Wherever people live in any quantity around water, in both urban and rural settings, something happens that causes the water to stink.
It’s called hypereutrophication. Hyper – meaning “too much” plus eutrophication meaning nourishment, that is, “too much food”, mostly in the form of nitrates and phosphates, sewage, fertilizers, etc.
Farming is the major culprit, but we all contribute and trying to make someone else wrong just isn’t wisdom. But consider that now we know how to take the nutrients that are at the heart of today’s problem and turn them into tomorrow’s fish.
Here’s a look at a flow chart that helps understand the issue:
Even if all incoming nutrients are prevented somehow via storm water management or other aggressive, expensive stewardship practices, there will still be a certain volume of nutrients, built up over time, in the lake’s sediment. During those moments between algae blooms, when water clarity finally improves and sunlight reaches down to those nutrients, or when a weather or wind event kicks them up, the whole process starts over. You’ve likely seen it. Or smelled it.
The answer comes from nature. She’s been inventing for a very long time. The natural prototypes that didn’t work were discarded…we call it evolution. The model that does work is called “The Wetland Effect.” Here’s a list of the primary variables associated with wetlands:
- Surface area.
Are you surprised by the shortness of the list? Certainly there are other factors that add to the wetland effect, or that limit it. These include: residence time, solar energy, available carbon, nutrients, temperature, plants, pH, salt, habitat design, micro nutrients, heavy metals, exposure to toxin, and a few others. But the primary variables are simple, and workable. With surface area and circulation/aeration leading the way, the other variables become manageable. Without the primary conditions, it doesn’t happen!
Unless you are very lucky, or you live far away from people, or perhaps your system is somehow immune to global warming, in any case, without surface area and circulation/aeration, your waterway will not grow enough of the absolutely critical microbes that clean up after us. The wetland effect is nature’s septic system, nature’s biofilm reactor. Without it, nasty things stack up quickly!
What does this boil down to? What does it mean? The short answer is…We Have The Science. We know how to design for microbial nutrient uptake. Our ability to steward for a quality environment is here now. Stinky lakes devoid of healthy fish…we can do far better.