WELLS — It was a public hearing in which questions about beach ecology only beget more questions. However, the underlying inquiry from concerned residents of Wells was clear: Why are our beaches eroding, and is adding 375,000 cubic yards of sand a longterm solution?

The solution in question involves purchasing 375,000 cubic yards of sand from a dredging project in Portsmouth Harbor (which Congress is slated to consider later this year) and depositing it on the beach – a process known as beach nourishment. The Board of Selectmen held a public hearing on the proposed purchase on Tuesday and brought state geologist Steve Dickson to explain the science behind the project and answer questions.

A dozen residents spoke about the drastic changes to the coastline that plagues their seaside homes, and expressed concern that comprehensive solutions were not being sought. This redistribution of sand has caused houses farther south of the southern jetty, between Casino Point and the harbor, to lose sand, while houses closer to the southern jetty have an excess that often eclipses their seawall.

Meanwhile in the north, the opposite force is in effect, as houses on the northern edge of Drake’s Island are losing sand while houses south are awash in it as sand becomes sequestered.

Kathleen Scott, a Wells resident living on Atlantic Avenue, told selectmen her seawall was becoming buried, and feared beach nourishment is only a temporary patch on a major problem.

“At one time our sea wall was about 6-feet deep. It’s now about a foot and a half,” she said. “My real concern is this is a temporary fix because it’s not stopping erosion; the sand is still going to erode.”

Robert Wagner said when he bought his house in 1990, he had around 300 feet of sand dunes and vegetation, which successive winter storms destroyed.

“We got a storm that comes through there that’s going to be a good one (and) every single house is going to be underwater. … I hate to see the city spend any more money going further into this project until we hear (it works),” he said.

As Dickson explained, a number of ill-fated engineering decisions over the past 50 years have directly and indirectly caused erosion along Wells Beach and Drake’s Island.

When the jetties around Wells Harbor were constructed in the 1960s, sand began to build up in the protected area where the southern jetty meets the beach. Wave action couldn’t dislodge the sand from the protected, lower-energy zone and deposit it evenly along the rest of the beach, which caused sand to accumulate there until the 1970s, resulting in about 5 acres or 500,000 cubic yards of new sand dunes near the jetty, and a net loss in the beach system.

Those new dunes became protected by the state’s Natural Resource Protection Act and the additional land claimed by property owners, making it nearly impossible to redistribute, wrote University of Maine Professor Joseph Kelly in the Maine Policy Review.

In addition, when Wells Harbor was dredged in 1970, 1971 and 1974, about 500,000 cubic yards were deposited on the salt marsh, and 250,000 yards were deposited on an offshore ledge outside of the beach system.

“When you add that up you’re almost up to about 1.2 million cubic yards of sediment that was once more freely on the beaches in Wells that isn’t there today,” Dickson said. Buying sand “would replace sand that was lost or removed one way or another,” he said.

Between the geology of the beach and the engineering of the jetties, there was little agreement on even the basic erosion issues between residents, selectmen and the geologist.

Selectman Christopher Chase asked why they shouldn’t simply move the sand that has been entering the harbor from the beach system back onto the beach and engaged the geologist in a back-and-forth on whether the sand purchase would be a better solution than simply dredging the harbor.

A report conducted for the Army Corps of Engineers in the 1970s estimated that between 35,000 and 55,000 cubic yards of sand enter Wells Harbor every year, with the jetties creating a protected channel forcing wave action to push the sand in.

“There’s a sandbar in there that I would much rather spend a million dollars picking that sandbar … than adding more to it and creating a further problem,” Chase said.

“You can and you should and you have been,” Dickson said about dredging the harbor. However, by his estimation, the rate by which sand enters the harbor would not increase with the sand purchase, since the flow of the Webhanet River maintains the channels in the harbor to a certain extent, and the sandbar in the middle of Wells Harbor actually prevents a quicker rate of shoaling, or sand accumulation. Dredging would increase the rate by which sand enters the harbor, while adding the sand from somewhere else would not, Dickson said.

“We’re going to have to (dredge) every year until they reconfigure the jetties because everyone knows that the jetties are what’s causing this problem,” Chase said.

“If you were going to take 375,000 (cubic yards) out of the harbor, if that were even possible, it would come back in immediately,” Dickson said.

Beach erosion and the jetties has drawn lines in the community between those who favor the beach and those who favor the harbor, with residents floating suggestions including improvements to the jetty or doing away with it altogether.

One idea sponsored by former Board of Selectmen member John Trafton is the addition of “groins,” or seawall like structures that run perpendicular to the beach into the water. Trafton said they were part of the Army Corps of Engineers’ original plans, and would have prevented much of the erosion and sand drifting into the harbor.

However, Dickson explained that that these structures create the problems that the jetty does in miniature, causing sand to build up in a triangular shape adjacent to the jetty. This would create a “sawtooth” pattern along the beach, rather than a uniform coastline.

Rep. Robert A. Foley, R-Wells, who been a strong supporter of this project, spoke of the need to advance to the permitting and planning stage in order to conduct more studies and ask more questions.

“It always seemed a project worthy of us pursuing. … I urge the board to at least move forward (to that),” Foley said.

The Board of Selectmen voted to schedule another public hearing on taking funds from the Beach Enterprise fund for Beach Sand Environmental Permitting costs.