On the opposite end of the water storage spectrum, groundwater is often pumped during periods of high volume and stored for future use. Many aquifers and water tables recharge seasonally due to snow melt, creating excess groundwater that can rise high enough to flood low lying areas and depressions. Pumping out the excess groundwater produces an accessible surface water supply while controlling rising water tables. Yet, this water needs even more careful handling and specialized storage equipment to keep it potable for human consumption or clean enough for irrigation and livestock use. This section will explore how to build groundwater storage ponds that work well for all kinds of freshwater uses.
The Value of Extracting and Storing Groundwater
Each groundwater extraction project likely has more than one major purpose, depending on the region and local surface water supplies. Some arid areas simply don’t collect enough rainfall in rivers, lakes, and other surface water sources to supply all of the drinking and irrigation water required per year. But this is far from the only reason for pumping and storing groundwater at the surface. The exact purpose, or purposes, of a groundwater storage pond is what guides its design. So, make sure you narrow down the options before beginning a new project.
Drinking and Irrigation
In dry climates, located in coastal areas where surface water tends to have a high salinity, groundwater is often the only reliable supply of drinking and irrigation water. Homeowners routinely rely on small wells to tap into shallow groundwater supplies, but municipal pumping stations can reach deep aquifers that supply a much larger amount of fresh and potable water. Areas as varied as Florida and South Carolina’s coastlines, India’s agricultural belts, and Morocco’s desert communities and farms, rely on groundwater pumping and storage for their primary water supply. The ponds used for storing millions of gallons of potable water and irrigation supplies must be built with liners designed for that use. Look for liners rated by the National Sanitation Foundation (NSF) with a designation of at least NSF-61 or greater. These liners will work for all potable, agricultural, and livestock uses without concerns about chemicals leaching into the water supply.
Storing groundwater above ground makes it accessible during both extreme droughts and regular seasonal dry periods. In some areas, underground aquifers dry up during these seasons and only refill during wetter periods. Moving the water above ground, and covering it to prevent evaporation, can prevent it from draining away naturally to deposits too deep to tap with conventional wells and pumps.
Power generation plants, that require a constant source of freshwater for cooling, usually rely on nearby storage ponds. The wastewater is similarly discharged to a lined storage pond after it’s used, especially if there’s a chance for reuse on the premises. Freshwater is often required for these cooling purposes, since contaminated groundwater doesn’t always offer the right amount of heat transfer characteristics. Mixtures with various chemical or mineral compounds can also leave behind deposits on sensitive power generation equipment. Cooling water is usually needed in such high volumes that the ponds are constantly refilled with fresh groundwater by a large-scale pump to keep up with demand.
Control of Flooding
Pumping up groundwater and storing it at the surface can prevent flooding in low lying areas where the water table rises above the soil’s surface. Temporary ponds are often used for dewatering construction sites, but the same areas often require long-term groundwater pumping to keep the structures dry during heavy rainfall events. The water pumped for flood control can be repurposed for irrigation or drinking water if it’s kept clean or treated during storage. Some areas that once absorbed water rapidly enough to prevent flooding now need pumping due to the addition of thousands of square feet of impervious surfaces and depletion of the water table’s ability to hold moisture.
Industrial and Mining Uses
The majority of new mining and industrial manufacturing sites are located far from rivers, lakes, and other surface water sources. Yet, these processes can require hundreds of thousands or millions of gallons of water per year. In fact, each individual, horizontal well used for hydraulic fracturing can require more than 40 million gallons of fresh water to push the oil and gas out of the ground. It’s hard to find a nearby source for that much water without tapping into the groundwater supply below your feet. Setting up storage ponds helps stabilize water supplies for mining and industrial facilities, to keep them running smoothly regardless of weather and location.
Some of the world’s most popular tourist attractions rely on groundwater pumping to supply enough water for outdoor sports of various types. Resorts and hotels in desert areas through the Middle East generally rely on groundwater to keep their plumbing systems and pools supplied all summer long. In colder climates, ski resorts often turn to stable groundwater supplies when it’s necessary, to freeze man-made snow and make up for a lack of natural snowfall. It takes a lot of water, with a steady daily flow, to keep a snow resort covered when there’s nothing falling from the sky. So, storage ponds are a great option for smoothing out the pumping demand over time at these tourist attractions. Recreational and fishing pond attractions also often rely on groundwater supplies to keep them topped off throughout the year.
Livestock Rearing and Meat Processing
Livestock like cattle, pigs, poultry, and even sheep require a surprising amount of water per year. This includes the water directly consumed by the animals, in addition to irrigation needed for their pastures, and the water used for washing barns and processing equipment. For common types of livestock, average water use figures include:
This is just the drinking water required per animal and doesn’t account for thousands of gallons of cleaning and irrigation water per year. Meat processing plants also require a steady supply of clean groundwater to sanitize meat products, wash off equipment and floors, and provide moisture for ice coating to rapidly freeze products and preserve their quality.
No matter your reason for pumping up and storing fresh groundwater, a storage pond is a convenient way to do it. Don’t forget your potable water safe liner from BTL Liners to keep your pond clean and safe for all uses.