Management of Large Inflow and High Water Levels in Lake Okeechobee
Paul Trimble, Jayantha Obeysekera, Luis Cadavid, Walter Wilcox, Everett R.
Santee, Calvin Neidrauer
South Florida Water Management District, West Palm Beach, Florida
WSE, which is short for Water Supply/Environmental, is a set of new operational
guidelines for managing high water levels in Lake Okeechobee. This set of
guidelines was put into operations in July 2000. The emphasis of these guidelines
is to manage high water levels in a manner that would minimize the stresses on
the Lake littoral zone without compromising the other major objectives of the
Lake water management. Detailed analysis demonstrated that performance of the
WSE operational guidelines are equal or better than the other proposed and past
operational guidelines for meeting the objectives of flood protection, water
supply, and environmental protection and enhancement, including benefits to the
lake ecosystem and Everglades hydroperiod. The WSE guidelines incorporate
tributary hydrologic conditions, regional seasonal and multi-seasonal climate
forecasts for making operational decisions to discharge water to the Water
Conservation areas and to tidewater. These guidelines also allow for operational
flexibility for environmental enhancement and/or to minimize impacts to the
natural ecosystems affecting by the operational decisions.
The purpose of this presentation is to:
1.
Describe key features of the new WSE operational guidelines. Figure 1
illustrates the various high water zones that are defined within the WSE
operational guidelines. Zone A, B and C are similar to the operational zones of the
previous operational schedule known as ‘Run 25’. Zone D allows water
discharges at Lake levels similar to operational practices prior to the year 1978.
However, the new operational guidelines adjust the magnitude of the discharges
based on hydrologic and climatological seasonal and multi-seasonal outlooks and
the needs of the natural ecosystems affected by the discharges. Two decision trees
based on extended period climate and hydrologic outlooks are part of the WSE
operational guidelines. The first defines the range of discharges that may be made
from the Lake to the Water Conservation Areas and the second defines the ranges
of
discharges
that
would
be
made
to
the
estuaries.
Figure 1. Lake Okeechobee High Water Operational Zones
Water Level (feet)
19.00
Zone A
Zone B
18.00
Zone C
17.00
Zone D
16.00
15.00
14.00
1-Jan
1-Dec
1-Nov
1-Oct
1-Sep
1-Aug
1-Jul
1-Jun
1-May
1-Apr
1-Mar
1-Feb
1-Jan
13.00
2.
Discuss the simulated overall performance benefits of the WSE operational
guidelines compared to the previous operational guidelines known as ‘Run 25’.
Figure 2 gives an overall comparison of the performance of the new set of
operational rules.
3.
Explain the real time implementation process of the operational guidelines
including monitoring: a) the health of the natural ecosystems that are affected by
operational decisions, b) the state of the current climate and the seasonal and
multi-seasonal climate outlook, and c) the current and projected states of the
regional water levels and supplies
4. Report on the initial performance of these guidelines. The water level for Lake
Okeechobee as of January 7th, 2003 was 16.10 feet. Although this may be higher
than desirable for the Lake littoral zone, it is nearly 1 foot lower than the water
level would have been under the previous operational guidelines. Low volume
regulatory discharges began during July of the year 2002 decreasing the
magnitude of discharge that would be needed to tidewater through the estuaries
during the 2002-2003 winter months.
Figure 2. Performance Measure Summary
Operational Schedule 25 dashed format ------------Operational Schedule WSE solid format _________
Axes are designed so that larger pentagon represents a better Performance
Paul Trimble, SFWMD, 3301 Gun Club Road., W.P.B. Fl., 33406
Phone: 561-682-6509, ptrimble@sfwmd.gov