It's part of a larger corporate wave that's turning Japan from a land of rigid, high-cost lifetime employees into a nation where skilled workers migrate with jobs.

FORBES: Greasing the wheels

Workers may migrate, but their pension plans do not.

ECONOMIST: European pensions

And though WaterHealth makes sure that there is someone in place locally who can maintain its systems, Jody Camp, a manager at the nonprofit Water For People, argues that such skilled workers often migrate to better wages elsewhere.

FORBES: Running dry

Workers found it more worthwhile to stay in third tier cities than to migrate back to tier 1 cities on the coast, said Ira Kalish, a director of global economics at Deloitte.

FORBES: In Coastal China, A Labor Shortage