Water is coming on strong in Yosemite National Park. Rivers and waterfalls tumbling over some of nature’s most spectacular landscapes are an incredible sight.
They also are incredibly hazardous and potentially deadly. The National Weather Service and National Park Service are warning park visitors not to take risks with swift-moving, chilly water.

According to the weather service office in Hanford, the Merced River at Pohono Bridge, within sight of Bridalveil Fall and the Wawona Road vista point, will likely crest above flood stage Thursday night or early Friday. The surging river is expected to flood part of Lower Pines Campground.
The Merced River level also will be hazardous to the base of the swinging bridge, downstream from Chapel Meadow, the weather service said.

Water Accidents are No. 2 Cause of Yosemite Fatalities

The park service noted that mountain water can be deceivingly cold, especially when twinned with warmer air temperatures as summer approaches. Merced River water comes from runoff from a heavy Sierra snowpack; its average temperature in the park is 60 degrees. It someone falls in, hypothermia can set in quickly, making it difficult for even strong swimmer to handle the current, which can pin a person against a rock or other object.
Water accidents are the second most common cause of fatalities in Yosemite (vehicle accidents are No. 1), the park service said. Swimming and wading are forbidden in places such as Emerald Pool, above Vernal Fall, where several accidents occur each year.
If you tumble into rushing water, try to move into a defensive position. Roll onto your back and point your toes downstream.
Better yet, keep a respectful distance from the river and enjoy the views. The Upper Yosemite, Bridalveil and Vernal waterfalls are spectacular right now.