Parts of Grand Canyon will be visible for first time in decades. Experts explain why

The water flow in the Grand Canyon is temporarily changing and it could reveal some surprises, geologists said.

The U.S. Geological Survey said Sunday that an 11-day “spring disturbance” flow will start Monday and will drop water levels in parts of the Grand Canyon.

During that time, geologists will reduce the flow of the water released from Glen Canyon Dam, a popular tourist destination where people can take tours within the national park.

“Water released from Glen Canyon Dam will drop to 4,000 cubic feet per second, less than one-third the average rate of water released this time of year,” the USGS said in a Facebook post. “The streamflow will remain low for five days to allow a Bureau of Reclamation dive team to conduct routine maintenance to the dam.”

While dam maintenance may not seem exciting, the drop in water could reveal parts of the Colorado riverbed that hasn’t been seen in decades, USGS said. It could also impact in the Colorado River ecosystem.

The change in water levels will also mimic what the Colorado River was like before the dam was built, USGS said.

“The Colorado River experienced seasonable variable flow rates, including springtime flooding events,” USGS said. “These spring floods scoured the river bottom and enhanced natural processes that sustained the Colorado River ecosystem.”

The dam was built in 1963. Since that time, floods during the spring have become increasingly rare.

“Now, after more than 50 years of operation, the apron (underwater portion) of the Glen Canyon Dam requires maintenance,” USGS said. “This combination of low and high flow disturbance is expected to enhance the natural processes that sustain the Colorado River ecosystem by mimicking springtime pre-dam flooding.”

The USGS will give daily updates of their findings from Monday until March 26.

“Our researchers will be out on the river before, during, and after the spring disturbance flow collecting aquatic insects and plants,” USGS said. “We will be taking a series of repeat photos to determine how aquatic plants change now and in the years to come.”