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 27, 2009
SUBJECT: Weekly Environmental Conditions for Systems Operations
Summary
Discharge from Lake Kissimmee is currently 190 cfs. Lake Okeechobee stage is 14.14 feet NGVD, which is 0.05 foot lower than a week ago, 0.42 foot lower than a month ago, 0.77 foot lower than it was a year ago, and 0.13 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 1.24 inches this week. Groundwater levels across the District are slowly declining with the arrival of the dry season.
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
Scattered showers mainly west and north on Tuesday.
Moisture has returned to the District from the south which should help fuel
some afternoon thunderstorm development Tuesday and Wednesday. Activity
will be fast-moving Tuesday and be focused west and north. Activity will
then be focused over the interior Thursday. As the moisture exits to the
northeast, expect daily shower activity to be very limited Thursday, Friday,
and Saturday. The next cold front is forecast to move into north-central
Florida and stall Saturday night. The
next ten days precipitation outlook is below average with low confidence.
Kissimmee Watershed
Over
the past week the Kissimmee Basin received less than 0.1 inch of
rainfall. For the month so far, rainfall was 39% and 17% of normal in the
Upper and Lower Basins, respectively. Total rainfall in the last 30 days
was 2.5 inches in the Upper Basin (75% of normal) and 1.3 inches in the Lower
Basin (40% of normal) (SFWMD Daily Rainfall Report 10/26/2009).
Lakes
in the Kissimmee Chain of Lakes are within 0.9 foot of their regulation
schedules (USACE Kissimmee River Report 10/26/09 and/or SFWMD OASyS DualTrend or
LOGGERNET). Lakes Hart and Mary Jane are 0.7 foot below regulation
schedule. Lakes in the Alligator Chain are 0.8 foot below regulation
schedule. Lake Gentry is 0.2 foot below regulation schedule. East
Lake Tohopekaliga is 0.6 foot below regulation schedule. Lake
Tohopekaliga is 0.2 foot below regulation schedule; discharge at S61 is 0
cfs. Lakes Hatchineha and Cypress are 0.8 foot
below regulation schedule. Lake Kissimmee is approximately 0.9 foot below
regulation schedule. Discharge at Lake Kissimmee (S65) is 190 cfs.
In the
Lower Kissimmee Basin (SFWMD OASyS Dual Trend
or LOGGERNET 10/27/2009) Discharge at S65-A is 209 cfs, discharge at S65-C is
131 cfs with headwater stage at 35.7 feet. Discharge at S65-D is 112 cfs, discharge to Lake Okeechobee at S65-E is 153 cfs.
Water depths continue to recede on the floodplain in the Kissimmee River Phase
I restoration area, averaging 0.8 foot (SFWDAT 10/25/2009). SFWDAT depth and
difference maps are attached.
River
channel dissolved oxygen (DO) concentrations in the Phase I area averaged 5.4
mg/L over the past week, well above the level of concern. The Vegetation
Management Division will be treating water lettuce and water hyacinth this week
in river channels in Pools D and E.
Lake Okeechobee
According to the USACE web site, Lake Okeechobee stage is 14.14 feet NGVD for the period ending at midnight October 26, 2009, which is 0.05 foot lower than a week ago, 0.42 foot lower than a month ago, and 0.77 foot lower than a year ago. The current stage is 0.92 foot below the historical average for this date and 0.13 foot above the simulated average using the current regulation schedule (LORS2008). Total reported inflows are 181 cfs and include flows through S65E (156 cfs),S129 (6 cfs), S131 (6 cfs),and Fisheating Creek (18 cfs). S133 is not reporting. According to the Raindar seven day average there was no direct rain fall over the Lake this past week. Lake outflows total 206 cfs, all of it through S77 with the L8 at Canal Point not reporting.
Lake Okeechobee field crews traversing the pelagic zone this week reported no evidence of bloom conditions.
Monday, October 26, 2009 Florida Fish and Wildlife Conservation Commission began aerial treatments of 3000 acres of floating aquatic weeds. This is the first time this year that treatments will be within bulrush heads but bulrush are well along in their annual senescence so this is the best time of the year to do such treatments. Nevertheless, the resulting appearance of treated bulrush may cause concern among Lake users. The exotic grass Luziola is appearing in more places within the Lake. “Quite a few” purple swamp hens are reported nesting in the southern part of the Lake.
Saint Lucie Estuary*
Over the past week, flow averaged 0 cfs at S-80 and 25 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 |
HR1 (N. Fork) |
19.8 (16.3) |
21.1 (19.4) |
|
Roosevelt Bridge |
21.4 (19.0) |
22.3 (21.1) |
8.0 – 25.0 |
A1A Bridge |
28.4 (27.2) |
30.3 (29.2) |
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 64 cfs at S-79, 0 cfs at S-78, and 243 cfs at S-77. The concentration of chlorides at the Olga Plant was 58 ppm on Monday. The current weekly average salinities (in bold) at the six monitoring sites in the Caloosahatchee Estuary are given below in psu, along with the previous week’s (in parenthesis).
