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: April
14, 2009
SUBJECT: Weekly
Environmental Conditions for Systems Operations
Summary
Discharge from
Background
Strong
storms extreme north on Tuesday. A
pre-frontal line of heavy showers and strong storms is moving into the
Over the last
seven days, the upper Kissimmee Basin received 0.03 inches of rainfall and the
lower Kissimmee Basin received 0.05 inches to bring the monthly totals to 1.10
(38% of average) and 1.71 (66% of average) inches respectively (Daily Rainfall
Report 4/13/09).
Stage in Lakes
Kissimmee, Hatchineha and
Hydrilla treatments are scheduled for Lakes Kissimmee, Hatchineha and Jackson on April 14 through April 16, 2009.
Snail kites continue to nest
on
Discharge from
Over the last
seven days, dissolved oxygen (DO) concentrations in the
According to the United
States Army Corps of Engineers (USACE) web site,
The “dry out” lake stages for
33 sites in the North, West and Fisheating Bay (FEB)
that currently have sparse to dense beds of submerged aquatic vegetation (SAV)
was predicted based on water depths recorded during the January to April SAV
surveys (Dry out stages Apr 09 OPS.ppt).
These predicted “dry out” stages indicate that if lake stage reaches
10.0 feet. NGVD then half (17 of 33) of the sites that currently have SAV would
go dry eliminating the SAV from those site. In the North, 11 of the 18 SAV sites would go
dry and three SAV sites in each of the West and FEB areas would go dry. All of the sites along the western wall have
dense beds of topped out and reproductive Vallisneria
so fostering conditions that would allow the lake stage to remain above 10.5 feet
would be beneficial to SAV maintenance and continued growth. After the 2000 drought it took two to three
years for sparse beds of SAV to emerge in areas that had been dry.
March water-quality monitoring results are now available.
Two of the 25 monitoring stations (FEBIN and FEBOUT) were not sampled due to
low water conditions. Total phosphorus
averaged 124 ppb lakewide (compared to 138 ppb in
February) and 104 ppb at nearshore stations (compared
to 125 ppb in February). Total suspended
solids averaged 21 ppm lakewide
(compared to 22 ppm in
February) and 18 ppm at nearshore
stations (compared to 20 ppm in February).
Saint Lucie Estuary
Over the past week, no flow
was discharged at S-80. Discharge from the
Weekly
Average Salinity (ppt) |
|
||
Sampling
Site |
Surface |
Bottom |
Envelope |
|
20.7
(20.3) |
21.1
(21.3) |
|
HR1
(N. Fork) |
23.8 (23.2) |
24.6 (23.9) |
|
|
26.2 (25.8) |
26.5 (26.1) |
8.0
– 25.0 |
A1A
Bridge |
30.4 (30.3) |
32.1
(31.7) |
20.0
– 31.0 |
Salinity throughout the
estuary remained about the same with last week. At both the Roosevelt and A1A Bridges, weekly
average salinity is slightly above the upper bound of the preferred range. Salinity conditions in the estuary are
considered to be fair considering the time of year, the location in the
estuary, and salinity preference of the oyster, Crassostrea
virginica.
Caloosahatchee Estuary
During the past week,
discharge averaged 578 cfs
at S-79, 493 cfs at S-78, and 903 cfs
at S-77. The concentration of chlorides
at the Olga Plant was 120 ppm on Monday. The current weekly average salinities (in
bold) at the six monitoring sites in the Caloosahatchee Estuary are given below
in parts per thousand (ppt), along with the previous
week’s (in parenthesis).
Weekly Average Salinity (ppt) |
||
Sampling
Site |
Surface |
Bottom |
|
5.5 (5.5) |
6.4
(6.2) |
Rt.
31 Bridge |
7.6 (7.5) |
9.0 (9.0) |
I-75
Bridge |
9.7
(9.4) |
11.4 (13.0) |
|
17.8
(18.6) |
18.6
(19.0) |
|
25.9
(26.3) |
26.9
(27.0) |
Shell
Point |
34.2
(34.3) |
35.2
(35.2) |
A seven-day pulse release at
S-79 began on Saturday, April 11, 2009. Average salinity remained about the same for
most part of the estuary except for a slight decrease between
Fish and Wildlife
Research Institute reports that water samples collected alongshore between
Pinellas and Monroe counties contained no K.
brevis. (Monitoring data collected by the River, Estuary and Coastal
Observing Network (RECON) of Sanibel-Captiva Conservation
Foundation (SCCF) indicated chlorophyll at Fort Myers and Shell Point ranged
from 1 to 7 mg/L (DO was unavailable).
Water Conservation
Areas
Regional pan
evaporation of 1.93 inches drove continuing large stage decreases throughout
the Greater Everglades. Water levels are falling at rates considered fair or good
throughout the WCAs, but
are particularly high in WCA-2A and Northeast Shark River Slough, -0.24
and -0.31 foot, respectively:
Stage Change: WCA-1: -0.16 foot WCA-3A: -
0.19 foot
WCA-2A: -0.24 foot WCA-3B: - 0.19 foot
WCA-2B: -0.19 foot NESRS: - 0.31 foot
All WCAs are far below their regulation schedules. WCA-1 is about -0.5 foot below, WCA-2A canal
stage (used from February to May) has fallen again to about -0.9 foot below,
and the WCA-3A marsh is about -0.6 foot below the bottom of Zone E1.
Water depths are largely
below ground in much of the Greater Everglades.
Except for coastal areas, Everglades National Park (ENP) is dry, with
soil water depths well below -1 foot in most of the Park. Similarly, Big Cypress Preserve water tables
are -2 feet or more below ground level. Surface water remains only in
WCA-1, WCA-2B, WCA-3A, and WCA-3B. Subsurface water depths continue to
drop in the WCA-2A and -3A, Holeyland, and Rotenberger. These
water depths increase loss of peat through decomposition and provide higher
possibilities of muck fires.
Most of the Greater Everglades
have moved into the moderate muck fire risk category except for the wetter
areas described above and along the coastal regions of ENP. There is a high risk of muck fires in far
northern WCA-3A, portions of WCA-2A, along
Wading bird feeding
conditions remain surprisingly good in most of WCA-1 and middle WCA-3A and -3B. The southwestern coastal areas of ENP are
also showing good recession rates and depths for wading bird feeding, an
improvement over last week.
No appreciable rain fell
across ENP or
Stages continued to drop last
week. Water level in Shark River Slough has dropped by 4.6 inches since
3/29 (not reported 4/5), and water level at the
Salinity remained steady or
increased slightly in
The
Water Supply
Groundwater levels across the
District continue to decline. Floridan aquifer
wells in the
Water supply risk indicators
in the “low” risk category include the Water Conservation Areas 1 and 3A.
The LOK Seasonal Net Inflow Forecast and the LOK Multi-Seasonal Net Inflow
Forecast have also moved into the “low” risk category. The CPC Precipitation Outlook, the Palmer
Index for LOK Tributary Conditions, and the projected LOK Stage for the next
two months continue in the “medium” risk category. The water supply risk indicator for the entire
LEC is in the “medium” risk category, with two days per week watering
restrictions in place except for the utilities at risk. Water Conservation Area 2A remains in the
“high” risk category, with headwater elevation at S11B below Line 2 (10.12 feet).
LORS2008 (
Stages in
On Saturday, April 11, the
Corps initiated a nine-day pulse release to the Caloosahatchee Estuary that
will average 650 cfs per day.
CC: George Horne