Operational recommendation

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 20, 2009

SUBJECT: Weekly Environmental Conditions for Systems Operations

Summary

Discharge from Lake Kissimmee is currently 263 cfs. Lake Okeechobee stage is 14.19 feet NGVD, which is 0.24 foot lower than a week ago, 0.33 foot lower than a month ago, 0.72 foot lower than it was a year ago, and 0.19 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 1.50 inches this week. Salinity was stable or increased across Florida Bay last 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 3^rd. Since that time, releases at S-79 and S-80 have been limited to basin runoff.

Background

Widely scattered weak, fast moving showers focused east through Thursday. The morning atmospheric profile is classic for mid to late October: strong low level northeast flow separated from westerly winds above 8000 feet by a strong subsidence inversion. Weak showers will flourish in the moist and slightly convergent low level winds. These showers could increase in coverage as flow veers to the east and mid level high pressure moves away from the peninsula Wednesday and Thursday. Shower activity should decrease Friday as flow weakens ahead of a cold front. The weak front pushes into central Florida late Saturday with some showers mainly north and east of the Lake then. The next ten days precipitation outlook is near average with low confidence.

Kissimmee Watershed

Over the past week the Upper Kissimmee Basin received 0.2 inch of rainfall and the Lower Kissimmee Basin received 0.1 inch. For the month, rainfall was 48% and 17% of normal in the Upper and Lower Basins, respectively. Total rainfall in the last 30 days was 3.3 inches in the Upper Basin (81% of normal) and 2.0 inches in the Lower Basin (52% of normal) (SFWMD Daily Rainfall Report 10/20/2009).

Lakes in the Kissimmee Chain are within 0.6 foot of their regulation schedules (USACE Kissimmee River Report 10/19/09 and/or SFWMD OASyS DualTrend or LOGGERNET). Lakes Hart and Mary Jane are 0.4 foot below regulation schedule. Lakes in the Alligator Chain are 0.6 foot below regulation schedule. Lake Gentry is 0.2 foot below regulation schedule. East Lake Tohopekaliga is 0.4 foot below regulation schedule. Lake Tohopekaliga is 0.1 foot below regulation schedule; discharge at S61 is 0 cfs.

Lakes Hatchineha and Cypress are 0.6 foot below regulation schedule. Lake Kissimmee is approximately 0.2 foot below regulation schedule. Discharge at Lake Kissimmee (S65) is 263 cfs.

In the Lower Kissimmee Basin (SFWMD OASyS Dual Trend or LOGGERNET 10/20/2009) discharge at S65-A is 252 cfs. Discharge at S65-C is 341 cfs with headwater stage at approximately 35.7 feet. Discharge at S65-D is 368 cfs. Discharge to Lake Okeechobee at S65-E is 297 cfs. Water depths continue to recede in the Phase I restoration area floodplain of the Kissimmee River, averaging 0.9 foot (SFWDAT 10/18/2009).*

River channel dissolved oxygen (DO) concentrations in the Phase I area averaged 3.8 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; a contractor will be conducting aerial treatments in the Pool BC floodplain and river channel.

Phase IVB backfilling for the Kissimmee River Restoration Project in upper Pool BC is approximately 90% finished, with completion anticipated by February 2010.

Lake Okeechobee

According to the USACE web site, Lake Okeechobee stage is 14.19 feet NGVD for the period ending at midnight October 19, 2009, which is 0.24 foot lower than a week ago, 0.33 foot lower than a month ago, and 0.72 foot lower than a year ago. The current stage is 0.87 foot below the historical average for this date and 0.19 foot above the simulated average using the current regulation schedule (LORS2008). Total reported inflows are 373 cfs and include flows through S65E (330 cfs), S84 (17 cfs), and Fisheating Creek (26 cfs). Direct rainfall on the Lake during the past week averaged 0.048 inches according to seven-day Raindar. Reported outflows are 767 cfs and include S351 (229 cfs), S352 (86 cfs), and S77 (452 cfs). No flow data are available for C5 and the L8 at Canal Point.

Monthly algal bloom monitoring was conducted at all of the nine sites on October 15th. Water clarity was good with a mean light penetration depth of 1.5 meters (same as in September) and no blooms were detected. September microcystin levels were at or below the 0.2 parts per billion detection limit at all sites sampled.

Vegetation Management staff report that Florida Fish and Wildlife Conservation Commission approved a permit for the USACE to treat up to 3,000 acres of floating exotic plants (specifically water hyacinth and water lettuce) along the western shoreline of Lake Okeechobee later this month. The goal of this treatment is to reduce the amount of floating exotics to manageable levels for contracted ground crews to maintain. The treatments will be made aerially (by helicopter) and non-mixed communities will be targeted when possible; however, some non-target damage to bulrush, cattail and other plants is expected because mats of water hyacinth and water lettuce are mixed with native vegetation in many areas. Data suggests that a single treatment of Diquat (the herbicide being used) does not cause systemic damage to bulrush and other plants so re-growth should occur.

