The Annual What Makes a City? conference will take place from 8:30 a.m. to 12:30 p.m., September 23, at the Dallas City Performance Hall, in partnership with the Trinity Trust. Coffee will be served at 8 a.m. Last year, Dallas Mayor Mike Rawlings asked, “Is it possible to have a park in a floodplain?” Utilizing funds made available by the Trinity Trust Foundation, a team of environmental planners has been working with hydrologists and landscape architects to answer this question. Rawlings, architect Michael Van Valkenburgh and other speakers will speak.

In May, Rawlings unveiled a new concept for the Trinity River Park that includes a naturalized river landscape, fl owing waterways and lush greenery. During the drier seasons, it transforms into a marsh-like waterscape. The concept includes trails and sites for five elevated parks with overlooks that extend from inside the levees into the adjacent communities.

What Makes a City? is conducted under the leadership of Dr. Gail Thomas, president of the Trinity Trust and director of the Institute’s Center for the City. Over the years, What Makes a City? has featured such figures as urban activist Jane Jacobs, organizational analyst William H. “Holly” Whyte, architects Robert Venturi, Charles Moore and Arthur Erickson, and new urbanist Andrés Duany, as well as Dallas leaders.

Cost is $35 for Dallas Institute members; $40 for nonmembers; and $15 for member teachers and Rat Pack/River Rat members. Location: 2520 Flora St., Dallas. For more information, call 214- 871-2440 or visit DallasInstitute.org.