Landscape Issues With Wave Erosion

Movement

• The sandy area between the water and the land is formed by the constant movement of water. Waves typically move material back and forth in the “littoral” zone -- the area between the shore and a boundary in the water, often marked by sand bars and drop-offs, where the material is dropped. In a perfect shoreline, this material is picked up by incoming waves and deposited back on the shoreline. However, variables such as tides, storms and the slope of the land above and below the waterline alter the amount of material carried out and brought back in to the shore. When landowners change vegetation or build structures, they disturb the equilibrium further. The challenge for landscapers is to create a landscape without upsetting that equilibrium and stabilizing the shoreline against further movement outward.

Soil

• Shoreline soil is washed clean of organic matter until it is worn down to its core of fractured rock -- sand. In order to plant along shorelines, organic matter must provide nutrition for grasses and other salt- and water-tolerant plants. These plants stabilize dunes -- the barrier that protects more fertile soil and landscape elements behind them. Dune subsoil may also be sandy but it more often resembles soil in the surrounding area; it may be predominantly clay or loam as well as sand. Soil amendments, topsoil and additional watering give newly planted materials a boost to start growing and conditioning soil themselves.

Maintenance

• Some waterside dwellers have to resign themselves to starting their landscapes over periodically. Hatteras dwellers know that a big hurricane can change channels and shorelines as Irene did in 2011 and Great Lakes dwellers face ferocious storms like the one that sank the storied Edmund Fitzgerald in 1975. Landscape materials must stand up to less violent weather, and homeowners must be able to complete maintenance such as mowing or thinning during seasons following storm season rather than just prior to it. Native plants are already adapted to the climate and weather patterns of an area and will survive local extremes easily. Nonnative varieties may become invasive or fall prey to local pests.

Best Management Practices

• State and local natural resource and conservation agencies may place demands on homeowners that, although they seem arbitrary, are designed to stabilize and maintain shorelines. Grading, runoff control, toe protection, foundation requirements and limitation of building all create issues for shoreline landscapers. Most agencies provide outreach to property owners to interpret best shoreline management practices. Multistate organizations such as the Chesapeake Bay Program, Lower Columbia River Estuary Partnership and Rock River Coalition provide best practices support for property owners with emphasis on consequences for entire watersheds.