M E M O R A N D U M

 

TO:                 Chip Merriam, Deputy Executive Director, Water Resources

 

FROM:            SFWMD Staff Environmental Advisory Team

 

DATE:                        January 27, 2009

 

SUBJECT:     Weekly Environmental Conditions for Systems Operations

 

Summary

 

Discharge from Lake Kissimmee is approximately 324 cfs and discharge at S65C is 362 cfs. The floodplain of the Kissimmee River is essentially dry except in the extreme southern end of Pool B/C.  Lake Okeechobee stage is 13.47 feet NGVD, which is 0.17 foot lower than a week ago, 0.58 foot lower than a month ago, 3.37 feet higher than it was a year ago, and 0.09 foot lower then the simulated average using the current regulations schedule.  Salinity conditions in the St. Lucie Estuary are considered to be good based on the salinity preference of the oyster, Crassostrea virginica.  In the Caloosahatchee Estuary, salinity conditions are good in the upper estuary, good in San Carlos Bay and good in the lower estuary.  Water levels in all three Water Conservation Areas continue to decline slowly.  Salinity values remained steady across Florida Bay.  Groundwater levels are declining due to the lack of rainfall, but most of the water supply indicators remain in the low risk category.

 

On December 15, 2008, the United States Army Corps of Engineers (USACE) discontinued base flows to the Saint Lucie estuary and increased flows to the Caloosahatchee Estuary to 650 cfs.  Monday the USACE completed a seven day pulse release to the Caloosahatchee Estuary that averaged 650 cfs over the seven days.  Wednesdayday, the USACE will initiate another seven day pulse release to the Caloosahatchee Estuary that will also average 650 cfs per day.

 

Background

 

Warmer Tuesday and Wednesday; showers Thursday and Friday.  Southeasterly and southwesterly winds are bringing warmer temperatures and a return of moisture to the area.  Expect some spotty to widely scattered showers to pop up southeast Tuesday and then north and east Wednesday.  A cold front is forecast to move into the District during the day Thursday and then weaken near Lake Okeechobee Thursday night.  An impulse moving along the frontal boundary should give it a second push through the remainder of the District during the day Friday.  Expect scattered showers and some thunderstorms to accompany the front as it moves through the northern half of the District Thursday and Thursday night with more widespread and locally heavy shower activity over the southern half of the District Friday afternoon and evening.  Cool and dry conditions are expected behind the front with temperatures near freezing over portions of the Kissimmee Valley Saturday morning.  The next ten days precipitation outlook is below average with moderate confidence.

 

Kissimmee Watershed

 

Over the last seven days, the upper Kissimmee Basin received 0.09 inches of rainfall to bring the 30 day total to 0.42 inches (18% of average) and the lower Kissimmee Basin received 0.05 inches of rain to bring the 30 day total to 0.31inches (17% of average).

 

Stage in Lakes Kissimmee, Hatchineha and Cypress is 1.8 feet below regulation schedule and stage in Lakes Tohopekaliga and East Tohopekaliga is 0.6 foot below regulation schedule.

 

On January 27, 2009 the District in collaboration with the Florida Fish and Wildlife Conservation Commission treated the final 200 acres of a targeted 7,181 acres of hydrilla in Lake Toho.  This treatment started on December 15, 2008, and after a break for the holidays, resumed in early January.  The herbicide used for this treatment was applied aerially due to the massive areas of the lake that had to be covered.  Aquathol, a widely used aquatic herbicide was used in liquid and pellet formulations to maximize its effectiveness on hydrilla.  Prior to December 15th approximately 14,000 acres of hydrilla was present in the lake.

 

Snail kite courtship and nesting behaviors are beginning to be observed around Lake Toho.

 

Discharge from Lake Kissimmee is approximately 324 cfs and discharge at S65C is 362 cfs.

 

The dry season drawdown of the Pool B/C area is on track to reach a low stage target of 33 feet on or around May 15th 2009.

 

Dissolved oxygen concentrations in the Kissimmee River are well above levels of concern.

 

Lake Okeechobee

 

According to the USACE web site, Lake Okeechobee (lake) stage is 13.47 feet NGVD, which is 0.17 foot lower than a week ago, 0.58 foot lower than a month ago, and 3.37 feet higher than it was a year ago.  The current stage is 1.22 feet below the historical average for this date and 0.09 foot below the simulated average using the current regulation schedule (LORS2008).  Total reported inflows are 370 cfs and are limited to flows through S65E.  Total reported outflows are 1095 cfs and include environmental releases to the Caloosahatchee River (285 cfs), water-supply releases through the S351, S352, and S354 (810 cfs).  Flow data to the L8 at Canal Point and through the S308 are missing.

