When is it acceptable to use earthen material for construction causeways and coffer dams?

Using earthen materials for construction causeways and coffer dams is acceptable when they are armored by non-erodible material because this practice ensures the structural integrity and longevity of the installation. Armoring with non-erodible materials, such as rocks or geotextiles, protects the earthen structure from erosion caused by water flow or heavy rainfall. This is crucial in maintaining the effectiveness of the causeway or coffer dam in managing stormwater and preventing potential flooding or sedimentation in water bodies.

In contrast, using earthen materials without proper armoring can result in significant erosion, especially when water flows over or through the structure, ultimately leading to failure. Therefore, the requirement for armoring is an essential aspect of effective stormwater management practices. This option aligns with best practices in construction, ensuring that temporary structures can withstand the environmental conditions and fulfill their intended purpose effectively.