MEMORANDUM

 

TO:            Chip Merriam, Deputy Executive Director, Water Resources

 

FROM:      SFWMD Staff Environmental Advisory Team

 

DATE:       October 23, 2007

 

SUBJECT: Weekly Environmental Recommendation for Systems Operations

 

Recommendation

 

No regulatory releases to the south or estuaries are recommended.

 

Background

 

Scattered daily shower activity, increasing Wednesday and into the weekend.  Daytime heating will tap some residual moisture over the area to generated scattered showers and a couple thunderstorms today mainly over the interior and north.  A cold front moving into Florida's panhandle today is forecast to stall near Lake Okeechobee Wednesday night before returning to north Florida Thursday and Friday and then coming back south into central Florida Saturday.  Expect the front to produce moderate coverage of showers and thunderstorms each day with heaviest activity focused north.  The next ten days precipitation outlook is above average with low confidence.

 

Kissimmee Watershed

 

Over the last 7 days, the upper Kissimmee Basin received 0.68 inches of rainfall and the lower basin received 1.07 inches.  For the last week, water levels have been fairly stable in most of the upper basin lakes.  Water levels are at or below their respective regulation schedules.  Water level in Lake Toho continues to rise with inflow from Shingle Creek.  Water level in Lake Kissimmee fell approximately 0.2 ft.  The only releases being made in the upper basin are at S-65.  Snail kite nesting season on Lake Tohopekaliga has ended.

 

Flow has been reestablished to the Kissimmee River for 97 days (S-65 re-opened on 07/18/07).  Discharge at S-65 continues at approximately 500 cfs.  In the river channel of the Kissimmee River, mean daily concentrations of dissolved oxygen have been 2 mg/L to 3 mg/L.

 

Lake Okeechobee

 

According to the USACE web site, Lake Okeechobee stage is 10.22’ NGVD, which is 0.14’ higher than a week ago and 0.54’ higher than a month ago.  The current stage is 2.68’ lower than it was a year ago and remains almost 5’ below its historical average for this time of year.  Total surface inflows are 1161 cfs and include discharges through the S65E, S84, and S191 structures.  This total does not include gravity flows that might be occurring from WCA1 or through the S77 and S308 structures.  No surface outflows are reported.

 

Monthly phytoplankton monitoring was completed last week.  Six of the nine monitoring sites were sampled for nutrients and phytoplankton.  The remaining 3 sites were dry.  No algal blooms were reported.

 

An interagency workshop will be held on October 24th to plan in-lake restoration projects for implementation in conjunction with the low lake stages anticipated for this coming dry season.

 

St. Lucie Estuary

 

No releases occurred at S-80 over the past week.  Weekly average salinities at the four monitoring sites in the St. Lucie are given below in parts per thousand (ppt).

 

 

Weekly Average Salinity (ppt)

 

Sampling Site

Surface

Bottom

Envelope

Palm City Bridge (S. Fork)

2.1

2.7

 

HR1 (N. Fork)

1.1

5.0

 

Roosevelt Bridge

5.9

7.2

8.0 – 25.0

A1A Bridge

14.2

23.0

20.0 – 31.0

 

Average salinity increased throughout the estuary last week.  Only bottom water at the A1A Bridge fell within the preferred salinity range.  Based on the salinity tolerances of the oyster, Crassostrea virginica, salinity conditions in the estuary are poor to fair.

 

Caloosahatchee Estuary

 

Discharge at S-79 averaged 11.4 cfs over the past week.  The concentration of chlorides at the Olga Plant is 78 mg/l.  Average salinity increased throughout the estuary last week.  Data for specific sites are given below in parts per thousand (ppt).

 

 

Weekly Average Salinity (ppt)

Sampling Site

Surface

Bottom

Franklin Locks (S-79)

7.8

8.2

Rt. 31 Bridge

7.2

9.5

I-75 Bridge

6.6

8.9

Ft. Myers Yacht Basin

13.2

15.8

Cape Coral Bridge

19.8

23.6

Shell Point

29.0

30.4

 

Salinity conditions throughout the system are good seaward of Cape Coral.  Conditions in the upper estuary are poor.

