Building a seawall is a tricky proposition: you want to keep erosion to a minimum, but you don't want to alter the natural environment too much. How do you plan a shoreline that is best for the overall health of the lake environment? 
Here are a few tips for seawall planning: -A more natural seawall of nestled stones of various sizes, such as Rip Rap, is the best way to protect the habitat of shallow-dwelling lake critters, allowing organisms to move in and out of the water as well as colonization by some natural insect and plant species.
-A gradual rocky gradient also ensures that the shoreline absorbs waves; straight vertical walls send waves back in the opposite direction, giving the lake that washing-machine feel you might recognize from holiday weekends. -Instead of introducing concrete or other unnatural materials to the lakeside, think about planting local riparian vegetation, which will hold the soil in place without altering the shoreline. (You can mix vegetation and rocks, too.)
-If you still want a dock, think about building a wooden one over the natural shoreline, supported by a few pilings off the shore. Doing so allows waves to be absorbed underneath the dock while giving you a place to park your boat or jump into the water.
