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 6, 2009
SUBJECT: Weekly Environmental Conditions for Systems Operations
Summary
Discharge from Lake Kissimmee is approximately 451 cfs. Lake Okeechobee stage is 14.46 feet NGVD, which is 0.09 foot lower than a week ago, 0.17 foot higher than a month ago, 0.51 feet lower than it was a year ago, and 0.62 foot above the simulated average using the current regulation schedule. Salinity conditions in the Saint Lucie estuary are considered to be fair to 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 poor in the lower estuary. The week’s pan evaporation was 1.22 inches this week exceeding rainfall in the Greater Everglades. Salinity displayed mixed trends 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
Afternoon
showers and storms focused north. Highest moisture is over central
Florida Tuesday morning. Look for seabreeze
showers and storms to move east across the Kissimmee Valley with highest
coverage over the Upper Kissimmee. A secondary focus of seabreeze showers and storms should occur south through
east of the Lake. Regardless, lack of instability suggests a below
average coverage of storms today. Mid level high pressure progresses into
the northeast Gulf of Mexico Wednesday, then over the peninsula on Thursday
before continuing eastward into the Atlantic on Friday and Saturday. Look
for daily activity to decrease Wednesday and Thursday as this high moves
closer, then daily showers should increase by the weekend as the high moves
away from the peninsula. The next ten
days precipitation outlook is below average with low confidence.
Kissimmee Watershed
Over
the past week the Upper Kissimmee Basin received 0.1 inches of rainfall and the
Lower Kissimmee Basin received 0.0 inches. Total rainfall in the last 30
days was 4.8 inches in the Upper Basin and 3.5 inches in the Lower Basin (SFWMD
Daily Rainfall Report 10/6/2009).
Upper
Kissimmee Basin lakes are within 0.2 foot of their regulation schedules (USACE
Kissimmee River Report 10/5/09 and/or SFWMD OASyS DualTrend or LOGGERNET). Lakes Hart and Mary Jane are
0.1 foot above regulation schedule. Lakes Myrtle, Preston, Joel are 0.2
foot above regulation schedule. Lakes in the Alligator Chain are 0.1 foot
below regulation schedule. Lake Gentry is 0.1 foot above regulation
schedule. East Lake Tohopekaliga is 0.1 foot
above regulation schedule.
Lake Tohopekaliga is 0.3 foot above regulation schedule; daily
discharge at S61 is 12 cfs. Lakes Hatchineha and Cypress are 0.1 foot above regulation
schedule. Lake Kissimmee is 0.1 foot above regulation schedule.
Discharge at Lake Kissimmee (S65) is 451 cfs.
In the
Lower Kissimmee Basin (SFWMD OASyS Dual Trend or
LOGGERNET 10/6/2009) discharge at S65-A is 597 cfs.
Discharge at S65-C is 825 cfs with headwater stage at
approximately 35.6 feet. Discharge at S65-D is 786 cfs.
Discharge to Lake Okeechobee at S65-E is 878 cfs.
Water is receding on the Kissimmee River floodplain in the Phase I restoration
area, with water depths averaging approximately 1.2 feet (SFWDAT 10/4/2009).*
River
channel dissolved oxygen concentrations (DO) in the Phase I area averaged 2.6
mg/L over the past week, above the level of concern.
Lake Okeechobee
According to the USACE web site, Lake Okeechobee stage is 14.46 feet NGVD, which is 0.09 foot lower than a week ago, 0.17 foot higher than a month ago, and 0.51 foot lower than a year ago. The current stage is 0.50 foot below the historical average for this date and 0.62 foot above the simulated average using the current regulation schedule (LORS2008). Total reported inflows are 1237 cfs and include flows through S65E (724 cfs), S71 (253 cfs), S84 (81 cfs), S191 (62 cfs), and Fisheating Creek (117 cfs). Direct rainfall on the Lake during the past week was less than 0.01 foot according to seven-day Raindar. Reported outflows are 386 cfs and include the L8 at Canal Point (241 cfs) and S354 (140 cfs).
Apple snail egg surveys were conducted at four snail release sites just north of Fisheating Bay. A total of 4500 hatchery-reared snails were released at this site on July 21, 2009. Twenty-three transects (3450 m2) were surveyed within these areas, and a total of 79 egg clutches were detected. Water depths at these locations ranged between 1.2 and 1.6 m. Large numbers of snail egg clutches were observed at other locations in the littoral zone as well this week.
