2015 was the warmest year in history and 2016 is on its way to setting a new record. In the era of manmade threats to the environment, it may seem hard to believe that any human intervention can actually benefit the planet. But tens of thousands of manmade reservoirs already in use around the world demonstrate the present benefits and future potential of artificial water structures.
A Little History
Man has manipulated water to his benefit for millennia. The ancient Mayans created several gigantic artificial lakes that supported thousands of city dwellers. Like Maya, Sri Lanka also built tens of thousands of water tanks between the third century BC and the twelfth century AD to sustain irrigation. Today, there are more than 75,000 dams in the United States alone that generate clean hydroelectric power.
Present Water Manipulation Is More Important Than Ever
Modern urbanization poses a challenge to the natural fresh water supply. By 2050, two-thirds of the world’s population is expected to live in cities. Development is essential to accommodate this population boom, but development comes with environmental consequences. Construction releases pollutants that can end up in nearby waters. New structures also result in the loss of porous surfaces that soak up rainwater, leading to adverse effects on stream banks and aquatic life.
Fortunately, a variety of manmade water structures can complement development by absorbing the runoff from construction or offering new sources of fresh water.
Wet ponds are runoff holding facilities. They are built with vegetation, which helps hold sediment and nutrients contained in urban runoff. Once the vegetation finishes cleansing the runoff, the water in the wet pond is released to a nearby natural body to help preserve downstream habitats.
Wetlands contain much more vegetation than wet ponds and thus serve as excellent filters for urban runoff. Constructed wetlands provide reliable pollutant cleansing and may serve as an excellent habitat for wildlife.
In the not too distant future, manmade lakes may protect the environment by cooling power plants. Power plants generate electricity by using steam from burning fossil fuels to spin gigantic turbines. To make this process work, over 30% of American plants use fresh water from natural streams to cool their condensers. Because these plants release the used water back into the wild, local ecosystems and aquatic life are damaged. Manmade lakes offer an alternative that can conserve natural freshwater and preserve local environments. Crystal Lagoons, the company behind this project, also hopes to use the heat transferred to the water from power condensers to power desalination plants, which will add to Earth’s supply of freshwater.
Critics suggest that manmade lakes are a gimmick. Others worry about potential negative environmental impacts.
Of course, any manmade water project should be studied and evaluated critically before it’s built. Incorrect planning can indeed harm more animal and plant life than it will save. However, as is already evident by the historic use of manmade water structures, we have every scientific tool and plenty of incentives to develop land and property in a sustainable fashion.