I walked along the new causway between Schellville and Wingo while tracks were being laid last year. I noticed that there was only one significant point of drainage under the causway north of the Sonoma Creek. I would think that if the Sonoma Creek were to spill over its north bank/dike into the marshes, the causeway would be under a lot of preasure. If there was flood-level water flowing in the marsh, I don't think that the drainage pipes (not even a culvert) could handle the volume. It makes me a bit nervous.