Beach nourishment is a practice in which sediment is brought onto a beach to replace sediment which has been lost through erosion. There are advantages and disadvantages to beach nourishment, and in some regions, it is a controversial practice. Because humans like to settle near beaches and enjoy using beaches as recreation areas, this practice is quite common around the world, despite some of the environmental problems associated with it. Rising global sea levels have also contributed to the rise of beach nourishment in many countries.
Beaches lose material to erosion all the time. The actions of waves, storms, and shifting landmasses all contribute, and, in a healthy beach, new sediment is redeposited as old material is worn away, in a prolonged cycle which keeps the beach more or less intact. Some human activities can increase the rate of erosion, however, allowing the beach to be eaten away faster than it can be replenished. The use of sea walls, artificial sandbars, and other retaining walls can all contribute to erosion, as can filling wetlands and other border areas near a beach with backfill, housing developments, and so forth.
If a beach becomes eroded enough, it may vanish altogether, and the ocean will start creeping inland. Beach nourishment aims to stop this process, at least temporarily, by importing new sediment for the beach. The sediment may be dredged from neighboring waters or trucked in from another location before being spread across the beach, with biologists being careful to use sediment similar to that which exists on the beach naturally.
The immediate advantage of beach nourishment, also known as beach recharging or beach replenishment, is that the beach stops shrinking. However, the new sediment tends to erode again, often more quickly than the original beach, necessitating a repeat of the procedure. Beach nourishment is also very expensive, depending on the cost of the sediment, and practices like dredging can harm neighboring marine life. It may also encourage people to settle near the beach, increasing the rate of erosion even further by promoting human activities.
Because beach erosion is often heavily influenced by human activity, there are some ethical issues to consider when evaluating a beach nourishment plan. If the beach is eroding naturally, some people advocate for leaving the beach alone, and allowing the landscape to adjust itself naturally. If the erosion has been sped by human activities and it threatens low-lying land or structures which neighbor the beach, however, people may push for beach nourishment, treating it as environmental restoration rather than the creation of an artificial beach.