Plymouth’s Water Street Promenade Project calls for a radical makeover of the historic waterfront that its backers say would make it shine for the celebration of the town’s 400th anniversary.

But some residents, including Town Meeting members, say it’s the wrong time to be spending nearly $17 million on work the town doesn’t really need, when serious infrastructure needs are piling up.

“You just can’t have everything you want,’’ Town Meeting member Alan Costello said recently, citing taxpayers’ uncertainty over, among other things, the financial impact of a major repair to Plymouth’s sewer system.

Opponents narrowly defeated funding the promenade project at Town Meeting in October. But selectmen, fearing the loss of a state grant, called for another Town Meeting on Dec. 6 to reconsider the funding question.

The job of winning approval appeared to have become more difficult in recent days, however, when hopes of receiving a state sea wall reconstruction grant fell through, dashing the town’s chances of gaining 20 percent of the project’s total cost from state funding. The town received a $1.7 million economic development grant from the state, but needed the sea wall grant as well to reach the 20 percent threshold.

“The Board [of Selectmen] made a commitment to Town Meeting not to move forward unless 20 percent of the project was provided by outside sources,’’ Selectman Anthony Provenzano said on Nov. 30. As a result, the board won’t formally back town funding now. But speaking for himself, Provenzano said he still supports a “yes’’ vote by Town Meeting to move the project along in time for the 400th.

The waterfront has been waiting a long time for attention, project planners contend.

“It’s night and day,’’ public works director John Beder said of the difference the project would make to the look and feel of a tourism gateway stretch along Water Street where no substantial changes have been made since the 1930s.

The project calls for replacing a ­Depression-era sea wall to protect the harbor against rising sea levels, significantly widening the current Water Street walkway, improving sightlines, and adding plantings, seating, a shade pavilion, and a boardwalk to complete an attractive, comfortable pedestrian connection between Plymouth Rock and the working harbor at Town Wharf.

Town Meeting had approved the project in its planning stage, Provenzano said, and it represents the final part of the town’s efforts to take the entire waterfront to a new level — and in time for the festivities celebrating Plymouth’s founding in 1620.

In accord with the town’s vision to beautify the waterfront for 2020, the traffic rotary on Water Street has been replaced by an attractive “roundabout.’’ Infrastructure improvements have also been made to the south end of Water Street from State Wharf (home of the Mayflower II replica ship) to Sandwich Street, widening sidewalks, adding textured crosswalks, and improving pedestrian safety around Plymouth Rock.

A substantial reconstruction of Town Wharf north of the sea wall has improved public access to a pier used by fishing boats and harbor cruises, and has made the wharf work better for both businesses and the public. Improvements have also been made in Brewster Gardens, the park that connects Main Street to Water Street, including a new footbridge over Town Brook, officials say.

They said the promenade project, the final phase of the makeover, is costly because any construction near water must meet environmental standards.

“Any tie-in next to the water is expensive,’’ Beder said. “Marine sea walls are expensive.’’

The new walls are being planned for “coastal resiliency’’ in the face of rising sea levels, Beder said, and would increase flood protection from the current 11 feet to 15 feet above sea level.

“Basically, we want to prepare this section of the waterfront for a storm,’’ he said.

But when the plan came before the Oct. 21 Town Meeting for funding approval, it failed to get the required two-thirds majority by a single vote. Opponents said they feared a spending binge.

Costello said that fiscally conservative Town Meeting members like himself remain in the dark about the impact on taxpayers of the cost of replacing the sewer system’s force main pipe, which failed two years ago. The cost is estimated at $50 million.

Stacey De La Cruz said the sewer pipe failed the same week she bought her house on Braley Road. She said she likes the waterfront improvement project, but that the timing is poor.

“We have a looming debt over our head,’’ she said. “They’re trying to put it down our throats. It’s irresponsible.’’

Besides the sewer system fix, the town has borrowed significantly to pay for two new high schools, one of them replacing a school that lasted only 28 years.

“They don’t put a dollar into maintenance,’’ Costello said. “Everything’s a crisis, and then you have to replace it.’’ He said Town Meeting has also been told of plans for a new fire station and new fresh-water wells.

“There’s a lot of uncertainty about continuing to spend,’’ he said. Town Meeting members are “starting to put the brakes on. . . . It’s getting too high.’’

Costello said the no votes at Town Meeting came less from opposition to the promenade project’s cost —estimated to add $66 a year to the average tax bill — than from concern over the cumulative impact of the town’s spending and borrowing.

He said his property tax bill has increased significantly since he moved into town a dozen years ago. His opposition has hardened in the face of selectmen’s decision to bring the project back for another vote.

“It sets a bad precedent,’’ Costello said. “It disenfranchises all those that did vote.’’

Selectmen said they called for a new meeting because three Town Meeting members said the town’s electronic voting system failed to record their “yes’’ votes in the 81-to-41 vote that narrowly missed the two-thirds mark. But opponents contend that a reconsideration vote, in which the yes total declined by nine votes, has already addressed that problem.

Selectmen argue that confusion over the vote and the prospect of losing the $1.7 million grant justify the new Town Meeting.

As for taxpayers’ worries over spending too much on the waterfront, Provenzano said the improvements will pay for themselves. “There is a lot of untapped value in the private parcels along the waterfront,’’ he said.

Provenzano also said that repayment of old loans coming off the town’s books will minimize the impact of new loans. And a more attractive waterfront is likely to leverage tourism dollars in 2020. “The eyes of the world are going to be upon us,’’ he said.

A hundred years ago, Plymouth cleared away its working wharfs to return the waterfront to something like the natural state the Pilgrims encountered in 1620. Now is the time to improve the area and “take it to the next level,’’ Provenzano said.

Robert Knox can be reached at rc.knox2@gmail.com.