One more factor, urban specialists said, is the collaboration Des Moines has built into its governing practices to avoid civic wars that can delay projects. Moreover, virtually all of the city’s new private projects, including the Wellmark building, were assisted by city tax funds. Richard A. Clark, the city manager, said Des Moines had invested an average of nearly $2 million annually in public dollars over the last several decades to help businesses assemble parcels of land, improve streets, build parking structures and other infrastructure. The public money has leveraged over $2 billion in private investment downtown since the 1990s, he said.

Des Moines even spends $250,000 in tax revenue annually to support public art. Its hotel-motel tax contributes $740,000 annually to a $2.45 million regional account that the city shares with seven suburbs to support the zoo, a civic center, a botanical garden, a symphony and other cultural institutions.