LWI Region 3 Modeling Overview

Each station was linked to a storage sump and included operational logic such as pump start/stop triggers based on interior and exterior water levels. The Rochelle Avenue station alone accounted for ~60,000 gallons per minute (GPM) of pumping capacity. Table 3-2 summarizes the pump station specifications used in the model, including flow capacities and horsepower extracted from as-built documents and GIS records. Figure 3-21 depicts the locations of these pump stations. These parameters were critical in accurately representing pump operations during storm events and were used throughout model setup and calibration.

Table 3-2 City of Monroe pump station specifications used in the model, including flow capacities and horsepower extracted from as-built documents and GIS records.

PUMP STATION NAME

ADDRESS

UNITS

HORSEPOWER

FLOW (GPM)

901 Stubbs Avenue

2

350

30000 60000

Stubbs

901 Rochelle Avenue 3

1250 HP (Diesel)

Rochelle Ave

2151 Island Drive 2003 Lamy Lane

2 3

Pump 1: 150

Pump 1: 20,000

N 10th Street W

350

35000

Lamy Lane

Pump 1&2: 60,000

Pump 1&2: 500 HP (Electric) Pump 3: 625 HP (Diesel)

2505 Oliver Road

3

Pope Westminster

Pump 3: 80,000

7 Olive Street

4 3

400 200

50000 27000

PineSt

518 Oregon Trail

OregonTrail

2708 Hawes Street

1

600

60000

Hawes St

Pump 1: 30 Pump 2: 60 Pump3: Diesel

Pump 1: 1,600 Pump 2: 7,000 Pump3: 15,000

220 Plum Street

3

Plum St

110 Allen Ave

2

200

15000

Allen Ave

Pump 1: 150 Pump 2: 200

Pump 1: 20,000 Pump 2: 35,000

Pump1_P1 - MarquetteSt

2151 Island Drive

2

Boundary Conditions { Upstream boundaries were applied using hydrographs derived from the HEC-HMS model, ensuring accurate inflow from hydrologic sources in Arkansas and neighboring basins. { Downstream stage boundaries were based on observed stage hydrographs at the Ouachita River (e.g., Columbia L&D, Harrisonburg, West Monroe), allowing propagation of backwater effects into the Boeuf system. For higher stages of the Ouachita River, a series of gates along the levee system (shown in Figure 3-21 ) close, preventing backwater from entering the City of Monroe. Figure 3-21 shows the applied boundary conditions. { Lateral inflows were added during calibration to simulate spill over from adjacent basins, particularly from Bayou Bartholomew in extreme events like March 2016. { Former internal boundaries between model groups (e.g., BF-West, BF-South) were replaced with seamless 2D mesh connectivity to ensure mass continuity.

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Hydrologic and Hydraulic Modeling Methodology