M E M O R A N D U
M
TO: Ken Ammon, Deputy Executive Director
Tommy Strowd, Assistant Deputy Executive Director
Terrie Bates, Assistant Deputy Executive Director
FROM: SFWMD Staff Environmental Advisory Team
DATE: October 13, 2009
SUBJECT: Weekly Environmental Conditions for Systems Operations
Summary
Discharge from Lake Kissimmee is currently 446 cfs and will be reduced to 250 cfs. Lake Okeechobee stage is 14.43 feet NGVD, which is 0.03 foot lower than a week ago, 0.01 lower than a month ago, 0.57 feet lower than it was a year ago, and 0.48 foot above the simulated average using the current regulation schedule. Salinity conditions in the Saint Lucie estuary are considered to be good based on the salinity preference of the oyster, Crassostrea virginica, and location in the estuary. In the Caloosahatchee Estuary, salinity conditions are good in the upper estuary, and good in the lower estuary. The week’s pan evaporation was 1.61 inches this week. Salinity was stable or declined across Florida Bay last week. Groundwater levels across most parts of the District around median values expected for this time of year.
The United States Army Corps of Engineers (USACE) 8-day pulse releases to the Caloosahatchee Estuary (2800 cfs) and Saint Lucie Estuary (950 cfs) ended Monday, August 3rd. Since that time, releases at S-79 and S-80 have been limited to basin runoff.
Background
Showers Friday,
then a little cooler for the weekend. High pressure and lower humidity
over the area will limit shower development Tuesday but a few isolated to
widely scattered showers should pop up mainly west Tuesday afternoon.
Daytime heating should generate some widely scattered showers mainly over the
interior Wednesday and then the interior and east Thursday. A cold front
is forecast to move into the District bringing scattered shower activity Friday
and Saturday morning with some cooler weather moving in behind the front for
the weekend. The next ten days precipitation
outlook is below average with low confidence.
Kissimmee Watershed
Over
the past week the Upper Kissimmee Basin received 0.6 inches of rainfall and the
Lower Kissimmee Basin received 0.2 inches. Total rainfall in the last 30
days was 3.7 inches in the Upper Basin and 2.4 inches in the Lower Basin (SFWMD
Daily Rainfall Report 10/3/2009).
Lakes
in the Kissimmee Chain are within 0.3 foot of their regulation schedules (USACE
Kissimmee River Report 10/12/09 and/or SFWMD OASyS DualTrend or
LOGGERNET). Lakes Hart and Mary Jane are 0.2 foot below regulation
schedule. Lakes in the Alligator Chain are 0.3 foot below regulation
schedule. Lake Gentry is approximately at regulation schedule. East
Lake Tohopekaliga is 0.1 foot below regulation schedule. Lake
Tohopekaliga is 0.3 foot above regulation schedule; discharge at S61 is 0
cfs. Lakes Hatchineha and Cypress are 0.1 foot above regulation
schedule. Lake Kissimmee is 0.2 foot below regulation schedule.
Discharge at Lake Kissimmee (S65) is currently 446 cfs and will be reduced to
250 cfs.
In the
Lower Kissimmee Basin (SFWMD OASyS Dual Trend or LOGGERNET 10/13/2009)
discharge at S65-A is 455 cfs. Discharge at S65-C is 757 cfs with headwater
stage at approximately 35.8 feet. Discharge at S65-D is 648 cfs.
Discharge to Lake Okeechobee at S65-E is 1100 cfs. Water depths on the
Kissimmee River floodplain in the Phase I restoration area average
approximately 1.1 feet (SFWDAT 10/11/2009).*
River
channel dissolved oxygen (DO) concentrations in the Phase I area averaged 2.0
mg/L over the past week, approximately at the level of concern.
Lake Okeechobee
According to the USACE web site, Lake Okeechobee stage is 14.43 feet NGVD for the period ending at midnight October 12, 2009, which is 0.03 foot lower than a week ago, 0.01 foot lower than a month ago, and 0.57 foot lower than a year ago. The current stage is 0.6 foot below the historical average for this date and 0.48 foot above the simulated average using the current regulation schedule (LORS2008). Total reported inflows are 710 cfs and include flows through S65E (615 cfs),S129 (31 cfs, S191 (17 cfs),and Fisheating Creek (47 cfs). Direct rainfall on the Lake during the past week averaged 0.58 inches according to seven-day Raindar. Lake outflows are negligible.
September water-quality monitoring results are now available. Water levels were sufficient to sample all of the 25 monitoring stations. Total suspended solids and total phosphorus concentrations decreased or were similar to the previous month in both the nearshore and pelagic regions. Total suspended solids averaged 11 ppm lakewide (compared to 15 ppm in August) and 8 ppm at nearshore stations (compared to 8 ppm in August). Total phosphorus averaged 65 ppb lakewide (compared to 82 ppb in August) and 54 ppb at nearshore stations (compared to 66 ppb in August).
