BATAVIA — As the city’s population declines and the percentage of seniors increases, the growth industry is low income senior housing, with an additional 79 units now under construction.

Millions of dollars will be spent on DePaul’s 43,000- square-foot apartment complex on East Main Street, and the conversion of two top floors of the former St. Jerome Hospital into The Jerome Center’s one-and two-bedroom units that will tower over downtown Batavia.

DePaul’s 42 units, slated for completion in January, are being built by a Rochester human services agency. It will include housing for the elderly, mental health residential and treatment residents, and support services for developmentally disabled. A state housing agency is a sponsor.

The Jerome Center will accept low and moderate income seniors in a building that already houses outpatient treatment and diagnostic services, as well as a cafeteria and gift shop. The former hospital is now a part of United Memorial Medical Center, whose main campus is the former Genesee Memorial Hospital.

Low income housing has a long history, dating to the early 1970s when a municipal housing authority erected small apartment buildings for 12 to 20 families at three sites. The largest projects—largely for seniors— are Four Hundred Towers on East Main Street with 150 apartments built in 1971, and Washington Towers overlooking downtown, which opened in 1982 with 131 residents. About the same time, Birchwood Village for families, many with children, opened on Pearl Street.

The flurry of activity for both groups — low income families and seniors — followed the demise of local industry. Thousands of blue-collar jobs were lost with little likelihood of new industry.

The city’s population for some time hovered around 20,000, but today has dropped to 16,000. Meanwhile, the percentage of those 65 and over has risen to an estimated 25 percent.

More recent housing helps low income, senior and handicapped people with rent subsidies based on income. The first was the Monsignor Kirby Apartments, 37 units near the Thruway exit.

In 1999, the Genesee Valley Rural Preservation Council built the Genesee Park Place Apartments on the city’s western border. Six years later, the nonprofit group built the Havenwood Congregate Apartments on the Batavia VA Medical Center property. Both are 36 one-bedroom facilities with state funds involved in the construction. Rents are subsidized based on income.