Mayor Martin Walsh on Tuesday announced funding for 10 affordable housing developments across Boston, a nearly $22 million investment to preserve or produce 602 housing units. Dorchester and Mattapan projects account for half of these approvals, bolstering several longstanding large mixed-income developments.

“Preserving Boston’s affordability is key to ensuring everyone who wants to live here can afford to do so, and I’m particularly pleased this funding will both preserve and add to our existing affordable housing stock,” Walsh said. “This will help us continue to build a pipeline of affordable housing, and put us one step closer towards reaching the ambitious goals laid out in our housing plan.”

The Hearth at Four Corners project, developed by Hearth Inc. on city-owned land, will create 54 units of affordable housing for elderly residents as several income points. It includes 16 units set aside for extremely low income elders.

Wilshire Apartments on Cheney Street is a rehabilitation and refinancing effort for an existing 29-unit, Section 8 project. The non-profit Urban Edge plans to preserve the existing Section 8 contract for the site.

One of the larger projects is the Indigo Block at 65 East Cottage St near Uphams Corner. Boston Capital, Escazu Development, and Dorchester Bay EDC will develop the city-owned site, set to include 89 units of housing. The development will comprise of 80 units of low-, moderate-, and middle-income rental housing; 9 market-rate ownership units; and a light industrial commercial building.

Another mixed-use housing project, the Four Corners Plaza development, would rise along Bowdoin Street. Codman Square NDC is proposing a mixed-use, affordable housing development including a four-story building with 28 affordable rental units and a 9,920 feet of commercial/retail space.

Developers also plan three affordable rental townhomes with 40 parking spaces total.

Olmsted Green Phase IV on the former Boston State Hospital site in Mattapanis poised to be the home of a 47-unit mixed-income rental development, developed by Lena New Boston.Funding for these and five other projects is facilitated by more than $13 million from the Department of Neighborhood Development (DND), and more than $8 million of linkage funds awarded through Boston’s Neighborhood Housing Trust.