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
Palm City Bridge (S. Fork)	13.7 (9.8)	5.1 (11.3)
HR1 (N. Fork)	16.3 (11.8)	19.4 (15.0)
Roosevelt Bridge	19.0 (15.6)	21.1 (16.8)	8.0 – 25.0
A1A Bridge	27.2 (22.6)	29.2 (26.3)	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 33 cfs at S-79, 28 cfs at S-78, and 280 cfs at S-77. The concentration of chlorides at the Olga Plant was 55 ppm yesterday. 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)	0.5 (0.2)	0.5 (0.3)
Rt. 31 Bridge	0.7 (0.3)	1.0 (0.3)
I-75 Bridge	1.2 (0.3)	2.4 (0.8)
Ft. Myers Yacht Basin	NR (NR)	NR (NR)
Marker 52	6.4 (3.7)	10.1 (8.9)
Cape Coral Bridge	14.3 (10.7)	16.0 (14.3)
Shell Point	26.0 (25.3)	26.8 (25.5)
Sanibel	30.2	31.1

Salinity increased throughout the estuary last week. Salinity conditions in the upper estuary are considered good. Salinities at the Cape Coral Bridge are within the preferred range for the oyster, Crassostrea virginica. Salinity at Shell Point indicates 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, Hillsborough, Manatee, Collier and Monroe counties or offshore of Pinellas and Monroe counties. Four samples collected alongshore of Sarasota County (out of 29 total samples) ranged from present to very low concentrations of K. brevis. Two samples collected alongshore of Charlotte County and one sample collected alongshore of Lee County contained background levels of K. brevis. A research cruise that was conducted last week through early this week offshore of southwest Florida detected levels of K. brevis ranging from background to medium concentrations offshore of Lee and Collier counties, west and south of Sanibel Island.

Monitoring data collected by the River, Estuary and Coastal Observing Network of Sanibel-Captiva Conservation Foundation indicated that chlorophyll ranged from and 1.2 – 3.4 ug/l and DO ranged from 4.0 – 6.8 mg/l at Shell Point. Reading at Fort Myers were unavailable.

Water Conservation Areas (WCA)

This week’s high pan evaporation of 1.50 inches* led to stage declines throughout the Greater Everglades in patterns more typical of winter than of the wet season.*

Stage Change: WCA-1: -0.12 foot WCA-3A: -0.21 foot

WCA-2A: -0.22 foot WCA-3B: -0.06 foot

WCA-2B: -0.06 foot NESRS: -0.03 foot

Water depths are dropping region-wide *. The EDEN 13 gage in WCA-2B has dropped below 2.5 feet, so the only gage in areas with remaining tree islands that still exceeds 2.5 feet (relevant to tree island inundation duration) is gage 65 in southern WCA-3A. Marsh water stages in WCA-1 are well below regulation in zone B. Stages in WCA-2A remain above regulation, but are declining. In WCA-3A, stages have re-entered the upper transition zone after weeks of exceeding this zone but are declining rapidly.*

Water depths in the conservation areas are lower than they were a month ago*, and increased areas of subsurface water in Everglades National Park (ENP) and the Holeyland WMA. Greater Everglades depths are lower now than they were a week ago, a month ago, and a year ago.*

Everglades National Park

Light rain fell across ENP wetlands and Florida Bay (Bay) last week with ENP stations measuring 0 – 0.9 inches of rainfall. The basin-wide, spatially-averaged totals were 0.2 and 0.3 inch for the ENP and C-111 basins, respectively.*

Stages declined across ENP wetland stations last week.* Stages in Shark River Slough and at the Taylor Slough Bridge declined 0.5 and 1.0 inch, respectively. To the south, water levels in the ENP panhandle and in Craighead Basin declined 1.7 and 1.3 inches, respectively.

Salinity was stable or increased across Florida Bay last week.* In the near-shore eastern Bay, salinity increased to the middle teens in Long Sound and remained in the low 20s at the Little Madeira Bay platform. Salinity remained in the low 30s further into the Bay in Duck Key Basin. The 30 day moving average salinity at the Taylor River platform rose from 0.7 psu to 0.8 psu, with the daily mean salinity increasing to a more saline 4.4 psu. In the north central Bay, salinity spiked mid-week but by the end of the week returned to the low teens in McCormick Creek and low 20s in Terrapin Bay. At Whipray Basin, salinity remained in the upper 30s. To the west, salinity in the upstream reaches of Shark River Slough increased slightly to 2 psu.

Water Supply

Groundwater levels across the District are slowly declining with the arrival of the dry season. 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 wells in Polk and western Orange counties that have dropped into the lowest 30^th 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, particularly in far northern Palm Beach County. In the Lower East Coast, groundwater levels in the United States Geological Survey (USGS) network are at median values or higher for most wells. There are a few wells in Miami-Dade County near a rock mining operation south of US 41 near Krome Avenue that have dropped to the lowest 10^th 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.

About half of the Sandstone aquifer wells in the USGS network are in the median range and the rest are in the lowest 10^th to 30^th percentile range. Mid-Hawthorn wells are mostly at median values for this time of year in Lee County and in the lower 10^th to 30^th percentile range 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 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 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 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_20.zip