A lasting solution to flooding at Vineyard Haven’s infamous Five Corners remains a distant prospect, with state engineers this week unveiling a stopgap plan to divert and trap some stormwater further upstream from the chronically swamped intersection.

In an online presentation to about three dozen people Monday night, state Department of Transportation officials outlined plans to install a 150,000-gallon underground infiltration system uphill from the intersection. The drainage system is planned to go beneath the town parking lot at 21 Beach street, where the downtown fire station was demolished nearly a decade ago.

Though the project is estimated at $1.7 million, Five Corners will still require a future project of its own to deal with the flooding, said MassDOT project manager Hung Pham.

“This really is a Band-Aid approach,” Mr. Pham said.

The state’s design has a series of plastic tanks, nestled in crushed stone below the lot’s paved surface, where stormwater will be filtered and then allowed to seep naturally into the sandy soil. Additional catch basins and pipes will redirect stormwater from Causeway Road to the Beach street lot, according to the plan.

The estimated $1.7 million cost of the project, expected to begin in 2024, will be shared by the state and the Federal Highway Administration, Mr. Pham said.

The entire system can filter and slowly release the equivalent of six inches of rain on an acre of land, said MassDOT engineer Lindsey DiTonno. It’s the largest installation the Beach street property can hold, she said, and should alleviate some Five Corners flooding in stormy weather.

But heavier rainfalls are likely to bring more stormwater than the system can filter, Ms DiTonno said.

Keeping the critical five-way intersection dry in all conditions will require more study for a future project, according to the DOT staffers, who detailed the site’s complications.

“Dense development and the creation of impervious surfaces over time has been a contributing factor to the increased rate and volume of storm runoff that enters the harbor through the existing drainage system…Water is really being forced toward the Five Corners,” Mr. Pham said.

That includes runoff from neighboring properties that should be taking responsibility for their own stormwater, according to Ms. DiTonno.

“It’s really shocking how many private properties are draining into this without treating [runoff] on their own,” she said.

While quick to flood, Five Corners is painfully slow to drain. An outfall pipe leading down Beach street extension to the harbor is regularly clogged by shifting sand, while the low-lying intersection doesn’t provide enough slope for the pipe to push stormwater against incoming tides, Mr. Pham said.

But simply extending the outfall pipe far enough into the water to both avoid tidal silting and achieve a positive flow from land to sea would jeopardize boater safety in the busy harbor, he said.

The state is planning a separate study on Five Corners drainage and recently issued a request for proposals from specialist firms to tackle the problem.

One possible solution, according to Tisbury town officials, may lie in reviving state licenses previously issued to the town to develop a drainage corridor along Lagoon Pond Road.

Town officials and residents at Monday’s presentation lodged no objections to the Beach street project, which Mr. Pham said he will bring back for further review once it goes through additional design work.