Backed up drainiage

The storm drain grate next to my patio is again becoming clogged during rains resulting in flooding on the patio. I have removed the rocks and dirt once at the base around the grate to clean this out but it has become a recurring problem. The cause seems to be erosion around the rock drain further up the hill and dirt/debris washed into the rocks, see images attached. I don't think any materials need to be purchased to remedy, but simply remove the rocks, landscape liner, clean out and replace.