Water is important for everyone, but its sources are different, like some of it found on the surface and some is underground. These two types of water play a very important part in our daily lives, and also impact the water we drink and the environment we live in. But which one is safer to drink? Which one is running out faster? And why should we care?
In this article, we will guide you about what’s the difference between Surface Water Vs Groundwater and explain why it matters in our lives.
What is Surface Water?
Surface water is the water that we see every day on the earth’s surface, like on rivers, lakes, oceans, and reservoirs. This water usually comes from natural springs or rainfall and is mostly used in our daily lives, such as for drinking, irrigation, and for industrial purposes.
Since surface water relies on rainfall and climate, droughts can lead to shortages. Surface water can contain contaminants in high amounts due to direct exposure to pollutants, because chemicals and contaminants can easily go into the rivers and lakes.
Surface water
According to the U.S. Geological Survey (USGS), only 1.2% is surface water from all the freshwater on earth, making it a limited but vital resource, while groundwater accounts for 30%. Even though it is very easily accessible, and just need to go through some treatment before drinking safely.
What is Groundwater?
Groundwater is the water that we find below the Earth’s surface, like aquifers that are made up of layers of rock and soil, that holds water. As the water from rivers and lakes moves through these layers, many impurities are removed, and groundwater becomes cleaner than surface water.
Groundwater
Groundwater is 30% of all the freshwater on Earth, and is the best source for drinking, farming, and industry. Since it is underground, groundwater is less exposed to pollution than surface water. However, chemicals from farming, factories, and household waste can still contaminate it.
However, while groundwater is a critical water source, excessive extraction and slow replenishment have raised concerns about long-term availability. To combat this, experts are focusing on groundwater recharge methods to help sustain this vital resource.
Surface Water vs Groundwater: The Key Differences
| Features | Surface Water | Groundwater |
| Location | Rivers, lakes, oceans | Underground aquifers |
| Accessibility | Easy to access but needs treatment | Requires wells but often cleaner |
| Susceptibility to Pollution | High (exposed to contaminants) | Lower (filtered naturally underground) |
| Availability | Affected by droughts and climate change | More stable, but slow to replenish |
| Uses | Used for hydropower, irrigation, and drinking water. | Used for drinking, farming, and industry. |
Why is Groundwater Important?
You might not think about water surfacing from underground, but groundwater is very important. It is like a backup supply when the surface water levels go down and helps keep rivers and lakes from drying up by slowly adding water during dry seasons.
Almost 2.5 million of the world’s population depends on the groundwater for drinking. It acts as a natural water storage system and provides water during droughts, and also supports rivers and wetlands to maintain the ecosystems healthy.
Sadly, groundwater is being used up too quickly, mostly for farming and city water supplies. If an aquifer runs out of water, then it can take decades, or even centuries, to refill. To prevent over-extraction, regular groundwater monitoring is essential for tracking water levels and ensuring sustainable use. This is why groundwater is often called “the hidden resource”, we don’t see it, but we depend on it every day.
Minerals in Water- Why all this Matters?
Both surface water and groundwater contain essential minerals that contribute to human health. Surface water often contains lower mineral content because it is more exposed to external pollutants and is frequently treated before consumption.
Groundwater, on the other hand, usually contains higher concentrations of calcium, magnesium, and potassium, and it makes it hard water. Water hardness is measured in milligrams per liter (mg/L) of calcium carbonate:
- Soft water: 0-60 mg/L (low minerals)
- Moderately hard water: 61-120 mg/L
- Hard water: 121-180 mg/L
- Very hard water: Above 180 mg/L (high minerals)
Water hardness is categorized based on its calcium and magnesium levels, influencing whether it falls under hard or soft water. Hard water can cause white buildup (limescale) in pipes, faucets, and appliances, and make them less efficient. Many people use water softeners to prevent this.
Even though groundwater is usually cleaner than surface water, testing for contaminants is still necessary to ensure it meets safety standards.
Which One is Better?
Both are essential for different uses. Surface water is easier to access but more prone to pollution, while groundwater is usually cleaner but can run out if overused.
For daily drinking water, groundwater is often preferred because it’s naturally filtered and less contaminated. And during droughts, groundwater is more reliable since it doesn’t evaporate as quickly. For industries and agriculture, surface water is widely used because it’s easily accessible.
However, with climate change and human activities affecting water sources, water scarcity solutions are crucial to maintaining a sustainable water supply for future generations.
Conclusion
In conclusion, both surface water and groundwater are important resources that we depend on for drinking, agriculture, and maintaining ecosystems. However, they face significant challenges from pollution, overuse, and the impacts of climate change. We should take steps to protect and conserve these water sources for the health of our planet and future generations.
FAQs
1- Can we drink surface water directly?
No, surface water needs to be treated before drinking because it’s exposed to pollutants.
2- How can we protect both surface and groundwater?
Reducing pollution, conserving water, and preventing over-extraction can help preserve both sources.
3- Why is groundwater cleaner than surface water?
Groundwater is naturally filtered as it moves through soil and rocks, removing many impurities.
4- Why is water blue in the ocean?
Ocean water appears blue because it absorbs colors in the red part of the light spectrum and reflects and scatters the blue wavelengths of light. This scattering effect makes the ocean look blue to our eyes. The depth of the water, the presence of algae, and the angle of sunlight can also affect its color, sometimes making it appear green, turquoise, or even brown in certain areas.
5- Can surface water drain to a foul sewer?
No, surface water should not drain into a foul sewer. Foul sewers are meant for wastewater from toilets, sinks, and kitchens. Surface water, like rainwater, should go into a surface water drain to prevent flooding and pollution.
