Miami Environment Guide: Biscayne Bay, Sea Level and the Everglades

The Miami environment section has four deeper guides, on Biscayne Bay, sea level rise, the mangrove coastline and the Everglades edge, and this hub answers the questions that send residents to each one.

Two governments share the work. The City of Miami posts King Tide dates (City of Miami King Tides), lists neighborhood flood projects under Resilience and Public Works (City of Miami) and runs the Miami Forever Bond (Miami Forever Bond). Miami-Dade County's Department of Environmental Resources Management (DERM) compiles the annual Biscayne Bay Report Card (Miami-Dade County) and takes environmental complaints, including fertilizer ordinance violations (Miami-Dade DERM).

Last verified: October 15, 2026, on the City of Miami, Miami-Dade County, Florida DEP, National Park Service and NOAA websites.

Biscayne Bay is still under strain in 2026: the Miami-Dade County report card release says every region of the bay remains in either poor or fair condition overall (Miami-Dade County).

Many areas, particularly in northern Biscayne Bay, continue to show high levels of nutrient and bacteria pollution that exceed established criteria, according to the same release.

Mayor Daniella Levine Cava said the report card is now in its eighth year. The 2026 edition reflects work by field biologists and the scientific team in DERM, who collect and analyze thousands of samples from 138 water quality stations and 475 benthic habitat monitoring sites, looking at nutrients, bacteria and chlorophyll-a, water clarity and the health of seagrass and sponges, scored green, yellow and red for good, fair and poor (2026 report card release). A few areas moved from poor to fair. Water clarity improved or remained stable in multiple areas, northern Biscayne Bay areas previously affected by significant seagrass loss showed encouraging signs of ecological recovery, and seagrass reached its highest coverage since 2018 in some areas.

The county names everyday sources rather than one polluter: stormwater and sediment runoff into storm drains, uncollected dog waste, lawn fertilizer during the rainy season, trash discarded on streets or into canals, leaky or poorly maintained septic tanks, and improper disposal of fats, oils and greases from homes and businesses (Miami-Dade County).

Much of the bay is state protected water. Biscayne Bay Aquatic Preserve extends the length of Biscayne Bay from the headwaters of the Oleta River south to Card Sound near Key Largo, excludes all waters of Biscayne National Park, covers 64,607 acres in Miami-Dade and Monroe counties and was established in 1974 (Florida DEP). The Florida Department of Environmental Protection describes Biscayne Bay as a subtropical estuary with mangrove-lined shores, hardbottom communities and seagrass beds, says the preserve is considered Outstanding Florida Waters, and notes that the bottlenose dolphin and the West Indian manatee live in the bay (Florida DEP). Biscayne National Park, within sight of Miami, is 95% water and protects coral reefs, mangrove forests, Biscayne Bay and the northernmost Florida Keys, with guided eco-adventures departing from the Dante Fascell Visitor Center (National Park Service). The Miami Biscayne Bay guide covers the bay in more detail.

NOAA's tide station at Virginia Key shows relative sea level rising 1.26 inches per decade, plus or minus 0.04 inches, over a record that runs from June 1931 to December 2025 (NOAA tide station 8723214).

That trend comes from station 8723214 on Virginia Key, which NOAA combines with the older Miami gauges 8723170 (1931 to 1981) and 8723080 (1981 to 1992) to build the full record (NOAA CO-OPS).

King Tides are the flooding residents see. The City of Miami says a King Tide is a higher-than-normal tide that typically lasts about 3 hours and occurs annually and predictably, in September through November in Miami, and can cause sunny day flooding on streets or other areas near waterways and the coast, as well as in low elevation areas of the city that are not coastal (City of Miami King Tides). The city says King Tides can be observed 1.5 to 2 hours before and after peak times, and lists peak tide times for each 2026 date.

One stale page to know about: the city Shorecrest King Tide parking pass, a pilot that lets Shorecrest residents park free on 79th Street outside the flood zone, still listed only 2019 dates (including October 25 to 31) when checked on October 15, 2026 (City of Miami Shorecrest pass). Shorecrest residents planning around the October 24 to 30, 2026 peak should confirm the pass with the city before relying on it. The Miami sea level rise guide covers the topic in more depth.

The City of Miami's Miami Forever Bond allocates $192 million of its $400 million to sea level rise mitigation and flood prevention (Miami Forever Bond), and the city's Resilience and Public Works department lists neighborhood flood projects now in the works (Resilience and Public Works).

The bond invests a total of $400 million in five categories: sea level rise and flood prevention, roadways, parks and cultural facilities, public safety and affordable housing, and a Bond Oversight Board oversees project management and progress reporting (City of Miami). The city says the first tranche of flood prevention projects will focus on low-cost, high result investments such as tidal backflow prevention valves and additional capacity at current pump stations, and that future funded projects will be informed by the Stormwater Master Plan, which the city is updating to protect Miami from increasing flood risks for the next 40 to 50 years (City of Miami).

Current sea level rise and flood prevention projects listed by Resilience and Public Works include neighborhood flood improvements in 8th Street, Allapattah, Auburndale, Clemente, East Flagami, East Little Havana, Edgewater, Melrose, Shorecrest South and South West Wynwood, plus Brickell Bay Drive seawall and resiliency improvements (Resilience and Public Works). The department answers at (305) 416-1200 from the 8th floor of the Miami Riverside Center, 444 S.W. 2nd Avenue.

The Office of Resilience and Sustainability is on the 2nd floor of the same Miami Riverside Center, email [email protected]. Its stated priorities include advancing resilience to sea level rise, extreme heat and hurricanes, and reducing pollution and protecting Biscayne Bay, the Miami River and the Little River; its programs include the Stormwater Master Plan, Miami Forever Climate Ready and Resilient 305 (Office of Resilience and Sustainability).

Miami-Dade DERM takes reports of mangrove cutting, spills into Biscayne Bay and fertilizer ordinance violations at a complaint desk reached at 305-372-6955, 24 hours a day, 7 days a week (Miami-Dade DERM).

The DERM list covers liquid discharges or spills into storm drains, waterways or onto open ground, turbid (cloudy) discharges in any waterway, canal or Biscayne Bay, dredging or filling in the bay, lakes or wetlands, removal, cutting or hat-racking of trees, and removal, cutting or trimming of mangroves in coastal areas (DERM complaints). DERM asks for an address or the most accurate location information possible. Flood or drainage complaints go elsewhere: the county Stormwater Utility information line at 305-372-6688. The Miami mangrove coastline guide covers mangroves in more depth.

The countywide fertilizer ordinance is the other rule to know. No fertilizer containing nitrogen or phosphorus may be applied in Miami-Dade County from May 15 through October 31, and fertilizer is never allowed in fertilizer-free zones within 20 feet of the top of the bank of any water body, stormwater drain, Biscayne Bay, wetlands or the top of a seawall (Miami-Dade fertilizer rules). The yearly cap is no more than four pounds of nitrogen per 1,000 square feet. The ban runs until October 31, so in mid October 2026 it is still in force.

Everglades National Park, established in 1947 as the first national park created for its biodiversity, protects 1.5 million acres of wetland, forest and marine habitats and provides a major source of drinking water for local residents of South Florida (National Park Service).

The water under Miami-Dade is part of the same story. FDEP says groundwater discharge from the Biscayne Aquifer, which is composed of porous limestone, flows into Biscayne Bay and contributes to its salinity regime, and that during the dry season canals recharge the aquifer, while in the wet season they drain it (Florida DEP). The Miami Everglades edge guide covers the connection between the city and the park in more depth.