49 C.F.R. § 213.319 Drainage.
Title 49 - Transportation
Each drainage or other water carrying facility under or immediately adjacent to the roadbed shall be maintained and kept free of obstruction, to accommodate expected water flow for the area concerned.
Title 49: Transportation
PART 213—TRACK SAFETY STANDARDS
Subpart G—Train Operations at Track Classes 6 and Higher
§ 213.319 Drainage.