 

A small (approx. 3 acres in size) population of the invasive old world climbing fern (Lygodium microphyllum) has been reported growing in the littoral zone near Moore Haven.  This is the first report of this species on the lake, and dry conditions in recent years likely facilitated its establishment.  Ground crews are treating the infestation, which is expected to be eradicated with repeated treatments.  This same crew is treating other invasive plants, including scattered Melaleuca and Brazilian Pepper, throughout the littoral zone.

 

An interagency meeting was held last Friday to begin developing a fire management program for Lake Okeechobee. Representatives from Distric,Florida Fish and Wildlife Conservation Commission (FFWC), Division of Forestry (DOF), and Audubon of Florida were in attendance.  The objective of the plan is to identify environmentally beneficial methods and frequencies for conducting controlled burns in the lake littoral zone and the means of implementing such a program.  A draft plan is expected to be available this spring.

 

Saint Lucie Estuary

 

Over the past week discharge averaged 0 cfs at S-80.  Discharge from the Lake at S-308 averaged 74 cfs.  Provisional data indicated that no discharge occurred at S-97 on C-23, or at S-49 on C-24.  The current weekly average salinities (in bold) at the four monitoring sites in the Saint Lucie are given below in parts per thousand (ppt), along with the previous week’s (in parenthesis).


 

 

Weekly Average Salinity (ppt)

 

Sampling Site

Surface

Bottom

Envelope

Palm City Bridge (S. Fork)

11.8 (12.2)

14.5 (14.0)

 

HR1 (N. Fork)

20.1 (NR)

23.0 (NR)4-day average

 

Roosevelt Bridge

22.0 (21.7)

22.2 (22.1)

8.0 – 25.0

A1A Bridge

27.7 (29.6)

29.0 (30.6)

20.0 – 31.0

 

Salinity changed slightly during the past week.  At the Roosevelt Bridge and A1A Bridge salinity is within the preferred range.  Salinity conditions in the estuary are considered to be good based on the salinity preference of the oyster, Crassostrea virginica, and location in the estuary.

 

Caloosahatchee Estuary

 

During the last week, discharge averaged 667 cfs at S-79, 585 cfs at S-78, and 952 cfs at S-77.  The concentration of chlorides at the Olga Plant was 63 ppm  on Monday, January 26th.  The current weekly average salinities (in bold) at the six monitoring sites in the Caloosahatchee Estuary are given below in parts per thousand (ppt), along with the previous week’s (in parenthesis).

 

 

Weekly Average Salinity (ppt)

Sampling Site

Surface

Bottom

Franklin Locks (S-79)

1.7 (2.5)

1.8 (2.5)

Rt. 31 Bridge

1.7 (3.1)

2.5 (3.1)

I-75 Bridge

2.3 (3.6)

4.6 (4.9)

Ft. Myers Yacht Basin

7.1 (8.6)

11.8 (10.4)

Cape Coral Bridge

17.2 (18.6)

19.8 (19.1)

Shell Point

27.3 (26.6)

29.1 (28.8)

 

Salinity declined in the upper estuary over the past week.  Conditions in the upper estuary east of Fort Myers are good (30 day average at Fort Myers equals 9.9 ppt).  Salinities at the Cape Coral Bridge are within the preferred range for the oyster, Crassostrea virginica, and well within the range tolerated by seagrass, Halodule wrightii.  Therefore, conditions in the lower estuary are good.   Salinity at Shell Point indicates that conditions are good in San Carlos Bay.

 

Fish and Wildlife Research Institute (FWRI) reports that water samples collected alongshore between Pinellas and Monroe counties contained no K. brevis.  Monitoring data collected by the River, Estuary and Coastal Observing Network (RECON) of Sanibel-Captiva Conservation Foundation (SCCF) indicated that over the last week Chlorophyll concentrations ranged between 4 and 13 µg/L at Fort Myers and 2 to 23 µg/L at Shell Point.  The dissolved oxygen (DO) concentration at the two locations ranged from 6.9 to 9.6 mg/L.

 

Water Conservation Areas

 

Recession rates were generally good for wading birds over the past week (although only fair in 3B).  Depths are still a little high for optimal foraging in most except for Everglades National Park (ENP) and 2A, but the high water levels and good recession rates are just what are needed at this time of year.

