​The Waters of Hoover Dam: A Timeline

Date: August 9, 2017
Category: Blog

In 2015, a ghost town appeared at Lake Mead. For years, Arizona had suffered through drought, bringing the waters of the manmade lake and the Colorado River at Black Canyon down to record lows. The lake literally hit bottom in June of that year, revealing the ruins of St. Thomas – a once-prosperous railroad town and Mormon settlement that was abandoned in the 1930s to make way for Hoover Dam.

Drive across the newly constructed Mike O’Callaghan-Pat Tillman Memorial bridge and you’ll see a visual reminder of the area’s changing water levels in the high-water mark apparent on every rocky surface. Jokingly called a “bathtub ring,” the revealed stone is lighter in color, with undulating lines marking water heights through the years. If you’re headed downriver towards Willow Beach on our Black Canyon Raft Tour, look for the chalky white rock walls that were once submerged under the Colorado River.

How Did This Happen?

High temperatures, drought and global warming have all been credited for the Colorado’s shrinking waters. According to a recent Associated Press article, scientists Brad Udall of Colorado State University and Jonathan Overpeck of the University of Arizona say that rain deficits can’t possibly account for the 19% drain – at least, not all of it. Research published in the Water Resources Research journal indicated that climate change was largely responsible.

Water Timeline  

As of August 2017, the water level at Hoover Dam was around 1,079 feet, down only a single foot since the same month in 2014. Let’s put the declining water levels in perspective. Lake Mead was filled to full capacity (~1,220 feet above sea level) a few years after the dam was built. Here’s how the high-water levels have fared every decade since (CLICK HERE to view the graph):

1947: 1180.27 ft.
1957: 1184.11 ft.
1967: 1133.85 ft.
1977: 1193.82 ft.
1987: 1210.83 ft.
1997: 1214.65 ft.
2007: 1130.03 ft.
Current: 1,079 ft.

Keep in mind that we haven’t finished the year yet, so this year’s high is likely to be closer to last year’s 1084.46 feet. A drop of a hundred feet over eight decades doesn’t seem like much, but if the trend continues there could be cause for concern. In the meantime, visitors to Hoover Dam can explore the recently revealed ruins of St. Thomas and wonder what historically significant landmark could be uncovered next.

See Hoover Dam and the two-tone sandstone walls of Black Canyon on a 3-hour excursion offered by Black Canyon River Adventures. For information on the Black Canyon Raft Tour, call 800-455-3490 or visit our website