Contrary to popular belief, stormwater runoff—not industrial discharge—is the primary source of water pollution in Florida.  During a rain, anything on the ground can be picked up, carried via water, and taken downstream to the nearest body of water.  While newer construction projects require stormwater treatment (including detention ponds or newer techniques such as pervious pavement and biofiltration), the infrastructure in older coastal communities often pipes rainwater directly into local creeks, bayous, and bays.
A large storm drain empties into Pensacola Bay. Photo Credits: Carrie T. Stevenson, IFAS Extension

Pollutants contained in stormwater vary greatly in type and potential for damage. E. coli and fecal coliform bacteria from pet waste and septic tanks frequently cause closures of local swimming holes due to high bacteria counts.  Heavy metals from car exhaust, along with oil and grease from roads and parking lots can contaminate fish.  Litter from yards, roadsides, and coastal areas can trap, injure, or kill wildlife.  Nitrogen and phosphorus from excess fertilization and organic debris can result in water bodies with oxygen deprivation, algae blooms, and in worst case scenarios, fish kills.  Even sediment and clay from dirt roads, eroding property, and construction sites can end up downstream, filling in creek bottoms or seagrass beds.

When creeks are filled with sediment, the small invertebrates that make up the bottom of the food chain are smothered, while turbidity (cloudy water resulting from sediment particles) and sedimentation in grass beds reduces the amount of sunlight reaching the grasses and prevents growth.

Pervious pavement allows rainwater to filter into the soil instead of running over parking lots. Photo Credits: Christopher J. Martinez, UF Agriculture and Biological Engineering.

The most difficult aspect of preventing stormwater pollution, also referred to as “non-point source” pollution, is that it doesn’t come from a single source but is the result of numerous cumulative impacts.  However, there are many ways that individuals can reduce their unintentional contribution to this problem.  When it’s time to fertilize plants, read and follow the label, and if you have questions, contact an extension agent to make sure you understand the proper amount to apply.  If you live on a dirt road that crosses a creek, encourage your neighbors to agree to having it paved—many county projects are held up by a handful of homeowners who don’t see the benefits to having a rural road paved.  Be sure to clean up pet waste, and if you’re on a septic system and have the capability to convert to sewer treatment, take advantage of that option.

While it can seem that these minor changes can’t make a big difference, there is much evidence to the contrary.  The US Environmental Protection Agency recently recognized the success of a Florida community that took assertive stormwater pollution prevention measures.  As a result of their actions, a polluted water body, Roberts Bay (Sarasota) was removed from the state’s list of impaired waters.

Carrie Stevenson
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