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: August
7, 2007
SUBJECT: Weekly
Environmental Recommendation for Systems Operations
Recommendation
No regulatory releases to the south or estuaries are recommended.
Background
Afternoon
storms mainly west. Deep easterly winds
have returned to the peninsula.
Easterlies guide the east coast seabreeze
steadily westward where it can collide with the west coast seabreeze. This scenario should dominate through
Thursday afternoon. The relatively
undisturbed upper level pattern should translate into below average rainfall
with a focus west each afternoon.
Changes begin Thursday night and Friday when a tropical wave moves through
the peninsula. Rains may increase, but
these features are often over-hyped with respect to rain production. The next ten days precipitation outlook is near
average with low confidence.
The upper Kissimmee Basin received 2.31
inches of rainfall over the last 7 days to bring the 30-day total to 8.51
inches (127% of average) and the lower basin received 2.33 inches to bring the
total for the month to 8.40 inches (136% of average) (Daily Rainfall Report for
08/06/07).
Stages in the upper basin lakes continue to rise
with several of the lakes reaching regulation schedule (
Releases are being made from
Snail kites continue to nest on
Flow has been reestablished to the
After dropping to very low levels last week, the
concentration of dissolved oxygen in the river channel has increased in the
last week but remains below thresholds of concern. At one location, values have risen but are
still below 1 mg/L, where a fish kill may occur. At the other, concentrations have risen above
1 mg/L but are still below 2 mg/L, where fish may begin to become stressed. Water levels should allow fish access to the
floodplain.
On Friday August 3, 2007, an algal
bloom was reported covering most of Persimmon Mound Run (a remnant river
channel in Pool A of the
According to the USACE
web site,
This week we began our annual Submerged Aquatic Vegetation (SAV) mapping effort.
The entire submerged plant community of the lake is mapped with an
intensive program that includes over 700 sites around the shoreline. The abundance of SAV
at each site (center of each grid cell) is documented and the total number of
acres of each dominant plant species is determined and coverage maps are
developed.
An increase in algal bloom formations is anticipated as nutrient
rich runoff increases with increased rainfall.
St. Lucie Estuary
No releases occurred at S-80 over the past week,
and an average of 919 cfs flowed into
Caloosahatchee Estuary
The estimated weekly average discharge at S-79 was
down about 290 cfs from last week to 83 cfs, with no flow occurring during the previous 4
days. The monthly average discharge from
S-79 was 237 cfs, which is below the MFL target of 300 cfs and the
preferred minimum level of 450 cfs. Average flow for 24 of the previous 30 days
from C-43 to
Chloride concentration at the Olga Plant did not
change appreciably during the last week and is presently 86 mg/l. Average surface salinity was down about 2 ppt in the upper estuary, ranging from 4 ppt at S-79 to 4.8 ppt at the I-75
Bridge sensor. Bottom salinities ranged
from 4.2 ppt at S-79 to 7.2, respectively. The salinity sensor at
Access to the FWRI weekly
summary of the
Water Conservation Areas
Rainfall exceeded evaporation for most regions and
this resulted in net increases in water depth for all regions with the
exception of WCA-3B (-0.06’). Marsh depths now range between 0.62 ft (6-3
gage) and 1.56 ft. (6-5 gage) (Note: Gage 99 is not considered a marsh gauge.),
and continued increases are seen a good thing for the environment. In terms of the Regulations Schedules; WCA-1 is at Regulation, WCA-2A is
above Regulation, and WCA-3A is below regulation.
No data was received from Everglades National Park
(ENP) since last Tuesday. We are using USGS
& SFWMD data to provide an update for conditions in this area and will try
to resolve data issues from ENP by next week. Overall ENP
experienced a net loss of water depth of -0.12’. Salinity continues to remain seasonably low
& stable across FL Bay. Trout Ck. represented
the 1 exception, having experienced a mid-week flow reversal that pushed FL Bay
water northward and increased salinity concentration in the creek upwards of 20
psu before dropping to a seasonal level (~ 5 psu) over the weekend.
Salinity at the mouth of
Water Supply
Water levels in the Lower West Coast (LWC) continue to remain near low levels for their periods
of record, although water levels generally increased in the LWC
over the past week. Water levels
declined slightly in the coastal areas of the Upper East Coast and
Four out of eleven water supply risk measures are
in the “high” risk category this week including the projected Lake O Stage (SSM), 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 Palmer
Index for Tributary Conditions remains at medium risk. The LOK
Multi-Seasonal Net Inflow Forecast decreased from high to medium risk this
week. The CPC Precipitation Outlook
remained at “low” risk this week, along with the LOK
Seasonal Net Inflow forecast.
WSE
(
The current
CC: George
Horne