Somerville is preparing for an innovative project aimed at easing flooding and water pollution from heavy rainstorms and creating a long-awaited new park near Union Square.

The $92 million venture involves constructing a stormwater pump station on the Poplar Street site of a former trash transfer station and then converting the remainder of the 2.2-acre site into an agriculture- and arts-focused park, according to Richard Raiche, Somerville’s director of infrastructure and asset management.

The $80 million station is targeted to break ground this fall, provided the City Council authorizes the needed borrowing — to be repaid by ratepayers. A later council debt authorization is also needed for the $12 million park. But Raiche is optimistic councilors will approve both measures.

The plan received a boost when US Representative Ayanna Pressley, of Boston, secured $2.5 million for the plan in federal budget funds.

Officials said the project would enable Somerville to meet new federal stormwater discharge requirements while also realizing a years-long dream of creating an “ArtFarm.”

“I can’t overstate my enthusiasm for this project. This is solving a problem that has been with the city for 150 years,” Raiche said of the need to prevent stormwater-related flooding and pollution. “We are in a position to solve it right as these problems are being exacerbated by climate change. And the new park is something the community has wanted for a long time.”

Gregory Jenkins, director of the Somerville Arts Council, said many residents would be thrilled to see the vision of the ArtFarm — now coupled with another vital municipal need — finally become a reality.

“The combination of arts, public infrastructure, and open space in a neighborhood that is going to be changing rapidly and evolving with new development will be great for the city,” he said.

Discussion of a possible art farm began after the private trash transfer station that had operated on the city-owned site closed and was demolished in 2013.

Since then, small-scale crop-growing and arts activities have occurred on the property. The new park would provide permanent facilities for those uses, including a barn-style building for indoor music, dance, and other performances, a plaza for outdoor performances, a greenhouse, community gardens, and open landscaped areas.

Raiche said Somerville added the pump station to the project in 2017, when it learned of the opportunity to discharge stormwater into a drainage system the MBTA was updating along the rail corridor in which it was extending the Green Line.

Somerville’s 1870′s-era sewer pipes carry rainwater runoff in addition to sewage. Because such combined systems can result in untreated sewage discharging from sewer drains during heavy rainstorms, federal rules are requiring communities to separate their sewer and stormwater systems.

Raiche said Somerville has begun installing separate drain lines near Union Square, but currently lacks a way to discharge the stormwater outside of the sewage treatment system. The pump station would solve that by allowing the city to pump stormwater over a hill to connect with the MBTA’s drainage system..

The station would include a 4-million-gallon underground storage tank — for use when stormwater flow exceeds its pumping capacity — and two small buildings to filter stormwater debris and remove phosphorus if needed.

The project would ease chronic flooding in the Union Square area and reduce risk of polluted water from sewage overflows entering the Mystic and Charles rivers, Raiche said.

“We are so pleased Congresswoman Pressley and the city of Somerville are making this investment in a healthier community and a more resilient watershed,” said Patrick Herron, executive director of the Mystic River Watershed Association.

“For us, an art farm is kind of quintessential Somerville — engaging artists and creating a new public space,” he added. “To have that set of benefits along with such an impactful project makes this such a wonderful initiative for the community and regionally.”

John Laidler can be reached at laidler@globe.com.

Work at Boston Globe Media