If you look up facts or images for the water cycle, you’ll see plenty of cute, colorful graphics showing rivers, clouds, and oceans. Many children learn about the stages of the water cycle at school, and it's knowledge they might carry through their lives. However, the water cycle is changing — and it’s all due to human activity.
Where once all rivers flowed freely, now many are dammed or redirected. Agricultural demands impact water supplies, and climate change may be shifting the supply and demand of water in some parts of the world. Plus, the rise of microplastics and other contaminants could be affecting just how much clean water is available without proper filtration.
Understanding how we're impacting the water cycle could help you make choices that ensure your family invests in clean, pure water for your home.
The 7 Steps of the Water Cycle
The water cycle or hydrological cycle describes how water endlessly moves around our planet. It shifts from solid to liquid to vapor and back again thanks to this cycle. Around 71% of the Earth’s surface is covered in water, and nearly 97% of this is held in the oceans. Of course, we can’t drink salty ocean water. The stages of the water cycle describe how that water ends up in our homes, schools, and businesses.
1. Evaporation
All water on Earth has existed in another form before. Water has three states: liquid, solid, and gas. The solid form is ice, and the gaseous form is water vapor. When water in oceans, rivers, and lakes heats up under the light of the sun, it evaporates and rises as vapor.
2. Transpiration
Water vapor doesn’t just come from bodies of water, though. Quite a lot of it comes from plants. Plants absorb water to aid in photosynthesis and growth. However, most of the water they take in ends up returning to the atmosphere via a process called transpiration. Holes in a plant's leaves called stomata open and close to allow carbon dioxide in. During this process, water evaporates and rejoins the water cycle.
3. Sublimation
You may be surprised to learn that water can transform directly from its solid state into vapor. A combination of changing air pressure and wind can cause ice and snow to shift directly into water vapor. This is called sublimation and tends to happen at high altitudes such as in snowy mountains.
4. Condensation
All that water vapor doesn’t just stay in the atmosphere. Eventually, it cools and condenses, forming clouds. Occasionally, water vapor will condense at lower altitudes, resulting in fog.
5. Precipitation
Probably the most well-known aspect of the water cycle is precipitation. Clouds collide and are impacted by air pressure and temperature, causing water droplets to fall back to Earth in the form of rain. Water vapor can also freeze and become snow.
6. Surface Runoff
Some of this precipitation runs down mountains and over the ground to become part of streams, rivers, lakes, and oceans. This runoff water starts the water cycle again.
7. Subsurface Flow
Some water seeps through the ground and is stored in aquifers as groundwater. Eventually, it may resurface as springs or make its way to oceans.
How Humans Have Interrupted the Stages of the Water Cycle
Each of these stages can be interrupted. When humans deforest a large area, this can massively impact how much water vapor is produced. Without rainforests, for example, there isn't as much rain.
When water is dammed, for example, to create reservoirs, this also interrupts the water cycle by removing large volumes of water from where it originally flowed. Hydroelectricity is another cause of this, shifting water away from ecosystems that may suffer without it.
Agriculture is a major contributor to a changing water cycle, accounting for 70% of worldwide water use. Irrigation moves immense volumes of water from one place to another. However, this also creates problems by leaching minerals and nutrients out of the soil and into groundwater.
The Environmental Impacts of Our Actions
When water suddenly isn’t available in a place it used to be, the environmental impact can be catastrophic. Deforestation doesn’t just remove habitats for animals — it leads to drought. In 2023, the Amazon Rainforest experienced its worst drought in recorded history and scientists lay the blame directly at the door of deforestation.
Damming and redirecting water can be an intelligent way to ensure communities have both water and power. However, it’s a process that’s easy to mismanage. Without water, ecosystems can die. So if a section of a river that once ran deep becomes a shallow stream, that can impact thousands of species. Humans will also suffer, particularly if some of the wildlife affected are pollinators that help us grow crops.
The problem with constantly irrigating soil and leaching it of its nutrients has a double impact. Firstly, those nutrients flow into groundwater and change the quality of the stored water. Mineral-rich water may need additional cleaning and filtering before it is safe for humans to drink. But beyond that, poor-quality soil requires more fertilizer. The constant use of chemical fertilizers also causes damage to the environment and impacts local water supplies.
The Added Problem of Microplastics
Plastic takes hundreds of years to biodegrade. With 8 million tons of the substance dumped in oceans every year, this is a problem. As the plastic collides with other ocean items, it gets broken up into tiny particles called microplastics. Unfortunately, those microplastics are now entering our drinking water. In fact, over 94% of U.S. tap water samples contain microplastics, and bottled water is also noted to be contaminated.
While no major health risks have been identified so far, it’s clear why many householders are looking at the benefits of water filtration systems to ensure clean, pure water for themselves and their families. Filtering water provides two advantages: you improve the quality of your tap water and you reduce your reliance on bottled water, which cuts down on how much plastic is used every year. The more each of us does for the environment, the less the water cycle will continue to be impacted by our actions.
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