From California Department of Fish & Wildlife: With the drought-busting rains and snow received last winter, the wildlife area resembled an inland ocean for the thousands of daily commuters traveling the Interstate-80 Yolo Causeway, which crosses the northern edge of the wildlife area. The floodwaters stretched as far as the eye could see, reaching depths of 20 feet in some places, and submerging almost every natural feature underneath. The consequences were dire for wildlife unable to escape.

https://www.wildlife.ca.gov/Science-Institute/News/PostId/68/wildlife-corridors-at-yolo-bypass-will-help-animals-escape-flooding