Hi all. My run is being built next to an above ground storm sewer. My property slopes toward this drainage area so I am going to build a retaining wall on the low end of the run to level the ground area that the birds will be in. The retaining wall will be approximately 1.5 feet tall built with treated 6 x 6 timbers. On the inside of the run I am going to place landscape fabric down, covered by about six inches of pea gravel then I will top off the area with 6 inches of river sand. I have read many post citing the use of hardware cloth and the benefits of burying it 6 inches underground however I am considering laying it flat under the gravel and sand on the interior perimeter of the run. This would save me a lot of effort and I just cant imagine an animal being able to dig under a retaining wall then up through the other side and somehow coming up through 3 foot wide hardware cloth that is laid flat on the ground and is covered with over a foot of rocks and sand. Predators in my area include raccoon, dogs, coyote, and fox. With my retaining wall being 1.5 feet above ground level I thought I would put 6 inches of hardware cloth above the retaining wall for added security. So my question are: 1. Am I missing some obvious reason why this will not be a decent idea? 2. Any idea how long galvanized wire will last if buried? 3. Any suggests on how to improve this design? Thanks!