Peter Katz, a nationally recognized expert on 'new urbanism,' has resigned from his position as Arlington County planner, effective Tuesday.

Katz started working for Arlington on Oct. 11. He wrote in his resignation letter that he wasn't a good "fit" for the county.

"Recognizing Arlington County's long tradition of visionary planning, and its desire to build on past successes, I was honored to bring my skills and experience in the realm of Smart Growth planning and implementation to the position of Planning Director last October," Katz wrote.

"Despite our mutual efforts over the past few months, it seems that we are now unable to achieve the optimal 'fit' to best advance the goals of the division."

Robert Brosnan, director of the Arlington County Department of Community Planning, Housing and Development, said in a statement that the county will take immediate steps to fill the position.

"Peter Katz is a well-known proponent of the New Urbanism (smart growth) movement, and has played a key role in shaping the movement," Brosnan stated.

"Peter and we have come to a mutual agreement that his passion and energies are better suited to consulting than to staff work. Though we both worked hard to make it work, it just ultimately wasn’t the right fit, which we regret."

Katz was hired at an annual salary of $150,000.

This story has been edited to correct the spelling of Robert Brosnan's last name.