Is there a water inlet just north/top (end of pic). I am concerned that silt does not wash in on the beach. I would check other fill options. Sand on top of gravel works well and cuts the rock amount down a bunch. Pea gravel costs too much and larger size hurts the feet. Big gravel covered with sand may be an option. White sand (masonry) not red road sand. Rock gets slippery over time with growth and or silt , sand does not. Sand can be raked to clean it up rock no so easily.