Winter and spring rains put a decent-sized dent in California’s water woes.

In Yosemite National Park, its storied falls are flowing with the kind of force not seen in four years. But the return of torrents of swift, cold water also have park officials concerned about increased drowning hazards.

“The hazard is the water is flowing very swiftly and the bottom has all kinds of entrapments to catch people,” said park ranger Alan Hagman, who heads Yosemite’s rescue operations. “What attracts people to the river is also what will hurt them.”

Amid the park’s stunning scenery, its rivers have claimed lives over the years. Hagman said visitors have gotten too close to the rivers and accidentally fallen in, stunned by the flowing snow melt which runs around 40 degrees fahrenheit. Others have become trapped under logs or dragged away in the blistering currents.

“Swimming is not what most people get in trouble,” Hagman said. “It’s people just going down to fill their water bottle or cool their feet.”

Last week, the park’s Swift Water Rescue Team donned wetsuits and flippers to train in the frigid cold water of the Merced River. They practiced retrieving swimmers caught in the current by tossing them a rope or sending out a tethered rescuer to haul the victims in. But Swift Water Rescue Team director Moose Mutlow said the majority of the occasions when someone gets in trouble, the team can’t arrive in time to save them.

“So if you go in the water,” Mutlow said, “you have seconds to figure out what to do.”

Mutlow estimated 30 percent of the rescue swims he makes are for live victims. The rest are the grim task of retrieving bodies. In 2012, two young brothers were swept down the river to their deaths, not far from where the team was conducting its training session. The year before, three members of a church group were swept over one of the park's waterfalls and died.

“There’s a lot of risk,” Mutlow said, “and that’s why we practice.”

Rather than train in seclusion, Mutlow prefers to make the practices a park event in order to spread awareness of the river dangers. A dry-erase board with “Swift Water Warnings” written on it sat on the Happy Isles bridge where visitors from around the world watched the men in bright yellow helmets take turns floating down the river.

Mutlow said people will often get into trouble posing for photos too close to the river — or posing others too close to harm’s way. He cautioned that the park’s stunning nature can be distracting.

“That’s why you have that little telephoto action on your lens,” Mutlow said. “You could get closer using your camera and you don’t physically have to be next to the water.”

With the falls in full swing, coupled with the National Park System celebrating its centennial, Yosemite is expected to draw record numbers this year. Rangers advised avoiding peak hours and weekends to avoid the large crowds. Mutlow said the message was to enjoy the park, but give nature a little space.

“I think the best stories are the ones you get to tell yourself,” he said.