in May) and 25 ppb at nearshore stations (compared to 52 ppb in May). Total suspended solids (TSS)
averaged 22 ppm lakewide
(compared to 68 ppm in May) and 4 ppm at nearshore stations
(compared to 14 ppm in May).
The monthly
submerged-aquatic-vegetation (SAV) survey was
completed yesterday. Twenty seven sites
had sufficient water for sampling, and all sites had water clarity conducive to
plant growth (secchi depth > 50% of total depth). The macroalga Chara remains the dominant SAV
species and was found at 12 of the 27 sites.
The vascular SAV species Vallisneria
americana was present 7 of the 16 sites sampled
near the northern and western shorelines but continues to be absent in the
south (11 sites sampled). For the first
time in over a year, the southern naiad (Najas
guadalupensis) was found in very low density in
the southern region (west side of Ritta
St. Lucie Estuary
There were no releases through
S-80 from C-44 over the past week. An
average discharge of 348 cfs through S-48 from C-23
and 292.4 cfs through S-49 from C-24 occurred over
the past week. The current weekly
average salinities (in bold) at the four monitoring sites in the St. Lucie are
given below in parts per thousand (ppt), along with
the previous week’s (in parenthesis).
|
Weekly Average Salinity
(ppt) |
|
|
Sampling Site |
Surface |
Bottom |
Envelope |
|
6.91 (13.15) |
8.06
(15.43) |
|
HR1 (N. Fork) |
7.47 (14.72) |
11.67 (17.95) |
|
|
11.39 (18.30) |
12.45 (19.15) |
8.0 – 25.0 |
A1A Bridge |
19.55
(24.68) |
20.12 (NA) |
20.0 – 31.0 |
Compared with salinities of
the previous week, average salinity decreased throughout the estuary due to
local runoff. Salinity declined between
5 ppt and 7 ppt depending
on location and depth. Salinity at
Caloosahatchee Estuary
An average weekly discharge
of 688 cfs occurred at S-79. The concentration of chlorides at the Olga
Plant was 102 ppm yesterday, down from 130 ppm in the beginning of this reporting period. Current weekly averages (in bold) may be
compared to last week’s data (in parenthesis).
Weekly Average Salinity
(ppt) |
||
Sampling Site |
Surface |
Bottom |
|
5.86 (7.79)
|
6.24
(8.15) |
Rt. 31 Bridge |
5.91
(7.96) |
8.63
(11.74) |
I-75 Bridge |
6.42
(10.08) |
12.03
(15.71) |
|
4.56
(18.31) |
17.18
(21.32) |
|
23.93
(26.68) |
24.45
(26.99) |
Shell Point |
33.11
(33.03) |
33.36
(33.30) |
Compared to last week,
average salinities dropped between 2 ppt and 4 ppt except at Shell Point where salinity stayed the same. Average salinity at the
No Karenia brevis, the
Water Conservation
Areas
Last week we saw
a reprieve for the wading birds and their ability to feeding their fledglings
because good recession rates occurred in quite a few locations. However, this week, the foraging period has
officially ended everywhere in the EPA, because all areas had significant stage
increases and all are too deep for wading bird foraging. Water levels increased by an amazing 0.67 ft
(8 inches) in WCA-2A. The smallest increase in stage was in WCA-1 (0.06 ft or ¾ inch). Depths range from a low of 1.13
feet in WCA-3B to a high of 2.05 ft in the southern
region of WCA-3A (the L-67 c and d levees work to
maintain this hydrologic disparity).
Stages are
currently above regulation in all three Water Conservation Areas.
Spatially variable rainfall
again produced mixed trends for Everglades National Park (ENP)
wetland water levels. Shark River Slough
(station P33) water level was nearly unchanged from last week (despite having
receiving approx. 1.5” of rain for the week). Water level dropped by nearly 2” (falling just
beneath ground surface) for the week at
Salinity trends across
Water Supply
Did not Report Week of July
8, 2008
LORS2008 (
The current
CC: George Horne