Surface water runoff that carries minerals, nutrients, and debris into ponds and lakes causes excessive plant and algae growth. Florida homeowners can slow the eutrophication process by using less fertilizer, stopping septic wastewater seepage, and installing plants at the edges of water bodies.
Eutrophication: it’s a process that starts when bodies of water receive excessive amounts of minerals and nutrients that cause out-of-control algae and plant growth.
Why should you care? Because it may be happening in your backyard pond, and you can do something about it.
We’re addressing eutrophication in this landscaping blog because the problem originates on land with the things that homeowners allow to sweep into canals, ponds, and lakes.
The Bad Things Homeowners Do to Good Water Bodies
Most homeowners don’t set out to ruin the ponds and lakes they live near. No, they usually love their waterways and want them to stay healthy and beautiful.
But here’s what often happens.
When it rains, the rainwater either soaks into the soil or runs across it, seeking low areas to settle into. As it traverses the ground, it picks up stuff along the way: fertilizer, loose dirt, leaves, grass clippings, and animal waste. When a canal or pond is close, the runoff water finds its way into those bodies.
All the debris in the runoff then dumps into the waterbody. Fertilizer ingredients phosphorus and nitrogen work in water as they do on land: they promote plant growth. Ponds and lakes subject to this runoff start to fill up with plants and algae.
As aquatic vegetation completes its life cycle, it dies and decomposes. Dead plants and algae end up as sediment on the bottom of the waterbody. The sediment layers build up, and the pond or lake becomes shallower and shallower.
Sunlight can now reach the bottom of the pond. Overall temps of the pond water increase, which encourages more plant and algae growth. Surface water runoff continues to dump minerals, nutrients, and debris into the pond or lake.
Eventually, the waterbody is filled with sediment and choked with aquatic plants. Gone is the freely moving deep water and, after a while, gone are the fish and organisms that once thrived in a healthy ecosystem.
What Can Homeowners Do?
Concerned homeowners can take measures to mitigate eutrophication in the ponds or lakes on their land.
1) Let a band of native plants grow around the edges of the waterbody. Environmental scientist and lake manager Paul Conti says that a wide strip of native plants between a mowed yard and a canal, pond, or lake will act as a barrier to the debris in water runoff. The plants will soak up the runoff water, absorbing minerals and nutrients and keeping them from entering the pond or lake.
(A side benefit of this strip of plants is its stabilizing effect on the banks of the pond. Where erosion is occurring, the roots of the plants will anchor soil and keep it from tumbling into the pond.)
2) Homeowners can limit the amount of fertilizer they use and properly dispose of debris such as leaves and grass clippings.
3) Homeowners with septic systems can have tanks inspected to ensure that wastewater is not leaching into the ground and going into nearby water bodies.
Eutrophication is a problem in Florida, and we can see its effects in many of our ponds, lakes, and waterways. Caring homeowners can help to slow eutrophication and restore the health of aquatic ecosystems on their properties.