Throughout history, the relationship between agriculture and rivers has been complicated. As of today, almost 85% of water consumption in the United States is used for agricultural purposes, according to the USDA Economic Research Service. Farmers and ranchers depend on water from rivers, lakes, springs, and reservoirs to have a successful season. Unfortunately, they can also be a source of harm to these natural resources.
People have been farming near rivers since the birth of agriculture. The Fertile Crescent, located in the Middle East, is one of the first places people began to grow their food rather than hunt and gather. The Euphrates and Tigris rivers are part of the Fertile Crescent. These rivers would overflow and deposit mineral-rich sediment and silt in the surrounding soil during the rainy season. This process, which takes place in most rivers, causes the soil surrounding rivers to be rich in nutrients and extremely fertile for growing crops.
Along with rich soil, rivers are also an ideal site to grow crops and raise animals because of water accessibility. Irrigation makes it possible to grow crops in dry arid places where it would otherwise be impossible to grow food. It can be beneficial to grow food in these hot arid places. Their seasons tend to be longer, and often farmers can get two harvests in one season because they don’t have to deal with an autumn frost as early as other places.
Water used for agriculture can have negative impacts on the quality and quantity of water left for the rest of the world to use.
Certain irrigation practices conserve water better than others. Drip irrigation is the most water-efficient method because users can control how much water they use, and water goes directly into the soil. However, drip irrigation isn’t very scalable. It is time-consuming to set up, requires more attention, and isn’t the most cost-effective. Whereas a rotating sprinkler system requires less work and can cover large areas, however about 35% of the water evaporates and doesn’t actually water the crops.
Streamflow impacts fish migration and spawning patterns, as well as how much water is available for people to use. Dams and canals installed in rivers to help with irrigation change the river’s flow, leaving less for everyone else. They can also cause habitat loss and even erosion.
Ranchers and livestock also impact water resources. The meat and dairy industry is enormous, and its impacts on natural resources show that. Of the water used for agriculture, 23% goes towards watering crops used to feed livestock. Livestock also needs drinkable water, which doesn’t take as large a percentage as growing crops but is still significant. In some parts of the world, cattle grazing causes deforestation, which leads to less water in watersheds because of erosion.
So far, we have only discussed how agriculture impacts the amount of water we have, but it also takes a significant toll on water quality. Both livestock and crops have adverse effects on rivers and other water sources. Contaminated water can cause algae blooms, the destruction of ecosystems, the spread of diseases, and even death.
Runoff pollution occurs when there is an excess amount of water that the soil cannot absorb, and it flows across the earth’s surface, picking up trash, chemicals, waste, etc. It can happen in urban, suburban, and rural areas. Fertilizers and pesticides applied to crops find their way into the water supply, contaminating the water and making it unsafe to drink unless it’s treated. According to the National Water-Quality Assessment, agriculture runoff is the number one thing that impacts water quality in rivers and streams.
“About a half million tons of pesticides, 12 million tons of nitrogen, and 4 million tons of phosphorus fertilizer are applied annually to crops in the continental United States,” the EPA stated. “Soil erosion, nutrient loss, bacteria from livestock manure, and pesticides constitute the primary stressors to water quality.”
Animals confined in small spaces also produce a concentrated amount of waste that can potentially end up in rivers because of runoff. Roaming livestock that have been sprayed for ticks or other pests often wade or bathe in rivers, also contaminating the water supply and killing its inhabitants.
Entire communities need their local rivers in order to support their energy, water, outdoor recreation, and agriculture sectors. Putting the needs of people aside, plants and wildlife also depend on these rivers to survive. Rivers are expected to support the needs of so many different aspects of society, and they often have competing interests. For example, some ranchers also own a flyfishing business; both need water from the river, and both impact its health in different ways. With lives and livelihoods on the line, the politics surrounding rivers can be tense, but with so many people depending on the river, everyone is invested in protecting it.
The Colorado River is an excellent example of a resource supporting more than is able. About 80% of the Colorado River is used for agriculture. This is an instance where most of the water used by the river goes towards crops meant to feed livestock. In the 20th century, the volume of water in the Colorado River has decreased by 20%. Demands on the river have remained constant and have increased due to the rising popularity of outdoor recreation. At this point, because of the decrease, more water is being allocated than is available. Everyone is taking their share, but their shares are now too big.
The good news is that with so many people who have a stake in the river’s health, the majority want to protect it. The Nature Conservancy works with farmers and ranchers on various projects to help the river. Whether it’s changing their farm infrastructure, getting paid to temporarily forgo water use, improving irrigation practices, or even switching to growing crops that need less water. These represent a fraction of the projects taking place to protect and restore the Colorado River.
The Colorado River is just one example of many. There are rivers all around the world that are just as vital and either are or will find themselves in a critical condition. Agriculture plays a huge role in the health of rivers and is arguably what impacts them the most directly. However, they also need the rivers more than anyone else. Making them the perfect stewards because they have the most desire for change, and are the ones most likely to make it happen. Shifting how we view farming and breaking away from tradition by changing farm infrastructure and practices will be a huge step for the future of river conservation.