Donald Guter, dean of the South Texas College of Law—Houston, has spent the past several days volunteering at the George R. Brown Convention Center, which has transformed into an emergency shelter for people displaced by flooding from Hurricane Harvey.

Guter counts himself as fortunate. His downtown Houston high-rise apartment building has been spared from the rushing water, and sits several blocks from both the convention center and the law school, each of which have escaped flooding. Guter and his wife started working at the shelter Sunday night, soon after it opened. But by Tuesday afternoon they were turned away due to an oversupply of Houstonians who had showed up to help. Only volunteers with medical backgrounds were let in.