Environmental Impacts
Extreme Weather
Stormwater and Runoff
With increased ocean and air heating, extreme weather is becoming more common with more intense storms, flooding, stormwater runoff, and extreme droughts (USGCRP, 2018). From 1980-2024, there were 403 confirmed weather/climate disaster events with losses exceeding $1 billion each in the United States. The 1980–2024 annual average is 9 events (CPI-adjusted); the annual average for the most recent 5 years (2020–2024) is 23 events (CPI-adjusted). (NOAA, 2025). The summaries below are, in part, from recent reviews including Herring et al., (2018), USGCRP (2018), Parkinson and Siedel (2018), IPCC (2019), and (NOAA, 2025).
More rainfall increases the runoff of fertilizer and sediments into the lagoon from many canals, tributaries, road sources and land sources contributing to build-up of more muck on the bottom of the lagoon (IRL CCMP, 2019). Old wastewater infrastructure is increasingly overloaded with rapid continuing development, leaks at scales ranging from fields of septic tanks through large public sewer facilities occur, especially with more stormwater and flooding events, and background rises in sea level (e.g., Barile, 2018; Young, 2020). These and other factors combine to increase the chances of harmful algal blooms and ecosystem-scale impacts that include fish kills and threats to human health (Economic Impacts page). At the scale of local and regional utilities, many other challenges will occur without adaptation planning and action to develop climate-ready public water infrastructure (e.g., Bloetscher et al. 2011).
Source: City of Port Orange, Volusia County, FL
Source: National Hurricane Center
Hurricanes and Tropical Storms
Increasing ocean heat content fuels rapidly intensifying hurricanes and tropical storms (>74 and 39-73 mph, respectively) which can damage large swaths of seagrasses, mangroves, and reefs in our region, (e.g., Steward et al., 2006; National Ocean Service, NOAA, 2025). Millions of humans and the social and economic systems that support them are also highly vulnerable in coastal areas (e.g., Carter et al. 2018; USGCRP, 2018), as many long-time Florida residents know. For example, the relatively small Hurricanes Jeanne and Francis heavily damaged over two dozen cities and towns up and down the Indian River Lagoon after landfalls in 2004, with impacts that lasted for years after (e.g., Treasure Coast Palm, 2019).
Record high sea surface temperatures, with reduced wind shear and other factors, are associated with higher than usual numbers of major hurricanes in the Northwest Atlantic in the 21st century, such as 2017 (Lim et al., 2018; Klotzbach et al., 2018). There were more named storm days, major hurricane days, and accumulated cyclone energy in September 2017 than any other month on record (Klotzbach et al., 2018). Since 2018, many large storms have made landfall in Florida with catastrophic impacts extending inland to the Carolinas and beyond (Tampa Bay Times, 2025). Almost all of these storms were born and raised among the extremely high, record-setting sea surface temperatures of the Gulf of Mexico (e.g., National Ocean Service, NOAA, 2025). Hurricanes and tropical storms coupled with dense coastal development have resulted in trillions of dollars in U.S. damage costs over the past several decades and trends in losses continue to increase (Gori et al., 2025).
Extremes in Storms and Drought
Reduced rainfall during drought conditions can also be punctuated by heavy rain events. Results in coastal areas can include pronounced estuarine salinity swings, higher pulses of runoff, and amplified erosion (USGCRP 2018; Parkinson and Siedel 2018). More of these events along the lagoon can impact water quality with both short- and long-term impacts that can further degrade availability and quality of habitat for coastal plant and animal species. For example, several species of IRL fishes are threatened by overdevelopment and changes in freshwater inflows. These impacts can be amplified by climate change drivers such as hotter temperatures and more extreme weather. These changes add to existing pressures on IRL fishes already threatened by overdevelopment, herbicides, and water flow changes, including the River Goby, Bigmouth Sleeper, and Opossum Pipefish (Gilmore et al., 1992).
If interested in volunteering or otherwise taking action on issues above, the What We Can Do page can assist.