Groundwater Myths: The Misunderstood Water

Groundwater Myths: The Misunderstood Water

Most people don't think about where their water comes from when they turn on the kitchen faucet or shower head. Water appears and they're able to use it. 

Most people are aware that the water piped into their home ultimately comes from a common source like a lake or a river. However, some people get their water from a well via an underground aquifer.

Groundwater, in the simplest of terms, is water that seeps into the ground. When rain falls to the ground, some may flow along the surface to streams, lakes or rivers. Some of that rainfall is used by the plants, some evaporates, and some sinks into the ground, becoming groundwater. 

According to the U.S. Geological Survey, groundwater is water in the ground that fully saturates pores or cracks in soils and rocks. Water underlies the Earth's surface almost everywhere – beneath oceans, hills, valleys, mountains, lakes, and deserts. It is not always easy to get to or clean enough for use without treatment, but it exists essentially everywhere if you dig deep enough. 

Groundwater may occur close to the surface, or it may lie many hundreds of feet below. And not all groundwater is the same age. Water at very shallow depths could be just a few hours old, whereas water at great depths may have been there for several thousand years.

Groundwater can seem mysterious because it's not easily seen. And when something is unknown, it can garner some myths attached to its name. 

Myth #1-Groundwater moves rapidly

Groundwater moves very slowly through the layers of sand, dirt, and rocks to an underground aquifer. Aquifers are made of permeable materials and have spaces where the water can flow through. Groundwater from aquifers is then either pumped to the surface through a well or is brought to the surface naturally through a spring that flows into rivers and lakes. 

Myth #2-Groundwater removed from the earth is never replaced

Groundwater is replaced, or recharged, by rain, melting snow and irrigation. Some groundwater even seeps into the ground from lakes, rivers, and streams. Because groundwater is replenished, it's important to protect it and keep it as clean as possible before it seeps into the earth, taking contaminants with it. 

Myth #3-Groundwater is not a significant source of water supply

According to the National Groundwater Association, 95% of Texans depend on public drinking water and 17% of that is from groundwater. Additionally, over 1.3 million Texans rely on groundwater from their wells, using 137 million gallons per day.  About 73% of agriculture irrigation comes from groundwater and 99% of drinking water for the rural population comes from the groundwater supply. 
Groundwater plays a significant role in the total amount of freshwater available. According to NASA's Earth Observatory, only 2.5% of the Earth's water is fresh. Out of that small amount, 68.9% is from glaciers, 30.8% is from groundwater. Lakes and rivers make up only 0.3% of all freshwaters on Earth. 

What now?

Now that we know the significance of groundwater, it's important to protect and conserve it, especially when surface water is declining due to drought conditions. 


While contaminants such as microorganisms and heavy metals occur naturally, there are many things we can do to keep additional pollutants out of groundwater. Many of these suggestions can also help protect our surface water, as pollution that washes in runoff from our driveways, streets, and other locations often ends up in our lakes and streams.

  • When using fertilizers on lawns, gardens, and crops, follow the manufacturer's instructions and avoid using too much. In addition to potentially damaging your turf or plants, excess fertilizers, pest and herbicides and other such substances can be washed in runoff into streams, lakes and environmentally sensitive aquifer recharge areas.
  • Be careful when storing lawn chemicals, motor oil and other potentially hazardous substances outdoors. Leaking containers or spills can pollute groundwater. Check with local authorities or waste disposal services about safe ways to get rid of such unwanted materials. Often local agencies will hold hazardous waste collection events. Click here to check for local hazardous household waste programs.
  • If you use a septic system, make sure it is properly installed and regularly maintained. Septic systems must also be placed a safe distance from water bodies, wells, and other areas where they could seep into water supply. For more information about septic systems, their proper installation, and regulations in Texas, click here.


As with surface water, water waste is due to poor personal habits. The good news is there is a lot we can do to greatly reduce the amount of water we waste.

  • Indoors, one of the best things you can do to avoid wasting water is to check regularly for and fix leaking faucets and toilets. Replace worn washers and valves on sinks and pipes. A leaking faucet can waste more than 3,820 gallons of water a year.
  • Run dish and clothes washers only when fully loaded. Consider buying higher-efficiency models.
  • When getting a drink, brushing teeth, or doing the dishes, don't leave the water running. Try scraping plates over a trashcan or compost receptacle. Fill the sink with soapy water and rinse as needed. Put a pitcher in the refrigerator for drinking water instead of running the sink to wait for it to cool. Wash fruits and vegetables in a pan of water. Then, reuse the water on houseplants.
  • Outdoors, don't over-water your lawn or garden. Water early in the morning when it is cool to reduce evaporation.
  • Use native grasses or other plants that require less water. Consider xeriscaping for landscaping, using heartier, drought-tolerant plants instead of commonly used varieties that demand lots of water. You can learn more about xeriscaping here.
  • Consider harvesting rainwater when the weather permits. Because rainwater is free of salts, minerals, and other contaminants, it is ideal for watering lawns and gardens, and with proper treatment, drinking. Professional harvesting and storage containers are available on the market, ranging in size from small buckets to tanks that can hold thousands of gallons.
  • For more information about conservation and related topics, please visit the Brazos River Authority's website by clicking here.

Go here to learn more facts about groundwater. To see all water wells in Texas, Water Data for Texas has an interactive map that also details the aquifer each well is sourcing its water from. 

Groundwater is a vital source of water and an extremely important natural resource. It's important to manage it, protect it, and conserve it.4