Why would a river organization want to talk about groundwater? Beneath the surface, groundwater quietly supports much of the life above it, including the rivers we love and the drinking water we depend on. In my last post, “When it Rains, it Pours: Spring Storms Impact the Cahaba River” I briefly touched on the importance of rain and how it is connected to groundwater. Many may ask: “Is groundwater really that important?” Understandably, to many, groundwater is ‘out of sight, out of mind.’ In this post I will go more in depth into what groundwater is, its importance to rivers, and how we can protect it.

 

Groundwater Simplified

In simple terms, groundwater is any water that has soaked below the surface of the earth. When precipitation falls to earth, anything that sits on top of the ground, or moves across the top of the ground is “surface water.” This includes runoff, ponds, streams, and even lakes. But if the water soaks into the soil, it becomes groundwater. Once water soaks into the ground it still moves, sometimes very slowly. Some groundwater is located close to the surface, while some moves to be held in the soil, between and within layers of rock, and even within rocks. A body of rock or sediment that holds groundwater is considered an aquifer. As the water moves into the aquifers, it recharges them. From these aquifers, water can resurface to feed rivers, lakes and wetlands.

 

The Importance of Groundwater

Groundwater is used for a variety of things including irrigation for crops, a variety of industrial processes, drinking water, and is critical for the health of our ecosystems. The last two items are most relevant within our discussion: drinking water and ecosystem support.

Of the freshwater that is available for use on our planet, the vast majority of it is groundwater. Groundwater, via wells, is the primary source of drinking water for billions of people around the world. Even in Alabama, many people who live in rural areas rely on wells, which pull from groundwater, for their drinking water. In cities like Birmingham, groundwater can help to ensure a steady supply of water when river levels drop. The Cahaba River, for example, supplies drinking water to around 400,000 people in the Birmingham area, but when rainfall is scarce, groundwater can help fill the gap, making our drinking water system more resilient.

Groundwater also plays a critical role in river health. In dry seasons, groundwater seeps into streams and rivers, helping them flow even when there’s little rain. This slow release of cool, clean water is what keeps many creeks and rivers alive through the summer. Without it, sensitive aquatic species—like the ones that make the Cahaba one of the most biodiverse rivers in North America—would struggle to survive.

 

Protecting Groundwater

5 ways we can work to protect and enhance groundwater recharge:

• Sustainable Water Management: Efficiently using water to reduce the need for groundwater extraction. This includes the thoughtful use of water in your homes and yards, especially in times of drought. Sustainable water management is also critical for agricultural and industrial uses. 
• Land Conservation: Protecting natural areas that help support the ability of precipitation to soak into the earth near where it falls. This includes forests, wetlands, and especially areas along riverbanks (called riparian buffers). These natural ecosystems are the best and most efficient at allowing precipitation to soak into the ground and help filter water before it enters rivers and streams. These habitats are hard to mimic; but even yards and gardens are better than hard surfaces like roofs, concrete, and asphalt. 
• Green Infrastructure: Focuses on providing natural and green spaces for water to absorb into the soil in urban areas and around homes. These techniques include things like permeable pavements and rain gardens
• Regulation and Policies: The creation and enforcement of rules that prevent over extraction and pollution of groundwater. 
• Education: Helping individuals understand the importance of groundwater and the need to protect natural systems that ensure groundwater recharge.

When we protect groundwater, we’re protecting our rivers, our drinking water, and the ecosystems that depend on both. It’s invisible, but absolutely vital.

Tags: groundwater, rain