Saint Lucie Estuary*
Over the past week, flow averaged 89 cfs at S-80 and 0 cfs at S308. Provisional data indicates that discharge of 121 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 St. 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) |
5.8 (2.7) |
7.9 (4.2) |
|
HR1 (N. Fork) |
8.9 (4.5) |
14.7 (8.1) |
|
Roosevelt Bridge |
12.3 (8.4) |
15.5 (10.9) |
8.0 – 25.0 |
A1A Bridge |
18.1 (15.1) |
24.1 (23.4) |
20.0 – 31.0 |
Average salinity increased over
the last week. Weekly average salinities at Roosevelt Bridge and A1A
Bridge (bottom salinity) are within the preferred range, surface salinity at A1A
Bridge is below the preferred range. Salinity conditions in the estuary
are fair to 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 929 cfs at S-79, 434 cfs at S-78, and 0 cfs at S-77. The concentration of chlorides at the Olga Plant was 51 ppm on Monday. 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) |
0.2 (0.2) |
Rt. 31 Bridge |
0.2 (0.2) |
0.3 (0.2) |
I-75 Bridge |
0.3 (0.3) |
0.3 (0.5) |
Ft. Myers Yacht Basin |
NR (NR) |
NR (NR) |
Marker 52 |
2.8 (2.3) |
5.4 (8.7) |
Cape Coral Bridge |
7.9 (6.6) |
9.0 (11.4) |
Shell Point |
21.6 (20.3) |
22.7 (22.4) |
Conditions in the upper estuary
west of Fort Myers remained similar to last week, with surface waters being
fresh to Marker 52. In the lower estuary salinity, salinity decreased in
bottom water and increased in surface water, except at Shell Point where salinity
increased at both sensors. 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, and the range preferred by seagrass, Halodule wrightii. Therefore, conditions in the lower
estuary are poor.
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, Hillsborough, Manatee, Lee and Collier counties or offshore of Sarasota County. Samples collected alongshore of Sarasota County ranged from present to very low in five samples (out of 28 total samples). Two samples collected alongshore of Charlotte County also contained background levels of K. brevis).
Monitoring data collected by the River, Estuary and Coastal Observing Network of Sanibel-Captiva Conservation Foundation indicated that chlorophyll ranged from 4.0 – 11.0 ug/l at Fort Myers and 1.6 – 5.8 ug/l at Shell Point. DO ranged from 1.8 – 7.7 mg/l at Fort Myers and 3.0 – 6.7 mg/l at Shell Point.
Water Conservation Areas
(WCA)
With
this week’s pan evaporation of 1.22 inches* exceeding rainfall, stages declined
throughout the Greater Everglades except in WCA-2A.*
Stage Change:
WCA-1:
-0.04 foot
WCA-3A:
-0.12 foot
WCA-2A:
0.07 foot
WCA-3B:
-0.11 foot
WCA-2B:
-0.22 foot
NESRS:
-0.08 foot
Water
depths have remained above 2.5 feet in southern WCA-2B for 86 days and in
southern WCA-3A for 56 days*. Inundation of tree islands above 2.5 feet
is tolerated by most trees on the islands for 90 to 120 days, after which the
trees grow increasingly stressed physiologically.
Marsh
water stages in WCA-1 are 0.8 foot below regulation in zone A2 and declining,
now approaching Zone B. In WCA-3A stages have dropped almost to the upper
transition zone.
Stages
continue to rise in WCA-2A; they are about 0.5 foot above regulation compared
to 0.35 foot last week.* Inundation of the conservation areas has expanded;
areas deeper than 2.5 feet are expanding westward in southern WCA-3A and
northward in WCA-2A, -2B, and 1.* Water levels
in the previously dry section of northern WCA-3A (east of the Miami Canal) have
risen above ground again. Greater Everglades depths are slightly lower than those
a week ago, slightly higher than they were a month ago, and lower than a year
ago.*
Everglades National Park
Light rain fell across Everglades National Park (ENP) and moderate rain fell across Florida Bay (Bay) last week with ENP stations measuring 0 – 5.1 inches of rainfall. The basin-wide, spatially-averaged weekly totals were 0.5 and 0.9 inch for the ENP and C-111 basins, respectively.
Stages* declined across most ENP wetland stations last week. Water levels in Shark River Slough and at the Taylor Slough Bridge each declined 0.5 inch. To the south, water levels in the ENP panhandle increased 0.4 inch but declined 1.1 inches in Craighead Basin.
Salinity* displayed mixed trends across Florida Bay. While last week’s near shore eastern Bay salinity declined slightly to 9 psu in Long Sound, it increased from 20 psu to 26 psu at the Little Madeira Bay platform. Further into the Bay in Duck Key basin, salinity declined from 36 psu to 29 psu. The 30 day moving average salinity at the Taylor River platform (used for tracking the Florida Bay minimum flow and levels) declined slightly from 1.0 psu to 0.8 psu, with the daily mean salinity at 0.7 psu. In the north central Bay, salinity declined slightly to 11 psu in McCormick Creek but increased from 14 psu to 19 psu in Terrapin Bay. At the central Bay platform in Whipray Basin, salinity declined slightly to 38 psu. To the west, in the upstream reaches of Shark River Slough, salinity is 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 are 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 20 to over 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 30th percentile in southwestern Martin County and northern Palm Beach County. In the Lower East Coast, groundwater levels in the USGS network are at median values or higher for most wells, with the highest levels occurring in coastal Broward County. There are a few wells in Miami-Dade County along the coast and near a rock mining operation south of US 41 near Krome Avenue that have dropped to the lowest 30th percentile. Surficial aquifer wells in the Lower West Coast (LWC) have risen to median or higher 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_06.zip
CC: George Horne