4th set of human remains found in Lake Mead

Human remains were again found in Lake Mead, the country's largest reservoir that continues to shrink amid a decades-long drought, officials announced Sunday.

According to the National Park Service, someone made the discovery at the park's Swim Beach in Lake Mead National Recreation Area, on the Nevada side, around 11:15 a.m. Saturday. This marks the fourth time since May that human remains were found in Lake Mead, where water levels continue to recede at historic levels.

With the help of the Las Vegas Metropolitan Police Department's dive team, park rangers responded and set up a perimeter to retrieve the remains, the NPS said.

Officials have said the reservoir's water levels are so low they could hit "dead pool" status, which means that the water is too low to flow downstream.

The minimum water surface level needed to generate power at the Hoover Dam is 1,050 feet, according to the U.S. Bureau of Reclamation. Anything below that is considered an "inactive pool," and a "dead pool" exists when the water level hits 895 feet, according to the federal agency.

Satellite images released last month by NASA show side-by-side comparisons of Lake Mead, one taken on July 6, 2000, and the other more than two decades later on July 6 of this year.

A result of the diminishing water level is that bodies and human parts have been emerging.

On May 7, human skeletal remains were found near the lake's Callville Bay, according to the National Park Service. The discovery came a week after the decayed body of a man was found stuffed in a steel barrel near the reservoir's Hemenway Fishing Pier, more than 20 miles from Callville Bay, according to the LVMPD.

On July 25, human remains were also found at Swim Beach.

Officials launched an investigation into the most recent discovery on Saturday, and the Clark County Medical Examiner has been contacted to determine the cause of death.

ABC News' Julia Jacobo contributed to this report.