Specifications

Section 6 The Selected Alternative Plan
EAA Storage Reservoirs Revised Draft PIR and EIS February 2006
6-26
During design development, the discharge arrangement will be selected based on
a life cycle cost analysis of the operational and construction costs.
6.4.3.2.4 Large-Sized Pumping Stations
G-370 and G-372 are already existing large-sized pumping stations located
adjacent to the Project. SFWMD constructed G-370 and G-372 within the last
five years to provide restoration water for STA-3/4. G-370 is located along the
North New River Canal and has three 925 cfs diesel driven pumps, with a design
capacity of 2775 cfs. G-372 is located along the Miami Canal and has four 925
cfs diesel driven pumps, with a design capacity of 3700 cfs.
In addition, both G-370 and G-372 have three small 75 cfs electric motor driven
pumps included in their design for seepage control, and these six existing 75 cfs
pumps will continue to be used for STA-3/4 control seepage. EAA project seepage
control requirements will be met with the new medium-sized pumping stations.
Modifications needed in order to use the large pumps of G-370 and G-372 to fill
the EAA reservoir are discussed and described below.
6.4.3.2.5 Pumping Station Modifications – General
G-370 and G-372 need to be modified to pump water to fill the EAA reservoir to
a maximum water depth of 12 feet, because this is so much more than what
these pumping stations were originally designed to do, which is pump water to
fill STA-3/4 at a maximum water depth of 5 feet.
The prevailing EAA project area ground level is 10 feet NGVD, while the
maximum water level of STA-3/4 is 15 feet NGVD, and maximum pumped level
of the EAA reservoir is 22 feet NGVD. In addition, G-370 will need to be able to
pump to an elevation of 23 feet NGVD, since its output will flow into discharge
impoundment from which gated culverts will direct water to either STA-3/4 or
the EAA reservoir.
The amount of pump flow or capacity depends on two basic components: The
design of the pump and the amount of power available from the engine. Because
flow is a result of the relationship between the available horsepower and the
amount of head, as well as the design of the pump and its efficiency, if the pump
could still operate at the increased head with the same available horsepower, the
flow for each pump would drop. The reduction in flow is also tied into the design
of the pump and the impeller, and in order to keep the system on the pump’s
operational curve, additional horsepower will be required even with a reduction
in flow.