Melbourne builds biggest baffle box east of Mississippi River to reduce lagoon pollution

Billed as the biggest nutrient-separating baffle box east of the Mississippi River, an underground stormwater structure will help prevent nitrogen, phosphorous and litter from contaminating the ailing Indian River Lagoon.

Crews are constructing the Cliff Creek baffle box off the river side of U.S. 1 just south of Unity of Melbourne, a bit south of Lake Washington Road

Inside the concrete-walled box, polluted stormwater runoff will enter metal screens that capture debris; storage chambers that capture sediments; and skimmers that remove nutrients.

Afterward, the treated water will flow beneath nearby Pineapple Boulevard into the river.

"It'll bring life back to the lagoon, versus where we're at now," said Larry Herald, a sales manager with Oldcastle Infrastructure, the baffle box manufacturer.

The Melbourne City Council approved the $715,290 stormwater utility project. The Save Our Indian River Lagoon ½-cent local infrastructure surtax will cover $347,781 of that sum. 

A tall yellow crane arrived Tuesday at the construction site, where workers have excavated a deep rectangular hole. Once completed, the baffle box will measure 25 feet wide, 20 feet long, and 14.5 feet deep, Melbourne Engineering Supervisor Dani Straub said.

The baffle box will serve a 515-acre drainage basin roughly bounded by Stewart Road to the west, Sweetwood Drive to the north, and downtown Eau Gallie to the south. 

Engineers project the Cliff Creek baffle box will annually remove 3,952 pounds of nitrogen and 797 pounds of phosphorus — both of which can generate harmful algal blooms.

By comparison, Melbourne officials have installed seven smaller baffle boxes the past five years that — combined — remove about 3,394 pounds of nitrogen and 829 pounds of phosphorus per year.  

Just upstream from the work zone, the Cliff Creek waters were marred Wednesday by plastic foam cups, hundreds of decomposing leaves, plastic bags and a Bud Light can.

Thick green vegetation also choked Cliff Creek — a telltale sign of high nitrogen levels, said Brent Neubauer, Oldcastle Infrastructure director of product management.

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Inside the baffle box, "Bold & Gold" pollution-control filtration media are designed to remove up to 75% of nitrogen, 95% of phosphorus and 95% of total suspended solids. Bold & Gold was developed by the University of Central Florida's Stormwater Management Academy.

Melbourne public works and utilities workers will inspect and clean out the baffle box on a maintenance schedule that will vary on rain events, said Cheryl Mall, city spokeswoman.

Straub said she hopes construction wraps up by late May. City engineers plan to install more lagoon fund-financed baffle boxes across Melbourne to combat pollution entering the river. 

City officials planned to open construction bids Wednesday for an Otter Creek baffle box serving a roughly 300-acre drainage basin encompassing Sherwood Park and surrounding neighborhoods. Otter Creek flows eastward from Sherwood Park through the Mobiland-by-the-Sea manufactured housing community into the lagoon.

Rick Neale is the South Brevard Watchdog Reporter at FLORIDA TODAY. Contact Neale at 321-242-3638 or rneale@floridatoday.com. Twitter: @RickNeale1. To subscribe: https://cm.floridatoday.com/specialoffer/