Her dog died in a storm drain near an O.C. dog beach. Now, she’s trying to warn others to stay away

Madi McNaughton and her three dogs had played often along the stretch of sand between Newport and Huntington beaches — known in recent years as a place pups could, unofficially, run off leash.

But the 24-year-old, in search of a calmer place to enjoy the ocean, last week decided to try a spot east of the dog beach. She had seen people with their dogs and children in the area just past the Pacific Coast Highway overpass before, and figured it was a safe place to toss a ball.

That’s where her 3-year-old mastiff mix, Rupert, drowned after getting pulled into a storm drain.

“It was the worst day of my life,” the veterinary assistant said.

The spot, which is in fact a flood-control channel, is appealing to many people because the water tends to be calmer farther away from the waves.

“It may look inviting, but it’s still … dangerous,” Orange County Public Works spokesman Shannon Widor said.

According to McNaughton, she had tossed the ball and Rupert bounded to retrieve it. As soon as he reached the toy, the tide came in and water began pushing him toward a drain on the side of the Santa Ana River bed.

The current was strong and Rupert was moving quickly, so McNaughton jumped into the water and swam toward the 150-pound dog.

“I grabbed the top of the drain and reached in right as he was going under [water] to grab his collar,” she said.

As her left hand clutched Rupert’s collar, her right hand gripped the top of a concrete wall.

“My arm was completely stretched out and I couldn’t breathe because the water had started going over my head,” she said. “I had to let go of his collar because, if I didn’t, I would have been sucked in after him.”

She scrambled out of the water and rushed to the other end of the drain to find that it was covered by a metal grate, preventing Rupert from passing through.

“He got stuck,” she said. “I stood there at the grate for three to five minutes, just hoping to see some sign of him. I knew there was no way he was still alive. I was hysterical at that point.”

McNaughton got Rupert from the Baldwin Park shelter when he was 3 months old. “He was just a gentle giant,” she said. “He was the happiest dog.”

Ten minutes after Rupert disappeared, his large body washed out of the drain.

For years, signs have been posted near the bike path that runs above the area, warning people to stay out of the flood-control channel. But for pet owners walking from the dog beach to the other side of the PCH overpass, there was no indication of the danger, McNaughton said.

So she has posted fliers — featuring photos of Rupert — by the drain and along the bike path as a warning to others.

County crews also have put up orange temporary fencing in the area. In coming weeks, crews will install a more permanent barrier and additional signs to dissuade people from entering the flood channel.

They also are investigating why there was no grate on the side of the drain where Rupert went in, Widor said. The absence of a grate allowed his body to flow inside.

“We’re doing everything we can to make sure this doesn’t happen again,” Widor said.

hannah.fry@latimes.com

Fry writes for Times Community News.