Image produced by Lillian B. Lowengrub on behalf of the Anti-Poverty Network.

If you’re a New Yorker on this rainy Wednesday, you’ll have more than the usual reason to be in a part of the city under the control of public authorities. Also known as the state and local governments, their officials are charged with deciding how people should be held in prison.

There are more than 16,000 prisoners locked up in New York’s jails in the wake of the Port Authority on Superstorm Sandy. That includes a whopping 1,111 inmates from New York City, as well as more than 9,700 from New Jersey. Together, these cities make up more than a third of the jail population in the entire state. If a crisis that affected New York City — a situation involving the city and its region, not an illness spreading beyond the city — drove up the number of men in jail, the choices would be not much different from the ones already on the table: release them, move them elsewhere, or treat them like criminals.

In the last few years, there has been a shift away from mass incarceration. As those numbers have dropped, New York City and New Jersey have expanded their responsibility. The facility where the plan for housing inmates from New York is housed on Rikers Island was built for 1,600 inmates.

But the low number of men in jail — and the fact that New York City has fewer men in jail than the next city in its region — cannot insulate the current plans for housing inmates from legal and constitutional scrutiny. New York’s case is particularly serious because most of the men are still in jail without any obvious crime to justify their prolonged confinement.

How does a crisis involving New York City — a situation involving the city and its region, not an illness spreading beyond the city — drive up the number of men in jail?

New York’s detention policies matter for a number of reasons. Prisons and jails are designed to keep prisoners safe from criminals as much as from other prisoners. New York is not the only place where prison populations grow when people are facing imminent release from jail — America has, by far, the highest number of people in prison per capita of any nation. We also are increasingly warehousing people in decrepit facilities, neglecting health care and making elaborate efforts to suppress the outside world.

In the last six years, upstate New York has lost 50 percent of its municipal and county jails because of disastrous consequences like the December 2015 floods. The vast majority of the people remaining behind bars are people of color who experience disproportionate levels of legal and social harms compared to their white counterparts. New York City’s criminal justice system is one of the most unequal in the country, yet the mayor who insisted on the need for universal pre-K after the 2015 storms is resisting calls to require all city jails to offer it.

President Trump suggests he plans to spend less than $2 billion to replace the New York City facility where the planning is taking place. Some might argue that such an expenditure would be justified — after all, the president’s proposed budget asks taxpayers to pay $7.3 billion to build a big new prison for nonviolent drug offenders. In recent years, Manhattan prosecutors have made hundreds of millions of dollars defending themselves in court, while offering thousands of financial inducements to potential witnesses and defendants. A $2 billion question for New York’s public authorities: what is the public purpose of having another jail?