Some of Floridas most celebrated beaches are facing a serious issue: a scarcity of sand. Beaches in Miami-Dade and Broward counties shores are running low on their most characteristic commodity, a situation that has gotten dire in recent years, the Associated Press reported.

Officals typically tap offshore sources of sand that can be used for their beach-replenishment projects, but these sources have been tapped out in both counties, AP said.

Sand -- the small crystals of quartz and other materials commonly found on beaches -- are deposited there by waves carrying the fine sediments to shore. Over time, this fine material is formed by the erosion of rocks, as noted by Discovery News.

Inland erosion that results in sediment being carried away and deposited offshore by rivers is a key element in this process. However, both built-up harbors and dammed-up rivers have greatly affected the process, with one result being less available sand for beach-replenishment projects, as pointed out by Discovery News.

To aid in dealing with the situation in southern Florida, the U.S. Army Corps of Engineers is holding a series of public meetings from Miami Beach to Fort Pierce, AP reported. The effort is vital because new sand sources are necessary to protect Florida’s shoreline from erosion during this and future hurricane seasons.

Beach-replenishment projects in southern Florida have been pretty common since the late 1970s. But it has been a struggle to find sources of sand for Miami-Dade and Broward counties for almost that long. In fact, Miami-Dade officials even began exploring the Bahamas as a source of sand for the county in the 1980s, AP said.

Enough sand exists off southeastern Florida to replenish five of the state’s counties during the next 50 years, but these sand sources are located mainly near Martin, Palm Beach and St. Lucie counties.

As a result, Miami-Dade and Broward counties face major hurdles dealing with the cost of the sand relocation. The federal government and local entities have been splitting the beach-replenishment tab for their beaches. However, the 50-year term of an agreement on budgeting will expire soon for some beach-replenishment projects, leaving them without full funding by the feds.

A bill just passed by the U.S. Senate would extend the agreement for 15 years, and the issue awaits action by the House of Representatives next month, as Discovery News reported.