The fall submerged-aquatic-vegetation (SAV) survey was completed last week. A total of 53 sites were sampled (27 in the north, 12 in the west, 14 in the south) and plants were found at 42 of those sites (21 in the north, 10 in the west, 11 in the south). Light penetration is good with Secchi Depth:Total Depth ratios >0.5 at 34 sites. Chara remains the dominant species in the south and is doing well with moderate to dense beds at most nearshore sites. Sparse beds of Vallisneria, Najas, and Potomageton were observed along the western shore and moderate to dense beds of Hydrilla dominate the sites in Fisheating Bay. The northern sites continue to be dominated by Ceratophyllum interspersed with sparse to moderate beds of Vallisneria, Hydrilla, and Najas.
Saint Lucie Estuary*
Over the past week, flow averaged 23 cfs at S-80 and 8 cfs at S308. Provisional data indicates that discharge of 0 cfs occurred at S-97 on C-23 and 0 cfs at S-49 on C-24. The current weekly average salinities (in bold) at the four monitoring sites in the Saint Lucie Estuary are given below in practical salinity units (psu), along with the previous week’s (in parenthesis).
Weekly
Average Salinity (psu) |
|||
Sampling
Site |
Surface |
Bottom |
Envelope |
Palm City
Bridge (S. Fork) |
9.8 (5.8) |
11.3 (7.9) |
|
HR1 (N. Fork) |
11.8 (8.9) |
15.0 (14.7) |
|
Roosevelt
Bridge |
15.6 (12.3) |
16.8 (15.5) |
8.0 –
25.0 |
A1A Bridge |
22.6
(18.1) |
26.3 (24.1) |
20.0 – 31.0 |
Average salinity increased over
the last week. Weekly average salinities at Roosevelt Bridge and A1A
Bridge are within the preferred range. Salinity conditions in the estuary
are good considering the time of year, the location in the estuary, and
salinity preference of the oyster, Crassostrea virginica.
Caloosahatchee Estuary*
During the past week, flow averaged 298 cfs at S-79, 209 cfs at S-78, and 0 cfs at S-77. The concentration of chlorides at the Olga Plant was 58 ppm yesterday. The current weekly average salinities (in bold) at the six monitoring sites in the Caloosahatchee Estuary are given below in practical salinity units (psu), along with the previous week’s (in parenthesis).
Weekly
Average Salinity (psu) |
||
Sampling
Site |
Surface |
Bottom |
Franklin Locks
(S-79) |
0.2 (0.2) |
0.3 (0.2) |
Rt. 31 Bridge |
0.3 (0.2) |
0.3 (0.3) |
I-75 Bridge |
0.3 (0.3) |
0.8
(0.3) |
Ft. Myers
Yacht Basin |
NR (NR) |
NR (NR) |
Marker 52 |
3.7 (2.8) |
8.9 (5.4) |
Cape Coral
Bridge |
10.7 (7.9) |
14.3 (9.0) |
Shell Point |
25.3 (21.6) |
25.5 (22.7) |
Surface salinity in the upper estuary
west of Fort Myers remained similar to last week, with surface waters being
fresh to Marker 52, salinity increased in bottom water. In the lower
estuary, salinity increased last week. Salinity conditions in the upper
estuary are considered good. Salinities at the
Cape Coral Bridge are below the preferred range for the oyster, Crassostrea
virginica. Salinity at Shell Point indicates that conditions are good
for seagrass in the lower estuary and San Carlos Bay. Therefore,
conditions in the lower estuary and San Carlos Bay are good.
Fish and Wildlife Research Institute reports that Karenia brevis, the Florida red tide organism, was not detected in water samples collected this week alongshore of Manatee, Lee and Collier counties. One sample collected at Gasparilla Fishing Pier (Charlotte County) also contained very low concentrations of K. brevis. A research cruise currently being conducted offshore of southwest Florida has detected levels of K. brevis ranging from background to low concentrations offshore of Lee and Collier counties, west and south of Sanibel Island.
Monitoring
data collected by the River, Estuary and Coastal Observing Network of
Sanibel-Captiva Conservation Foundation indicated that chlorophyll ranged from
3.0 – 8.3 ug/l at Fort Myers and 1.1 – 3.4 ug/l at Shell Point; DO ranged
from 2.5 – 7.2 mg/l at Fort Myers and 3.3 – 5.6 mg/l at Shell Point.
