Though unheard-of in the United States, supervised injection sites have existed in Europe for years — one of the first was in Switzerland, 30 years ago — and in Vancouver, British Columbia, the only city in North America where the practice is allowed. They have been linked to a reduction in harm from heroin abuse: In Vancouver, fatal overdoses dropped 35 percent in the community surrounding its main injection site in the two years after it opened in 2003 and fell 9 percent citywide.

Image Buffalo Street in Ithaca. In a span of a week and a half in 2014, there were more than a dozen heroin overdoses in the city, three of them fatal. Credit... Heather Ainsworth for The New York Times

Here in Ithaca, a city of 30,000 in the Finger Lakes region, there were more than a dozen heroin overdoses, three of them fatal, in a span of a week and a half in 2014, shortly after Mr. Myrick appointed the committee that proposed the injection center. The Tompkins County Health Department does not break out overdoses by municipality, but in 2014, the most recent year for which data is available, there were 14 fatal overdoses in the county, where Ithaca is the only city.

The proposal for an injection facility, part of “The Ithaca Plan: A Public Health and Safety Approach to Drugs and Drug Policy,” would require changes to a number of state and federal laws, according to state health officials.

Gov. Andrew M. Cuomo, a Democrat who has mounted a forceful response to the heroin epidemic, told reporters at an unrelated news conference recently that he was unfamiliar with the details of the Ithaca plan and would not offer his opinion.

Much of the Ithaca drug plan has been embraced by a cross section of the community. The plan calls for more drug education, both for children and adults; improved mental health screening; a detoxification center; and a methadone clinic. But the supervised injection program has divided local law enforcement officials.

Ithaca’s police chief, John R. Barber, said he could not support the proposal because “right now, heroin is considered an illegal substance under the law.” But Gwen Wilkinson, the district attorney for Tompkins County who helped lead the committee that formulated the plan, said after its release that she was “prouder than ever to be an Ithacan.”