Shoreline engineering in the form of seawalls, rip-rap, or other solid structures is sometimes used to reduce wave erosion at the toe of a bluff. In some settings, engineering can increase the rate of beach or tidal flat erosion, undermining engineering and weakening the base of the bluff. When coastal engineering ends along a shoreline, “end effect” erosion can cause worse erosion on adjacent properties. Engineering alone cannot prevent some large landslides. In general, human activities that increase the amount or rate of natural processes may, in various ways, contribute to landslide risk.

Eroding bluffs sometimes can be stabilized solely at the base or along the entire bluff surface using a single technique or combination of tree rafts, wattles, geotextile fabrics, rip-rap, or gabion structures. The costs associated with bluff stabilization can be quite high, depending on the size and project design specifications. Permitting may be required for not only the actual activity, but also for staging or seasonal use of equipment, especially if it occurs from the seaward side of the project and is within the “coastal wetland” or below highest annual tide. The guide to Maine Erosion and Sediment Control Best Management Practices, contains stabilization techniques applicable to coastal bluff and landslide sites, including:

• land grading and slope protection
• use of geotextile fabric
• stabilizing slopes with rip-rap
• stabilizing slopes with gabions (rock-filled wire baskets)
• stabilizing streambanks

Be neighborly. Think about potential impacts on your neighbor’s property that may result from an activity on your property. At the same time, it may make sense to work with adjacent property owners if a common goal is found or regional approach is being adopted to deal with certain hazards.

Additional resources regarding slope stabilization are provided by the US Army Corps of Engineers Coastal and Hydraulics Laboratory.