Culvert replacement
Damaged culverts are one of the four most common impacts to agricultural drainage. Culverts that are undersized or damaged can impact the drainage of agricultural fields. The Agricultural Drainage Assistance Program (ADAP) has developed a manual of best management practices (12.2 MB) (BMPs) for addressing these impacts.
New culverts need to be the right size to move water to the right place. The Washington Department of Fish and Wildlife (WDFW) has standards for sizing culverts. This WDFW publication lists these standards: Design of Road Culverts for Fish Passage.