Stephen Curry plans to visit a West Oakland elementary school next month, but the Warriors superstar and idol to kids everywhere won’t be promoting three-pointers.

He’ll be pitching water filters — an arrangement that critics say raises questions about the insinuation of advertising into schools.

Curry is scheduled to visit Martin Luther King, Jr. Elementary School on March 8, appearing at a school assembly planned and promoted by Brita, which sells a variety of water-filtration products. The subsidiary of Clorox signed a three-year endorsement deal with the Warriors’ point guard in December.

Brita is inviting reporters to the assembly, in hopes of generating news coverage that would reach an even larger audience.

The appearance is linked to a national “Drink Up” campaign that encourages water consumption rather than sugary alternatives. The effort is sponsored by numerous for-profit companies that sell water or water products, including Brita — and encourages supporters to buy the sponsors’ products online.

While many sports stars visit schools, most do so independently or while aligned with a nonprofit organization or educational activity. Curry’s appearance is directly tied to a company and a product he’s being paid to endorse.

That’s a problem, said Josh Golin, executive director of the nonprofit Campaign for a Commercial Free Childhood, which is based in Boston.

Branding is the problem

Events like this “are really designed to get kids to go home and nag their parents for the water filter Steph Curry is telling them to buy,” Golin said. “I would absolutely say if this was a nonprofit promoting water consumption I would have no problem with it. It’s the branding” that is problematic.

Schools have long been considered fertile ground for corporate marketers. Branding efforts have included product placement in textbooks, company logos on donated scoreboards and sponsorship of school events.

In recent years, though, many school districts have beefed up policies to prevent such activities from penetrating campuses and class time.

In Oakland, district officials said Wednesday that the Curry appearance does not violate a district policy.

While school officials are mindful of potential exploitation, the benefits of having Curry visit the school and encourage children to make the healthy choice of drinking water is a good thing, said board member Jumoke Hinton Hodge, who represents West Oakland.

“I think they’re going to hear Steph Curry say drinking water is good for you,” she said. “I can’t find a problem with it. I’m OK with it. I’m very OK with it.”

Isaac Kos-Read, a district spokesman, said, “We’re excited that a world-class athlete such as Steph Curry has chosen to highlight the healthy option of drinking water, and that he’s doing so at one of our West Oakland schools.”

Curry has in the past two years become one of the most marketable athletes in the world, with an estimated $10 million in annual endorsement deals. He said he chose to sign with Brita because he wants to promote water rather than soda or sports drinks.

Curry chooses water

“Drinking water is essential to a healthy lifestyle,” Curry said in a statement announcing the endorsement deal. “Water is my drink. I like that Brita makes tap water taste good, so you don’t need to spend money or waste plastic with bottled water.”

Jennifer Harris, a food marketing researcher at the University of Connecticut’s Rudd Center for Food Policy and Obesity, noted that there is “a lot of marketing in schools and most of it is for soda and candy, sports drinks and fast food. Water is better than all of those things.”

However, she said, Brita is pitching a product to school kids through one of their biggest heroes.

“A lot of companies want to be there, because where else could a company reach every child in that neighborhood?” Harris said. “In this case it’s just pure marketing.”

Marketing in schools is a corporate no-brainer, said Faith Boninger, an expert in commercial activities in schools at the National Education Policy Center in Boulder, Colo.

In October, when actor Jack Black visited a Minnesota school to promote his new movie, “Goosebumps,” school officials showed a preview of the film to students who donned matching “Goosebumps” shirts as local media documented the event.

“Schools provide a relatively uncluttered marketing space, where the child audience is not only captive, but is also … predisposed to be favorable to marketing messages that the children assume the adults who supervise them have approved for them,” Boninger said.

She added that kids “would also be likely to listen to and be favorable toward anything Steph Curry is promoting.”

Brita officials said Wednesday that they won’t be speaking to the students during the event or delivering any commercial messages.

“Beyond promoting Brita products, our relationship with Stephen Curry focuses on reinforcing the benefits of water as part of a healthy lifestyle,” said David Kargas, a company spokesman. “With his help, we can reach more people with the message that water is the best beverage for health.”

Principal Roma Groves said the visit aligns with the school’s effort to promote healthy living in a disadvantaged community

“No more sodas, not even juices,” she said. “We’re promoting water at our school.”

School gets filters

The district said the school is receiving a benefit from Brita, with the company planning to donate and install water filters at the school during the event.

Oakland schools get their water from the East Bay Municipal Utility District, whose supply comes almost entirely from a Sierra Nevada watershed. Officials emphasized there is nothing wrong with the water flowing out of school taps.

Jill Tucker is a San Francisco Chronicle staff writer. Email: jtucker@sfchronicle.com

Twitter: @jilltucker