 

FWRI reports a bloom of Karenia brevis, the Florida red tide organism, 5 to 30 miles west of Collier County.  The bloom is offshore between Wiggins Pass and southern Naples.  Additional offshore samples collected west of Pinellas, Manatee, Sarasota, Charlotte and Lee counties contained K. brevis concentrations ranging from not present to very low.  Background to very low concentrations have also been detected in alongshore samples collected in southern Lee County and northern Collier County.

 

Water Conservation Areas

 

Rainfall amounts led to fair to good re-hydration rates at all gages within the system with the exception of WCA-2A and NW WCA-3A.  The 2-17 gage in WCA-2A had a net deficit water budget (-0.06’).  The 6-2 gage in NW WCA-3 also reported a net deficit of -0.03’, but the entire WCA-3 area average showed an increase of 0.09’.  These deficits at the 2-17 and 6-2 gages have been on going for two an three weeks, respectively.  Water depths remain good for this time of year because all locations have at least 1.0 ft of water.  Stages in WCA-1 are within Zone A2.  Water levels in WCA-2A remain well above regulation.  Stages in WCA-3 are again slightly below regulation.


Everglades National Park

 

Rainfall was patchy and generally low across Everglades National Park (ENP) and Florida Bay last week.  Wetland and marine stations received between 0.1 - 0.7” of rain over the 7day period.  The weekly RAINDAR ENP spatially averaged basin-wide accumulation was on the high side of this range at 0.8” last week.  ENP wetland water levels decreased last week due to lower rainfall.  The water level (6.23’) at Shark River Slough (P33) decreased by only 0.01’ over the 7day period, but is low for this time of the year (end of the rainy season).  Stations in the south saw water level declines of 0.25’ at Taylor Slough Bridge, and 0.15’ at both the ENP panhandle (EVER6) and at Craighead Pond.

Salinity remained low and stable across Florida Bay last week.  Strong flow from the Everglades down to the Bay through both Trout Creek and Taylor River allowed salinity to remain in the single digits (with a brief mid-week reversal).  Salinity concentrations at the Little Madeira Bay mouth platform held in the low teens last week.  Salinity in the Taylor River ponds remained below 1 psu all week.  In the north-central Bay areas, Terrapin Bay salinity increased slightly into the low teens (up from single digits last week), while McCormick Creek salinity held below 10 psu over the week.  Salinity to the south, in Whipray Basin, was reading just below 30 psu for another week.  In the Shark River Slough outflow at Tarpon Bay, salinity remained very low, just below 2-3 psu over the 7 day period.

 

Water Supply

 

Water levels in the upper and lower Kissimmee Basin and Lower West Coast (LWC) showed no significant change this week although there was some continued recovery in shallow wells in the LWC and Upper East Coast this week as a result of local rainfall.  Water levels also rebounded in the coastal areas of Lower East Coast over the past week, and they are now near or slightly above their historical averages.  Surface and groundwater levels in Water Conservation Areas 1 and 2 are now near the historic averages.  Water levels in WCA 3A are still somewhat below their historic averages.  Water levels in the southern-most portion of Dade County are slightly above average historic conditions as a result of local rainfall.

 

Six out of eleven water supply risk measures are in the “high” risk category this week - the projected Lake O Stage (SSM), the Palmer Index for Tributary Conditions, the LOK Seasonal Net Inflow Forecast and Lower East Coast Service Areas 1, 2 and 3.

 

Water Conservation Areas 1, 2A and 3A continue to be in the “low” risk category.

 

The CPC Precipitation Outlook and the LOK Multi-Seasonal Net Inflow Forecast remain at “medium” risk this week

 

WSE (Lake Okeechobee Regulation Schedule)

 

The current Lake O stage – at 10.22’ today - remains in the Water Shortage Management zone and is unlikely to move back into Zone E in the next several months.

 

 

 

 

 

 

 

CC:   George Horne