Story and photo by Sierra Mahoney
At 1,410 miles long, passing through seven states and nine national parks, the Colorado River certainly lives up to its “mighty” moniker. The 277-mile stretch of the river that runs through the Grand Canyon is perhaps its most impressive. Carving a mile deep and up to 18 miles wide, the river began to cut the canyon six million years ago.
The 277 miles of the river running through the canyon starts at Lake Powell, where it flows south and quickly forms Horseshoe Bend. From there, it makes its way further westward through the most famous canyon in the world and the 1.2 million acres that make up the national parkland. Leaving the park as the river continues through the west side of the canyon it ends up in Lake Mead, home to Hoover Dam and on the Arizona-Nevada border.
According to the National Park Service, the formation of Grand Canyon began two billion years ago when the first layers were deposited in the inner gorge of the canyon. Within the past 30-70 million years, the land was uplifted, forming the Colorado Plateau. As the Colorado river began making its way through the land, the water carved the canyon and continues to deepen it today.
The process of forming a canyon is often referred to as downcutting. This phenomenon often happens during flooding and occurs as a river cuts down into the land, causing the rock to erode. According to the NPS’ Grand Canyon site on geology, “When large amounts of water are moved through a river channel, large rocks and boulders are carried too. These rocks act like chisels, chipping off pieces of the riverbed as they bounce along.”
Factors like the steep slope and large volume of the river as well as the arid climate that the river flows through contribute to the vast amounts of downcutting that has occurred to form the canyon.
People have lived along the water for roughly the last 12,000 years, and it has served as a vital source of water and life. For many of the Native American tribes that inhabit the area, the river serves as a powerful resource for agriculture in their communities.
Today, the lower basin also provides drinking water to many major cities located near the river and aids in growing 90% of the nation’s winter vegetables, according to the America Rivers organization. But unfortunately, this poses significant threats when considering the future of the river.
Presently, the river is being overused and more water is being taken out than being put in. According to American Rivers, “Historically, Lower Colorado Basin water users have overcome this supply imbalance by drawing from storage (the combination of Lake Mead and Lake Powell) that accumulated over decades when water demand was lower.”
However, this is no longer sustainable, and drought is proving to be a significant threat to the future of the river. As the planet warms and the river runs drier, the threat to the Colorado River and the 40 million people it serves today continues to increase.