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:                    November 3, 2009

 

SUBJECT:             Weekly Environmental Conditions for Systems Operations

 

Summary

 

Discharge from Lake Kissimmee is currently 234 cfs.  Lake Okeechobee stage is 14.04 feet NGVD, which is 0.10 foot lower than a week ago, 0.44 foot lower than a month ago, 0.71 foot lower than it was a year ago, and 0.08 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 1.22 inches this week.  Groundwater levels across the District are slowly declining.

 

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

 

Locally moderate rains possible along the east coast through Wednesday.  A weak frontal boundary extends through the Lake Okeechobee area.  Look for some showers to focus near this boundary with the best chance for rains near the coast of Martin/Saint Lucie counties.  This front will drift south to the Lower East Coast Wednesday before exiting on Thursday.  Some locally moderate rains are possible very near the coast through Wednesday  Residual light showers are expected Thursday before dry, quite breezy, and slightly cooler conditions prevail Friday through the weekend.  The next ten days precipitation outlook is near average with low confidence.

 

Kissimmee Watershed

 

In the Upper Kissimmee Basin over the past week the Kissimmee Basin received less than 0.2 inch of rainfall.  For the month so far, rainfall was 12% and 0% of normal in the Upper and Lower Basins, respectively.  Total rainfall in the last 30 days was 1.0 inch in the Upper Basin (34% of normal) and 0.6 inch in the Lower Basin (21% of normal) (SFWMD Daily Rainfall Report 11/2/2009).

 

Lakes in the Kissimmee Chain of Lakes are within 1.0 foot below their regulation schedules (USACE Kissimmee River Report 11/2/09 and/or SFWMD OASyS DualTrend or LOGGERNET).  Lakes Hart and Mary Jane are 0.9 foot below regulation schedule.  Lakes in the Alligator Chain are 0.9 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 0.3 foot below regulation schedule; discharge at S61 is 0 cfs.  Lakes Hatchineha and Cypress are 1.0 foot below regulation schedule.  Lake Kissimmee is approximately 0.9 foot below regulation schedule.  Discharge at Lake Kissimmee (S65) is 234 cfs.

In the Lower Kissimmee Basin (SFWMD OASyS Dual Trend or LOGGERNET 11/3/2009) discharge at S65-A is 166 cfs.  Discharge at S65-C is 447 cfs with headwater stage at 35.8 foot.  Discharge at S65-D is 439 cfs.  Discharge to Lake Okeechobee at S65-E is 43 cfs.

 

Water depths continue to recede on the floodplain in the Kissimmee River Phase I restoration area, averaging 0.8 foot (SFWDAT 11/1/2009)*

 

River channel dissolved oxygen (DO) concentrations in the Phase I area averaged 4.5 mg/L over the past week, well above the level of concern.

 

Okeechobee Field Station will be treating water lettuce and water hyacinth this week in the lower Pool BC area of the Kissimmee River.

 

Two of the 21 horses that have been roaming the floodplain have been captured and are under the care of Okeechobee County Animal Control.

 

Lake Okeechobee

 

According to the USACE web site, Lake Okeechobee stage is 14.04 feet NGVD for the period ending at midnight November 02, 2009, which is 0.10 foot lower than a week ago, 0.44 foot lower than a month ago, and 0.71 foot lower than a year ago.  The current stage is 0.99 foot below the historical average for this date and 0.08 foot above the simulated average using the current regulation schedule (LORS2008).  Total reported inflows are 57  cfs and include flows through S65E (43  cfs)and Fisheating Creek (14 cfs).  According to Raindar there was negligible rain directly over the Lake this past week.  Lake outflows total 688 cfs, including S77 (297 cfs), S354 (145 cfs) and S351 (246 cfs). S308 and the L8 at Canal Point are not reporting.

 

Current total coverage of floating aquatic vegetation on the Lake is estimated at 4000 acres.  One thousand acres of floating vegetation was treated in Fish Eating Bay last week from Mayaca Cut to Observation Island.  Treatment of approximately 2000 additional acres is planned.  District crews flying the Lake last week reported seeing large flocks of wading birds foraging in shallow areas in the Northwest marsh that have been cleared as a result of the torpedo grass control program.

 

Florida Fish and Wildlife Conservation Commission (FWC) reports seeing exceptional Chironomid blooms on the Lake.  Chironomids are an important food source for juvenile fish and other aquatic organisms and are key indicators of improved lake conditions.  Their abundance has been limited over the past several years.  FWC is also reported good young of the year numbers for Largemouth bass (a single transect in Fish Eating Bay yielded more fish than the entire lake wide electro fishing study in 2008).

