Treatment 5: Interplanted Boulders

This treatment was used primarily in Garden areas where granite boulders already existed along the shoreline. Additional imported boulders were utilized, and the existing boulders were redistributed and reset into existing grades along the same and opposite shores to create an intricate boulder-protected shoreline that includes some smaller stone backfill at the normal waterline. Fifteen-inch to 6-foot-wide boulders provide the appearance of outcroppings transitioning from below the normal waterline to 2 feet above it. This gives an additional visual texture to this narrow water channel in the landscape, while providing effective shoreline stabilization. The areas upslope of the boulders had plantings tolerant of somewhat drier conditions.

This technique modestly improves fish habitat, allows softening of the hard edge to reduce reflection of wave energy (compared to sheet piling), and provides a stable shoreline. The primary disadvantage is that this technique provides less aquatic plant and wildlife habitat than treatments with broader planting shelves.

Cross-section view Boulder installation
Treatment 5: Cross-sectional view Treatment 5: Boulder installation
PHOTO: Before restoration
Treatment 5: After shoreline restoration
Treatment 5: Before shoreline restoration