FORT LAUDERDALE, Fla. — With inviting beaches that run for miles along South Florida’s shores, it is easy to put sand into the same category as turbo air-conditioning and a decent mojito — something ever present and easily taken for granted.

As it turns out, though, sand is not forever. Constant erosion from storms and tides and a rising sea level continue to swallow up chunks of beach along Florida’s Atlantic coastline. Communities have spent the last few decades replenishing their beaches with dredged-up sand.

But in South Florida — Miami-Dade, Broward and Palm Beach Counties — concerns over erosion and the quest for sand are particularly urgent for one reason: there is almost no sand left offshore to replenish the beaches.

In these communities, sand is far from disposable; it is a precious commodity. So precious, in fact, that it has set off skirmishes among counties and has unleashed an intense hunt for more offshore sand by federal, state and local officials who are already fretting over the next big storm. No idea is too far-fetched in this quest, not even a proposal to grind down recycled glass and transform it into beach sand. The once-shelved idea is now being reconsidered by Broward County.