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: April
7, 2009
SUBJECT: Weekly
Environmental Conditions for Systems Operations
Summary
Discharge from
The declining water levels
are again reflected this week in areas of the Water Conservation Areas (WCA) and
Everglades National Park (ENP). Wading
bird feeding conditions are good in most of WCA-1, WCA-2B, middle WCA-3A, and
southern WCA-3B, but water levels are below ground in WCA-2A, northern WCA-3A,
and in ENP. Groundwater levels continue
the current downward trend across most of the District.
Background
Still
cooler Wednesday night; some showers this weekend. A cold front has pushed through the District
and dry conditions have spread across the area with cooler temperatures
expected through Thursday morning.
Southeasterly winds will moderate temperatures Thursday and Friday and
allow some spotty showers to pop up mainly southeast each day. The next cold front is expected to move into
central
Over the last
seven days, the upper Kissimmee Basin received 0.57 inches of rainfall and the
lower Kissimmee Basin received 1.08 inches of (Daily Rainfall Report 4/03/09).
Stage in Lakes
Kissimmee, Hatchineha and
Lakes Tohopekaliga and
Stage in
Hydrilla treatments are scheduled for Lakes Kissimmee, Hatchineha and Jackson on 4/14/09 through 4/16/09.
According to the survey maps
from 3/26/09, there are approximately 23 active nests on
Discharge from
A turbidity plume
in lower Pool C was observed over the weekend.
The plume is likely a result of establishment of flow through the newly
constructed section of river channel and turbidity is expected to dissipate in
a short amount of time.
Over the last
seven days, dissolved oxygen (DO) concentrations in the
According to the United
States Army Corps of Engineers (USACE) web site,
The routine aerial wading
bird survey of the lake’s littoral zone was conducted on Wednesday March 25,
2009 by
Great Egrets chicks are now
hatching and the smaller herons are now laying eggs. White Ibis and Glossy Ibis
are now building nests, mostly in cattails. The colony in northern Indian
Prairie has also increased in size with more nesting by Snowy Egrets and Tricolored Herons. 10 Roseate Spoonbills are nesting
in the colony, with nest building activity confirmed on ground visits.
In total, eight colonies were
detected. Only four, however, were in
the traditional littoral zone. The others were at the gator farm, one at
Lakeport, and two were on Clewiston Spit.
Although this year's nesting is considerably higher than the previous
two years, it is not likely to be close to the outstanding year of 2006,
probably because so much of the marsh is already dry.
Monday, April 6, 2009
District crews saw 30-40 egg masses of the native
Saint Lucie Estuary
Over the past week discharge
averaged 0 cfs at
S-80. Discharge from the
|
Weekly Average Salinity
(ppt) |
|
|
Sampling Site |
Surface |
Bottom |
Envelope |
|
20.3 (20.4) |
21.3 (21.4) |
|
HR1 (N. Fork) |
23.2 (24.1)
|
|
|
|
25.8 (25.9) |
26.1 (26.2) |
8.0 – 25.0 |
A1A Bridge |
30.3 (31.1) |
31.7 (32.5) |
20.0 – 31.0 |
Salinity remained about the
same throughout the estuary last week. At both the Roosevelt and A1A
Bridges weekly average salinity is above the upper bound of the preferred
range. Salinity conditions in the estuary are considered to be fair based
on the time of year and salinity preference of the oyster, Crassostrea
virginica, and location in the estuary.
Caloosahatchee Estuary
During the last week,
discharge averaged 251 cfs
at S-79, 300 cfs at S-78, and 578 cfs
at S-77. The concentration of chlorides at the Olga Plant was 145 ppm yesterday. 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 |
|
5.5 (10.3) |
6.2 (11.2) |
Rt. 31 Bridge |
7.5 (12.0) |
9.0 (13.0) |
I-75 Bridge |
9.4 (13.6) |
13.0 (15.4) |
|
18.6 (20.0) |
19.0 (20.0) |
|
26.3 (27.0) |
27.0 (27.6) |
Shell Point |
34.3 (34.0) |
35.2 (35.8) |
A seven-day pulse release at
S-79 ended on Saturday, 4/4/09. While average salinity declined
throughout most of the estuary, the greatest decreases occurred in the narrow
head waters of the estuary between I-75 and S-79. Conditions in the upper
estuary east of
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 DO concentration at Fort Myers (Shell
Point was unavailable) ranged from 5.3 to 9.9 mg/L
Water Conservation
Areas
Recession rates have
increased again, declining at rates considered good or fair throughout the WCAs. WCA-2A and
Northeast Shark River Slough are experiencing especially high recession rates,
-0.31 and -0.33 foot, respectively, in one week:
Stage Change: WCA-1: -0.11 foot WCA-3A: -
0.10 foot
WCA-2A: -0.31 foot WCA-3B: - 0.11 foot
WCA-2B: -0.17 foot NESRS: - 0.33 foot
WCA-1 is still
below its regulation schedule (about -0.2 foot).
WCA-2A canal stage (used from February to May) has fallen again to about -0.21
foot below schedule. The WCA-3A marsh is below about -0.5 foot the bottom
of Zone E1.
The declining water levels
are again reflected in this week’s water depths map. Large portions of WCA-1, WCA-2B, and WCA-3A
are wet, but most of the rest of the Greater Everglades are dry. Subsurface water depths continue to drop in
the WCAs, Holeyland, Rotenberger, and in the Everglades National Park (ENP),
which has large areas with water levels once again below -2.5 feet (as it was a
month ago). The drying front continues to head southward through northern
WCA-3A, and nearly all of WCA-2A is dry. The northern Refuge is now dry,
and nearly the entire ENP except the coast is dry. Water tables in Big
Cypress Preserve have continued to dry; areas that are below -2.5 feet have
expanded substantially from a month ago.
Wading bird feeding
conditions are good in most of WCA-1, WCA-2B, middle WCA-3A, and southern
WCA-3B, but water levels are below ground in WCA-2A, northern WCA-3A, and in
ENP. Recession rates are increasing with the higher evapotranspiration
rates that are typical of this time of year.
The muck fire index indicates
that most of the Greater Everglades are still in the low to moderate risk
categories, except for parts of Holeyland, Rotenberger, WCA-2A, and a small portion of ENP
Only trace amounts of rain
fell across ENP and
Stages continued to decline
last week. Water level at the
Salinity remained steady or
increased in
Water Supply
Groundwater levels continue
the current downward trend across most of the District (with the exception of
Water supply outlook: The
only remaining water supply risk indicators in the “low” risk category are
Water Conservation Areas 1 and 3A. The
projected LOK Stage for the next two months, 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 1 has moved back to “low” risk category due
to levels at 1-8C being above Line 1 (15.38 feet). As a result of recent rains, the water supply
risk indicator for the entire LEC is now in the “yellow” risk category. Water
Conservation Area 2A is in the “high” risk category, with headwater elevation
at S11B below Line 2 (10.52 feet).
LORS2008 (
Stages in
On Thursday, March 12,
District staff briefed the Governing Board on the hydrologic needs and the
ecological status of the entire system. At
that time, the Board did not request the Corps make additional environmental
water supply releases to the Caloosahatchee Estuary. Since then, the eastern portion of the
District has received additional rainfall.
This represents new information that was not available at the March 12
Board discussion. All the new additional
information has been made available to the USACE to assist in their
decision-making.
CC: George Horne
Under Construction!