 

These good foraging conditions are reflected in the early nesting of fairly large numbers of storks in ENP this year.

 

Average weekly basin stage declines were:

 

Stage Change:            WCA-1:           - 0.10 foot        WCA-3A:         - 0.09 foot

WCA-2A:         - 0.08 foot        WCA-3B:         - 0.05 foot

WCA-2B:         - 0.18 foot        NESRS:          - 0.10 foot

 

Depths at gauges range from 0.32 foot in WCA-2A to 3.37 foot in WCA-2B, but most gauges report depths of one foot to about one and a half feet.

 

Continuing recent trends, WCAs 1 and 3 remain slightly below the Regulation Schedule, while WCA-2 marsh is above regulation.

 

Everglades National Park

 

Stages continued to decline in ENP last week.   Water levels in Shark River Slough and at the Taylor Slough Bridge dropped by 1.2 inches  and 5.8 inches, respectively.  Following the first full week of no flow through S-332D, water level is now below the wetland surface at the Taylor Slough Bridge.  To the south, water levels in the ENP panhandle (EVER6) and Craighead Pond dropped by 1.2 inches and 0.7 inch, respectively.

 

Salinity was stable or increased slightly in Florida Bay last week.  In the eastern Bay, salinity was steady in the mid 20s nearshore (Long Sound and Little Madeira Bay platform) and low 30s further into the Bay (Duck Key).  The 30 day moving average salinity at the Taylor River platform (used for tracking the Florida Bay MFL) dropped slightly from 1.4 psu (1/18) to 1.3 psu (1/25).  In the northcentral Florida Bay, an early week reversal increased salinity from the upper teens to the mid 20s before settling back into the low-mid 20s in Terrapin Bay and McCormick Creek.  At the central Bay platform in Whipray Basin, salinity was steady in the mid-upper 30s.  ENP staff confirmed an electrical problem has been occurring at station TE.  A technician visited the station on 1/21, and data was transmitting until 1900 on 1/22 before going off-line again.  A technician is working on getting this station back on-line Tuesday.  There was enough data to permit reporting a daily mean salinity value of 2.3 psu for the upper reaches of Shark River Slough on 1/22.

 

Water Supply

 

Groundwater levels across the District continue to decline.  Many wells in the Kissimmee Basin have water levels in the lowest 10% of their recorded past elevations, according to United States Geological Survey (USGS) records.  Comparing current water levels to past drought criteria from 2007, however, shows the elevations to be reasonable for this time of year.  Surficial aquifer levels in the Upper East Coast area are in seasonal decline with near median levels, with the exception of well STL-125, which dropped to within its lowest 10% level.  Water levels in the coastal portion of the Lower East Coast, particularly in the Dania Beach, Hallandale, and North Miami areas are low for this time of the dry season.  Groundwater levels in wells in western Miami-Dade County are average for this time of year and are declining.  In the Lower West Coast area, groundwater wells are showing average seasonal declines in water levels in the Surficial, Lower Tamiami and Mid-Hawthorn aquifers.  Some Sandstone aquifer wells are in the lowest 10- 30% range of past elevations.

 

Water supply risk indicators are in the “low” risk category including the projected LOK Stage, the Water Conservation Areas 1 and 3A, and LEC Service Areas 1, 2, and 3 (no restrictions).

 

The CPC Precipitation Outlook, the LOK Seasonal Net Inflow Forecast, the LOK Multi-Seasonal Net Inflow Forecast, and the Palmer Index for LOK Tributary Conditions continue in the “medium” risk category.  Water Conservation Area 2A has moved into the “high” risk category due to station 2-17 dropping below an elevation of 11.5 feet.

 

LORS2008 (Lake Okeechobee Regulation Schedule)

 

Stages in Lake Okeechobee are now within the base flow sub-band.  Tributary inflows are currently in the dry category.  The seasonal outlook for net inflow into the lake is for dry conditions.  The LORSS recommended discharges are up to 450 cfs at S-79 and up to 200 cfs at S-80, and no discharges to the water conservation areas.

 

On December 15, 2008, USACE discontinued base flows to the St. Lucie Estuary and increased flows to the Caloosahatchee Estuary to 650 cfs.  Monday the USACE completed a seven day pulse release to the Caloosahatchee Estuary that averaged 650 cfs over the seven day period.  The District recommends that the USACE initiate another seven day 650 pulse release to the Caloosahatchee Estuary Wednesday.

 

 

 

 

 

 

 

 

CC:      George Horne