 

Saint Lucie Estuary*

 

Over the past week, flow averaged 0 cfs at S-80 and 2 cfs at S308.  Provisional data indicates that discharge of 0.2 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)

18.9 (19.8)

20.9 (21.1)

 

Roosevelt Bridge

21.7 (21.4)

22.4 (22.3)

 8.0 – 25.0

A1A Bridge

27.9 (28.4)

29.8 (30.3)

20.0 – 31.0

 

Average salinity remained the same 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 0 cfs at S-79, 78 cfs at S-78, and 439 cfs at S-77.  The concentration of chlorides at the Olga Plant was 60 ppm on Monday, November 2nd.  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)

 4.4 (1.6)

5.5 (1.7)

Rt. 31 Bridge

 5.3 (1.8)

10.2 (4.0)

I-75 Bridge

 5.6 (2.1)

11.1 (6.2)

Ft. Myers Yacht Basin*

11.5 (8.9)

14.4 (14.3)

Marker 52

11.9 (9.3)

15.9 (16.1)

Cape Coral Bridge

18.3 (15.7)

19.5 (19.6)

Shell Point

28.8 (26.6)

29.4 (27.2)

Sanibel

31.9 (29.7)

32.8 (31.0)

*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 7.1 psu.  Salinities at the Cape Coral Bridge are within the preferred range for the oyster, Crassostrea virginicaSalinity 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, Collier and Monroe counties or offshore of the Florida Keys (Monroe County).  Three samples collected alongshore of Sarasota County (out of 28 total samples) ranged from background to very low concentrations of K. brevis.  Samples collected alongshore and offshore of Lee County ranged from not present to medium concentrations of K. brevisAn extensive fish kill in conjunction with discolored water was reported approximately ten miles offshore, southwest of Sanibel Island.

 

Monitoring data collected by the River, Estuary and Coastal Observing Network  of Sanibel-Captiva Conservation Foundation indicated that chlorophyll ranged from 1.7 – 3.4 ug/l at Fort Myers and 1.0 – 4.1 ug/l at Shell Point; DO ranged from 4.4 – 6.8 mg/l at Fort Myers and 4.2 – 6.4 mg/l at Shell Point.  Fort Myers values are from yesterday only, the recorder has been down.

 

Biscayne Bay

 

Continuous salinity measurements are now being measured at two sites in Biscayne Bay*.  Data will be reported on a monthly basis.  This initial report is not particularly detailed but will be refined in the future, as more data is accumulated.  Salinity at both sites was close to 20 ppt at the end of September, and showed a general increase for most of the last month (ranging from about 25 – 32 ppt).  Salinity at the southern station, BBCW10, is more variable than for BBCW8.  Recently, salinity has increased, most likely in response to declining rainfall.

 

Average Salinity (psu)

Sampling Site

August

September

October

BBCW8

27.1

28.6

28.6

BBCW10

33.5

27.0

28.8

 

Water Conservation Areas (WCA)

 

This week’s pan evaporation of 1.22 inches* was similar to last week’s, greatly exceeding rainfall in the conservation areas*.  Stages declined in all areas except for WCA-2B.

 

Stage Change:                   WCA-1:                 -0.08 foot            WCA-3A:              -0.15 foot

                                                WCA-2A:              -0.17 foot            WCA-3B:              -0.08 foot

                                                WCA-2B:              0.05 foot             NESRS:                  -0.07 foot

 

Water depths are declining across the region from -0.06 foot to -0.20 foot except in WCA-2B*.  Gage 65 has now dropped below 2.5 feet, a depth monitored for stress to trees on the tree islands in southern WCA-3A.  Marsh water stages in WCA-1 remain 0.5 foot below regulation in zone B.*  Stages in WCA-2A are 0.4 foot above regulation and are following the gradual decreasing slope of the regulation schedule, which is preferred going into the dry season for the wetlands.  In WCA-3A, stages have declined rapidly and are now 0.25 foot below regulation.

 

Water depths in the conservation areas show overall declines relative to a month ago*.  Greater Everglades’ depths are lower than they were a week ago, a month ago, and a year ago.*

 

Everglades National Park

 

Like the rest of the Greater Everglades, very little rain fell across Everglades National Park (ENP) wetlands and Florida Bay.  ENP stations measured 0 – 0.4 inch of rainfall.  The basin-wide totals were 0.2 and 0.01 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 0.2 and 0.5 inch, respectively.  To the south, water levels in the ENP panhandle and in Craighead Basin declined 0.8 and 1.1 inches, respectively.  Current water levels at all ENP wetland stations are considered seasonally normal.

 

Salinity* increased or remained steady across Florida Bay last week.  In the near-shore eastern Bay, salinity increased to the middle teens in Highway Creek, to the low 20s in Long Sound, and to the middle 20s at the Little Madeira Bay platform.  Salinity remains in the low 30s further into the Bay in Duck Key Basin.  The 30 day moving average salinity at the Taylor River platform (used for tracking the Florida Bay Minimum Flow and Levels) increased slightly from 0.9 psu to 1.0 psu, with the daily mean salinity remaining steady near 1 psu.  In the north central Bay, salinity increased from the middle teens to the mid 20s in McCormick Creek, and after increasing to the upper 20s, salinity settled back to the middle 20s in Terrapin Bay.  At the central Bay platform in Whipray Basin, salinity was steady in the middle to upper 30s.

To the west, in the upstream reaches of Shark River Slough, salinity remained < 1 psu.  Current station salinities are seasonally normal or slightly too moderately above normal across Florida Bay.

 

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 feet 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 10 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”, but approaching “dry” 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 and 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 continue to decrease and are nearing the “dry” 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 current estuary conditions, the District recommends discharge to the Caloosahatchee and Saint Lucie Estuaries continue to be limited to basin run-off.

 

Because conditions are nearing the “dry” band according to the 2008 LORS Release Guidance Flowchart, no Lake Okeechobee releases to the WCAs are recommended.

 

 

*  Go the FTP site for this week’s Ecological Conditions supporting documents

ftp://ftp.sfwmd.gov/pub/ecsdocs/2009_11_03.zip

 

 

 

 

CC:         George Horne