e traded a cushy bank job for a down-and-dirty pool construction gig, but Randy Mendioroz never forgot the basics of business. Today, the aquatics designer is known for making clients understand a project’s bottom line — even if it means losing them in the process.

But Mendioroz, principal of the Aquatic Design Group in Carlsbad, Calif., wasn’t always calling the shots. He began his aquatics career excavating and guniting pools.

Later he combined his experience as a stock boy with his studies in business and accounting, and became the operations manager at California Pools. He then moved to the company’s commercial division, where he specialized in 50-meter pools at universities and high schools. Not long after, he was named head estimator and project manager.

In 1984, he started his own business designing waterparks, with his first project being Wild Waves Waterpark in Federal Way, Wash. Four years later, he formed Aquatic Design Group.

Though Mendioroz’s focus is designing, he never forgets the business angle. “We started our practice in the private sector … so we’re used to designing for clients who make money,” he says.

With more than 2,000 projects in 25 years, some of his clients include Disney, Six Flags and Universal Studios. Over the years, he also designed and built a $35 million waterpark in South Africa called the Lost City, which he considers one of his biggest accomplishments.

But it’s designing for profitability and cost recovery that he’s most proud of.

“I think that’s what’s unique about what I do for my clients … to make sure their facility not only gets built, but is operated and maintained as close to break-even as possible in the public sector,” he says.

His other focus is improving the quality of his work and constantly studying hydraulics, structures, hazardous materials, environmental health issues and water chemistry. He tries to implement “green” building into his work and constantly researches what’s best for his clients.

Mendioroz, who celebrated his 50th birthday with his three grandchildren, is still in awe of his career. “If you had told me 25 years ago I’d be doing what I do today, I’d think you were nuts,” he says. — Rin-rin Yu