Drainage and Waterway Hydrology Study Guide
Instructions for Preparing Hydrology Study
Applicant must prepare a hydrology study for the drainage and waterway facilities as follows:
- Prepare a drawing showing the area involved. This drawing should include the top of rail elevation, the top of subgrade elevation, the bottom of ditch elevation, the invert elevation of the drainage structure and show the track, subgrade, ditch and any other important information (fences, pipelines, other culverts, etc.).
- Prepare a drawing showing a cross section at the point the water enters the railroad right of way.
- Advise the drainage area, the amount of water, the flow rate, the type of protection provided at the outlet end, where the water will flow, the nearest structure to remove the runoff from the right of way and the capacity of the existing structure.
- Advise the existing and proposed 50- and 100-year water surface elevations at both the point the water enters the right of way and at the existing structure that removes the water from the right of way.
Criteria for Drainage Improvements
The Railroad's hydrology/hydraulic criteria for drainage improvements are as follows:
- Ensure that the water does not contact bridge structures in the 50-year event.
- Ensure that water does not pond over the top of culverts or structures in the 50-year event.
- Ensure that water does not overtop the railroad's subgrade, which is 2' 3" below the base of rail, or damage upstream property in the 100-year event.
- Ensure that any new installations on railroad property comply with local, state, and federal design requirements.