The developers of the long-awaited Celestina Gardens Apartments are hoping to break ground on the 40-unit affordable-housing senior complex sometime this fall.

The complex would occupy three-plus acres of the Fetters Apartment complex on Sonoma Highway just north of Mountain Avenue.

MidPen Housing, which also developed Fetters, is waiting to see if it gets an allotment of low-income housing tax credits from the California Tax Credit Allocation Committee. The state grants the housing credits, which are a vital part of affordable-housing developments, in March and again in July. The process is highly competitive and takes into account the portion of public funds committed to the project. Sonoma is competing in the state-wide rural pool for the tax credits.

The project was originally scheduled to start in late 2016 or 2017, but was put on hold until the nonprofit MidPen, could secure the needed tax credits.

Celestina Gardens will have 37 one-bedroom apartments and three two-bedroom apartments, one of which is for the manager.

Ali Gaylord, MidPen’s director of housing development for the North Bay, said if they can break ground this fall, it would take about 18 months to complete the $20-plus million project.

“We’ve spent the last couple of years assembling the finances,” she said.

The agency is working on getting permits from the county. The agency had started the process last fall, but the fire storm in October caused a backup at Permit Sonoma, the county’s permit department.

“We expect to get our permits shortly. And we’ve already submitted our CEQA report,” she said, referring to the California Environmental Quality Act.

The senior complex will be on the northwest side of the site and will occupy a little over three acres. It will include a community garden for the seniors who occupy the complex. It will have a common room, a fitness center, offices and 57 parking spaces.

The development would include eight units for extremely low-income households, 10 units for very low-income households and 21 units for low-income households.

Extremely low-income households are those that have an income of 30 percent or less of the Area Medium Income (AMI); very low-income is defined as having an income of 50 percent of the AMI while low-income is defined as having an income of 60 percent of the AMI.