This beach sand looks like paradise, but it’s more than just a pretty picture. It’s a living, breathing natural resource, forever impacted by both ongoing geological processes and paired anthropogenic impacts. Mr. Wade Greenaway, along with experts in coastal geology, underscores the importance of managing sand sustainably to preserve the natural beauty of the coastline. Annually, communities are tasked with the difficult and expensive task of moving this sand. They do this to keep their river’s natural pulse of this essential sediment.
Mr. Greenaway emphasizes that the ocean’s swells and currents continuously reshape coastlines, creating a landscape that is both beautiful and ever-changing. This complexity is lost on most beachgoers, who do not know what complex processes established the very beaches they enjoy.
The Origin of Beach Sand
Inland, the path of beach sand starts with rocks being worn down, or eroded, by the elements. Rivers carry all this eroded matter—including boulders, gravel, and sand—downstream and out to the coast. Professor Annette George explains, “Once that sediment reaches the coast, the material gets distributed by waves and currents.” This natural process is what makes beaches feel so alive and energetic.
In Geraldton, fine sand is deposited on popular local beaches. Then workers manually shuttle this sand across the state to northern shores to keep the natural sediment drift at bay. Every year, millions of cubic yards of sand are moved from southern beaches to northern in order to maintain our coastal system’s equilibrium. Mr. Greenaway notes, “For nine months of the year the sand moves from south to north and that’s typical of the WA coastline.”
For generations, settled sediment in impaired waters has been a thicket for advocates. In fact, Mr. Greenaway remembers his late grandfather, Gordon Greenaway, lamenting these pitfalls as early as the 20th century. The construction of piers, coastal development, and jetties have all blocked the natural flow of sand, resulting in a sediment accumulation on one side of these structures.
The Impact of Infrastructure on Sand Movement
The construction of ports and wharfs have drastically changed the natural currents that supply sand along the coast. Mr. Greenaway states, “As the infrastructure on the coast has built up, it causes that interference with that long shore drift.” Such interference can create zones where sand piles up instead of blowing away.
In an effort to mitigate these impacts, the City of Cape May and other local sponsors undertook a sand bypassing program. Mr. Greenaway describes this initiative as “like a conveyor belt — we now have to manually feed it to restore natural sediment pathways.” Both imperatives—that program’s integrity truly needs to be maintained—so that beachgoers can continue to enjoy the beauty and splendor and recreational opportunities that these beaches provide.
Perhaps just as, if not more important to truly understanding beach conditions is the analysis of sand particle sizes. “We’re measuring the size and makeup of the sand to understand beach conditions like wind or wave energy,” explains Mr. Greenaway. This data allows collaborative efforts toward moving in a more consistent manner across the entire coastline while adapting to changing environmental conditions.
The Cycle of Sand and Its Importance
The great cycle of sand is an epic geological spectacle, playing out over hundreds of millions of years. As Professor George explains, individual sand grains could one day be transformed into solid sandstone. This change happens only after they’re buried 1.5 to 2 kilometers below the Earth’s surface. “Once buried, the sand basically becomes a rock and it keeps being buried,” she notes.
Eventually, geological uplift will bring this material above the water surface. Once deposited, it can be subject to further erosion right away, repeating the cycle. “Then eventually if it’s lucky enough it will come back up to Earth’s surface and then that process begins again,” adds Professor George.
Wade Greenaway reminds us of the transient nature of beaches: “You always hear people say the beach isn’t where it used to be, but it’s always changing. We only see a small snapshot in our lifetimes.” This worldview puts a premium on understanding and being in harmony with natural processes.