Water Conservation Areas
(WCA)
With
this week’s high pan evaporation of 1.61 inches*, stages declined throughout the
Greater Everglades in patterns more typical of winter than the wet season*:
Stage Change:
WCA-1:
-0.09 foot
WCA-3A:
-0.15 foot
WCA-2A:
-0.08 foot
WCA-3B:
-0.07 foot
WCA-2B:
-0.19 foot
NESRS
-0.07 foot
Water
depths are now dropping so the tree island inundation durations appear to be in
their declining phases*. Marsh water stages in WCA-1 have dropped below
zone A2 and are 0.1 foot into zone B. In WCA-3A stages have re-entered
the upper transition zone after weeks of exceeding this zone. Stages in
WCA-2A are about 0.8 foot above regulation*.
Inundation
of the conservation area greatly resembles that of a month ago*. Greater
Everglades depths are lower now than a month ago and a year ago)*.
Everglades National Park
Light rain fell across Everglades National Park (ENP) wetlands and Florida Bay (Bay) last week. The basin-wide, spatially-averaged weekly RAINDAR totals were 0.5 and 0.2 inch for the ENP and C-111 basins, respectively*.
Stages declined across ENP wetland stations last week*. Water levels in Shark River Slough and at the Taylor Slough Bridge declined 0.6 and 3.0 inches, respectively. To the south, water levels in the ENP panhandle and in Craighead Basin declined 1.4 and 1.3 inches, respectively.
Salinity was stable or declined across Florida Bay last week*. In the near shore eastern Bay, salinity remained at 8 psu in Long Sound but declined from 25 psu to 20 psu at the Little Madeira Bay platform. Further into the Bay in Duck Key Basin, salinity remained at 31 psu. The 30 day moving average salinity at the Taylor River platform (used for tracking the Florida Bay minimum flow and level) declined slightly from 0.8 psu to 0.7 psu, with the daily mean salinity at 0.7 psu. In the north central Bay, salinity was steady near 11 psu in McCormick Creek and declined from 19 psu to 13 psu in Terrapin Bay. At the central Bay platform in Whipray Basin, salinity was stable at 38 psu. To the west, in the upstream reaches of Shark River Slough, salinity was fresh (< 0.5 psu).
Water Supply
Groundwater levels across most parts of the District are around median values expected for this time of year. Both Floridan and Surficial aquifer levels in the Kissimmee Basin has been slowly declining but are still generally at or above median values for this time of year, with the exception of a couple of Floridan wells in Polk and western Orange counties that have dropped into the lowest 30th percentile range. Canal stages in the Upper East Coast (UEC) range from 19.5 to 22 feet NGVD this week - well above the 14 foot agricultural pumping cutoff level. Groundwater levels in the UEC are at expected values for this time of year in Saint Lucie County and most of Martin County, and in the lowest 10th to 30th percentile in southwestern Martin County and northern Palm Beach County. In the Lower East Coast, groundwater levels in the United States Geological Survey (USGS) network are at median values for most wells, with the exception of North Miami and North Miami Beach area where they are in the lowest 10th to 30th percentile. Surficial aquifer wells in the Lower West Coast (LWC) have stabilized to median levels. Most Lower Tamiami water levels in the USGS network in the LWC are now in the median range. About half of the Sandstone aquifer wells in the USGS network are in the median range and the rest are in the lowest 10th to 30th percentile range. Mid-Hawthorn wells are mostly at median values for this time of year in Lee County and a bit below median in the two Collier County USGS wells.
All water supply risk indicators remain in the “low” risk category. The projected LOK Stage for the next two months is now in the Base Flow band. The Palmer Index for LOK Tributary Conditions is classified as “near normal”. The LOK Seasonal Net Inflow Forecast and the LOK Multi-Seasonal Net Inflow Forecast are both projected as “very wet”, and the CPC Precipitation Outlook is “normal” for one month and “above normal” for three months.
The Water Conservation Areas and the Lower East Coast service areas 1, 2 and 3 remain in the “low” risk category.
LORS2008 (Lake Okeechobee
Regulation Schedule)
Stages in Lake Okeechobee are now in the Base Flow Band. Tributary inflows are in the normal category. The seasonal outlook for net inflow into the Lake is for very wet conditions. The multi-seasonal outlook is also very wet.
The 2008 LORS Release Guidance Flowchart calls for releases up to 450 cfs at S-79 and up to 200 cfs at S-80. Given estuary conditions, the District recommends discharge to the Caloosahatchee and Saint Lucie Estuaries continue to be limited to basin run-off.
The 2008 LORS Release Guidance Flowchart also calls for releases to the WCAs if desirable or with minimum Everglades’ impact. The District does not recommend releases of Lake Okeechobee at this time.
* Go the FTP site for this week’s
Ecological Conditions supporting documents
ftp://ftp.sfwmd.gov/pub/ecsdocs/2009_10_13.zip
CC: George Horne