How a lagoon gets fixed.

The framing.

People sometimes ask why a decade of tax money has not “fixed” the lagoon — as if the water is a broken appliance and someone forgot to schedule the repair. That is not what environmental restoration looks like. The lagoon has been accumulating nutrient pollution for the better part of a century. Reversing that took the same kind of patient, engineered, multi-year infrastructure work that fixes a city’s water supply, a state’s highway system, or a country’s power grid.

Four categories carry most of the load. All four are boring. All four are expensive. All four are permitted, engineered, competitively bid, built, and monitored by people whose day job is doing this correctly. None of them is glamorous. Every one of them is measured in pounds of nitrogen prevented from reaching the water, or acres of habitat restored. The county’s full project plan also funds wastewater plant upgrades, sewer lateral repair, harvesting projects, shellfish restoration, and other categories that do not fit neatly into the four below.

1. Septic-to-sewer conversions.

Roughly 100,000 septic tanks were operating in the lagoon watershed at the peak. In sandy, high-water-table soil (which is most of the barrier island and much of the mainland), conventional septic tanks are not designed to remove nitrogen — their effluent seeps into shallow groundwater, and in Brevard’s coastal geology that groundwater ultimately reaches the lagoon on time scales that vary widely by location, but are short enough that septic loading shows up in the lagoon’s nitrogen budget every year.

A septic-to-sewer conversion means: extending the municipal sewer main to a neighborhood that was previously on septic, then physically decommissioning each septic tank and connecting the house to the sewer. The wastewater then goes to a treatment plant designed to remove nitrogen and phosphorus before discharge (usually to a reclaimed-water system, not the lagoon).

Per household, this costs the county roughly $10,000–$20,000 in mainline extension and per-parcel hookup work — and the homeowner typically pays a much smaller assessed connection fee, spread over years. It is one of the most cost-effective per-pound nutrient reductions Brevard can buy: a single mid-sized conversion project (a few hundred homes) can prevent tens of thousands of pounds of nitrogen per year from reaching the lagoon.

2. Muck dredging.

Decades of runoff, before anyone was measuring, built up a thick layer of nutrient-rich sediment (“muck”) on the lagoon bottom — in some canals and coves, three to six feet deep. Muck is not just aesthetically bad. It is a chemical reservoir: even when new pollutant inputs stop, muck continues to leak nitrogen and phosphorus into the water column for years, driving future algae blooms and preventing seagrass from re-establishing.

Muck dredging means: physically removing the accumulated sediment using specialized hydraulic dredges, dewatering it (often at a spoil site upland), and hauling it off. Depending on the site, the resulting depression can fill back in with cleaner sediment over time and support the eventual re-establishment of seagrass; outcomes vary by location and by whether upstream nutrient sources have also been reduced.

Grand Canal in Satellite Beach, Sykes Creek, Cocoa Beach’s Buccaneer Cove, Cocoa’s Cape Canaveral Barge Canal — every one of these has been through muck dredging under the SOIRL program. Muck dredging is expensive per acre but pays back in decades of avoided future pollution and in accelerated seagrass recovery.

3. Stormwater retrofits.

Most of Brevard’s stormwater infrastructure was built in the 1960s and 1970s, before anyone was measuring how much pollution stormwater carries. It sends untreated runoff straight from streets, parking lots, roofs, and lawns to the lagoon. A stormwater retrofit means: intercepting that runoff before it reaches the lagoon, and treating it — usually by routing it through an engineered treatment pond, a bioswale, a filtration vault, or a wet detention basin that lets particles settle out and plants take up nutrients before the cleaner water is discharged.

Every major SOIRL stormwater retrofit has a nitrogen-removal number attached to it. A single well-sited stormwater treatment pond can prevent thousands of pounds of nitrogen per year from reaching the lagoon — and it also reduces localized flooding, which is a hidden bonus for the neighborhoods it protects.

4. Living shorelines and habitat restoration.

A living shoreline is what it sounds like: instead of a hard concrete seawall (which reflects wave energy, provides no habitat, and eventually fails), you build a shoreline out of oyster reefs, mangroves, seagrass, and salt marsh. Living shorelines reduce erosion, filter incoming runoff, provide nursery habitat for juvenile fish, and lock up carbon in ways that hard armoring cannot.

The Brevard Zoo’s Restore Our Shores program has built oyster reefs, planted salt marsh, and installed living shorelines at dozens of sites along the Indian River and Banana River. NOAA and the Indian River Lagoon Council have funded larger-scale living-shoreline restoration in Mosquito Lagoon. This is the hands-in-the-water end of the work, and it is often where volunteers can participate.

Why they only work together.

None of these four is sufficient on its own. Muck dredging without stopping new inputs just fills the hole back up with more muck. Septic-to-sewer without dredging the legacy muck means clean inputs but continued leaching from the bottom. Living shorelines without treating the water they sit in cannot recolonize. Stormwater retrofits alone do not address the septic and muck problems.

The Save Our Indian River Lagoon program was structured to run all four in parallel across the ten-year plan — and to be adjusted every year by the Citizen Oversight Committee based on measured pounds of nitrogen prevented per dollar spent. That parallel structure is why the recovery has started to show up in the data. See the MRC 2025 Report Card for one independent read on how it is going.