Weekly Average
Salinity (psu) |
||
Sampling Site |
Surface |
Bottom |
Franklin Locks (S-79) |
1.6 (0.5) |
1.7 (0.5) |
Rt. 31 Bridge |
1.8 (0.7) |
4.0 (1.0) |
I-75 Bridge |
2.1 (1.2) |
6.2 (2.4) |
Ft. Myers Yacht Basin* |
8.9
(6.0) |
14.3
(8.7) |
Marker 52 |
9.3 (6.4) |
16.1 (10.1) |
Cape Coral Bridge |
15.7 (14.3) |
19.6 (16.0) |
Shell Point |
26.6 (26.0) |
27.2 (26.8) |
Sanibel |
29.7 (30.2) |
31.0 (31.1) |
*red
values are estimated using a regression relationship between salinity at Marker
52 and salinity at Fort Myers.
Salinity increased throughout the estuary last week. Salinity conditions in the upper estuary are considered good. The estimated 30-day average salinity at Fort Myers is 4.9 psu. Salinities at the Cape Coral Bridge are within the preferred range for the oyster, Crassostrea virginica. Salinity at Shell Point and the Sanibel Causeway indicate 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 Pinellas, Manatee, Charlotte and Collier counties or offshore of Lee County. Six samples collected alongshore of Sarasota County (out of 27 total samples) and three samples collected alongshore of Lee County (out of 12 total samples) ranged from background to very low concentrations of K. brevis.
Monitoring data collected by the
River, Estuary and Coastal Observing Network (RECON) of Sanibel-Captiva Conservation Foundation indicated that chlorophyll
ranged from and 1.3 – 3.3 ug/l and DO ranged from 4.6
– 7.7 mg/l at Shell Point. Reading at Fort Myers were
unavailable.
Water Conservation Areas
(WCA)
This
week’s pan evaporation of 1.24 inches* exceeded rainfall in most conservation areas*,
but the stage declines were much lower than last week and stages rose in other
locations. Stages declined in WCA-1, -2A, and -3A, but
rose in WCA-2B, -3B, and northeast Shark River Slough.
Stage Change:
WCA-1:
-0.03 foot
WCA-3A:
-0.08 foot
WCA-2A:
-0.11 foot
WCA-3B
0.05 foot
WCA-2B:
0.21 foot
NESRS:
0.10 foot
Water
depth changes are mixed across the region*. They are continuing to drop
at gage 65 in southern -3B, the only gage where tree
islands occur and stages exceed 2.5 feet. Marsh water stages in WCA-1 are
0.5 foot below regulation in zone B and have remained steady over the
week. Stages in WCA-2A remain 0.5 foot above regulation and are
rising. In WCA-3A, stages have declined rapidly and are now slightly
below regulation.*
Water
depths in the conservation areas show overall declines relative to a month
ago.* Greater Everglades depths are lower now
than they were both a month ago and a year ago.*
Everglades National Park
Rainfall was light across Everglades National Park (ENP) wetlands and Florida Bay last week. Basin-wide amounts were 0.66 inches for the ENP and 0.58 inches for the C-111 basins.*
There is no report for the Park and for Florida Bay this week
Water Supply
Groundwater levels across the District are slowly declining. About half of both Floridan and Surficial wells in the Kissimmee Basin are at median water level values for this time of year, with the remainder dropping into the lowest 30th to 10th percentile range. Canal stages in the Upper East Coast (UEC) range from 18 to over 21 foot NGVD this week - well above the 14 foot agricultural pumping cutoff level. Groundwater levels in the UEC are gradually declining while remaining at expected values for this time of year in Saint Lucie County. UEC groundwater conditions are generally lower to the south – in the 30th percentile in Martin County and in the lowest 10th percentile far 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. There are several wells in Miami-Dade County south of US 41 near Krome Avenue that have dropped to below the lowest 10th percentile. Surficial aquifer wells in the Lower West Coast (LWC) are at median levels and slowly dropping as the dry season progresses. Most Lower Tamiami water levels in the USGS network in the LWC are in the median range for this time of year, also declining seasonally. Sandstone aquifer wells in the USGS network are declining and are mostly in the lowest 10th to 30th percentile range, with a few lower than ten percent and one at median levels. Mid-Hawthorn wells are mostly in the lower 10th to 30th percentile range. Levels in the Mid-Hawthorn appear to be steady rather than declining at present.
All water supply risk indicators remain in the “low” risk category. The projected LOK Stage for the next two months is 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 “ above normal” for both one month, 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 remain in the near normal category, but are decreasing 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_27.zip
CC: George Horne