I read more attachments and posts regarding this then I can remember and have my plan for the spring for my own culvert repair job using the filter method....but one question.

Does the culvert lay inline / parrellell with the filter sand trench, or does it cross the filter trench at 90 degrees. It shows everything in the diagrams except actually laying the culvert in place.

I know this is probably so basic but some pictures look deceiving.