Now the entire beach is one flat field of stone save for its center and at that center a dozen storms have scoured the beach and spread every grain of sand they could find across that same freshwater pond – cutting it in two – and allowing the highest tides free access to the backyards of two homes that were once two hundred yards from the oceans’ reach.

PLYMOUTH – If climate change rearranges a beach and there’s nobody there to see it, does it actually change?

Center Hill Beach gets, on average, about a dozen visitors a day – even at the height of summer.

There are two parking lots for visitors and even the small one on the beach-side of Center Hill Road – about a two minute walk down a pleasant trail from the water’s edge – is never full.

So there’s little fuss about what are, arguably, dramatic changes along this beautiful town-owned beach.

The beach trail that is the easiest way to access the water curls like a question mark, from the parking lot heading first south alongside the road, then curling back around offering a glimpse of a freshwater pond, then downhill and through a thicket of reeds and young trees, over a boardwalk and through an opening into a field of – in the summer – beach rose.

There, just on top of a rocky ridge, you first spy the remnants of a gray, weathered, wooden fence – your private entrance to a classic, rock-strewn New England beach where seals and visitors are often seen sunning themselves on any flat surface they can find.

Or so it was a decade ago.

Now the boardwalk is under water.

Now the trail ends in a debris field.

Now the entire beach is one flat field of stone save for its center and at that center a dozen storms have scoured the beach and spread every grain of sand they could find across that same freshwater pond – cutting it in two – and allowing the highest tides free access to the backyards of two homes that were once 200 yards from the oceans’ reach.

Winter Storm Riley pushed into that space, and filled each of the now two ponds and sent the extra water surging down the historic brook that once - and now again – connected them to Black Pond a mile south of Center Hill Beach.

Houses are at risk. Roads are at risk. People are at risk. The gray, weathered fence that has stood on the ridge at the end of the beach trail is, remarkably, still there but for how long?

Center Hill Beach offers clear testimony in the climate change debate, and relevant data for the debate over where to spend our resources to improve coastal resiliency.

Plymouth acquired this 89-acre $5.6 million piece of property, including a half-mile of public beach, for nothing. Town Meeting originally approved the expenditure of $5.6 million in Community Preservation Act funds to pay for Center Hill Preserve but in the end taxpayers didn’t pay a dime thanks to the state’s matching CPA funds plus other federal and state grants.

Follow Frank Mand on Twitter @frankmandOCM.