In a Severna Park project on the Magothy River, Scapes, Inc., installed a timber retaining wall, embellished with a profusion of panicum, viburnum, hibiscus, aster and perennials to provide year-round interest. Photography: Jeff Crandell.
There are three main methods we use to protect and control erosion and flooding: riprap, bulkheads and retaining walls, and vegetation. Vegetation is the most common. Vegetation absorbs rainwater that can cause surface erosion. Roots—especially the deep roots of trees and shrubs—bind the soil, strengthening and stabilizing sloped areas. Native plants also help the overall coastal ecosystem.
Bulkheads and retaining walls are also effective, preventing runoff by forcing the water to soak into the soil. Retaining walls can be made of wood, segmented wall stone or natural stone. If you have multiple walls, terracing can be created that will allow you to install lawn and/or plantings.
Riprap, which embeds stones into a slope or spreads them loosely on the surface, slows or diverts flowing water at the water’s edge. This is a high-cost alternative and creates an unnatural appearance, making it less popular than the other options. —Jeff Crandell, Scapes, Inc., Lothian, Maryland