CORPS OF ENGINEERS' VIEWS OF ENVIRONMENTAL IMPACTS OF BEACH NOURISMENT

All construction projects have some environmental impact and beach nourishment is no exception. Impacts can be associated with both borrow and nourishment sites. The borrow sites are generally upland sites, existing navigation channels requiring periodic maintenance, or sites designated solely as borrow sites for the beach nourishment project. Obviously, upland borrow sites have the least adverse impact on the aquatic environment. Periodically borrowing material from existing navigation channels has minor environmental impacts since the project is already dredged for navigation, and the sediment accumulating in the channel bottom is usually the same as that being removed. Borrow sites designated solely for nourishment can experience the greatest impact if the borrow activity affects hard bottom communities, or there is a change in sediment composition. Otherwise, evidence indicates impacts are of short duration. Impacts to the nourished areas are also generally of short duration if the material from the borrow source is compatible with the existing beach. Some management actions, such as tilling, may be required to make the beach more acceptable for nesting sea turtles. Impacts of beach nourishment can be reduced by limiting activities to the colder months when recruitment of beach fauna is often the lowest; however, limiting nourishment to certain times of the year is not always feasible due to the magnitude of the project and costs associated with mobilization of equipment. Extensive monitoring has been conducted related to impacts of beach nourishment, some monitoring is ongoing, and some additional monitoring is needed.