Blue Cypress Lake — Sebastian, Florida

Blue Cypress Lake is a 6,555-acre cypress-ringed lake in western Indian River County, the largest lake in the county and the source of the St. Johns River.

FWC gives the acreage and describes a shoreline of cypress and spatterdock (FWC). Indian River County calls it a ten-square-mile lake and the origin of the St. John's River (Indian River County). The St. Johns Riverkeeper places the start of the 310-mile river on Blue Cypress Lake about 30 miles west of Vero Beach, and notes that the upper river has indistinct banks and no main channel (St. Johns Riverkeeper).

For Sebastian, the lake is the far western edge of home county. Sebastian sits on the Indian River Lagoon, a separate estuary, while Blue Cypress Lake feeds the St. Johns River system. The two water systems meet in county politics more than in geography: the same Indian River County Commission that sets rules on the lagoon side voted the biosolids moratorium that protects the lake.

Blue Cypress Lake is the first open lake of the St. Johns River, and the St. Johns River Water Management District manages the marshes around it as the Blue Cypress Conservation Area.

The District lists Blue Cypress Lake and Kenansville Lake on the western side of the conservation area, which belongs to the Upper St. Johns River Basin Project carried out with the U.S. Army Corps of Engineers. The project is now in long-term maintenance and is meant to reduce flooding, restore natural water cycles and protect water quality. One stated purpose ties it directly to Sebastian's side of the county: it reduces freshwater diversions to the Indian River Lagoon estuary. The District describes the area as one of the most undisturbed in the headwaters, with the largest remnant marsh of its type in the region and an intact sawgrass marsh on the eastern side of Blue Cypress Lake (St. Johns River Water Management District).

Indian River County added land in 2011. With a $1 million grant under the North American Wetlands Conservation Act, the county bought 350 acres of cypress wetland and upland with about 4,700 feet of shoreline on the northwest edge of the lake from Pressley Ranch. The Conservation Fund negotiated the sale, and the county's only expense was $30,000 for that work. A county environmental planner told commissioners that nearly all the land west of the lake counts as headwaters of the river, and that the tract would be reached mainly by boat (Vero News, 2011).

Blue Cypress Lake is best known for ospreys, with Indian River County reporting over 200 osprey nests along the shoreline, plus bald eagles, alligators and wading birds.

The ospreys nest in the cypress standing in open water. Vero News described the trees as 130 feet tall in 2025 and listed ospreys, alligators and bald eagles among the lake's wildlife (Vero News, 2025). The county's park page calls the lake a top osprey nesting site and names bass, catfish and alligators along with the birds (Indian River County).

The marsh on the District land supports a longer bird list. The St. Johns River Water Management District identifies foraging and nesting habitat for the snail kite in the eastern portion, along with great blue herons, white ibis, snowy egrets, limpkins, night herons, wood storks, ospreys and bald eagles (St. Johns River Water Management District). Wood storks and ospreys on that list are also familiar birds over the Indian River Lagoon at Sebastian, while the snail kite habitat is specific to the marsh.

FWC describes Blue Cypress Lake as having a good population of largemouth bass, bluegill, redear sunfish, black crappie and catfish, with buoy-marked fish attractors in open water.

FWC's TrophyCatch tracker, which rewards anglers for documenting and releasing bass of 8 pounds or more, lists 12 Lunker Club bass of 8 to 9.9 pounds submitted from Lake Blue Cypress. The forecast notes that bass move shallow to spawn as the water cools in October and November, and it directs anglers to Middleton's Fish Camp for daily conditions (FWC). Indian River County calls the lake a premier location in Florida for largemouth bass (Indian River County). For Sebastian anglers, it is the largest freshwater fishery in Indian River County.

The public way onto Blue Cypress Lake is Middleton's Fish Camp Park, a 23-acre Indian River County park at 7400 Blue Cypress Lake Rd. with two boat ramps and a floating dock.

The county lists boating, kayaking and canoeing, fishing, birding, hiking and restrooms with showers at Middleton's. Swimming is prohibited there, as are smoking, fireworks and dumping, under the posted park rules (Indian River County). The surrounding Water Management District land has its own access points and a network of primitive campsites, and the District permits wildlife viewing, seasonal hunting, bicycling and hiking along many miles of levees. Airboat tours run from the 512 Recreation Area by appointment with independent vendors, and the L-77 West Levee area, also called Lake Garcia, is an idle speed zone (St. Johns River Water Management District).

The 512 in the Blue Cypress Recreation Area's name is the route number of County Road 512, the same road that runs through Sebastian and Fellsmere.

A 2018 blue-green algae bloom on Blue Cypress Lake led Indian River County to ban Class B biosolids, treated sewage spread as fertilizer, and the county has renewed that moratorium since.

The sequence is documented in Vero News. On July 12, 2018 the Florida Department of Environmental Protection ordered a 180-day stop to biosolids dumping at Pressley Ranch near the lake while it studied nutrient sources with the Water Management District (Vero News, July 2018). That month the county commission banned hauling and spreading of Class B biosolids on unincorporated land for six months, and Fellsmere moved to adopt the same rule, which would make the whole county biosolid-free because no other city in the county had farms using the material (Vero News, August 2018).

The county's study, by Jones Edmunds and Associates, reported in December 2018 that biosolids were the pollution source and that phosphorus in the lake had climbed sharply. Vero News traced the shift to a 2012 state ban on biosolids in the Lake Okeechobee, St. Lucie and Caloosahatchee watersheds, after which more of the material flowed north into Indian River County (Vero News, December 2018). The commission extended the moratorium to January 2021 (Vero News, 2020) and voted unanimously in December 2022 to extend it again; CBS12 reported that state law bars permanent bans but allows existing moratoriums to be extended (CBS12).

Monitoring of Blue Cypress Lake continues. Vero News reported that the Florida Department of Environmental Protection collected a water sample on May 15, 2025 at the 10-square mile lake and found a blue-green algae bloom, and that local officials advised visitors to stay out of water where a bloom is visible (Vero News, 2025).