Please take the time to review the soil types in 1935. And the island names and waterway names. It will help you to understand the problems encountered by scientists and computer modelers who have been direction-ally challenged in the 21st century planning to revise the Delta.
During the 1930’s the USA was struggling with the Depression and as part of the “New Deal” men were put to work improving the existing levees built by the farmers and their crew the century before. The Federal Project Levees were built, and that included the levees rimming Ryer Island and Grand Island. Sacramento River and Steamboat Slough were dredged, and Wood Island between Rio Vista and Brannan Island was entirely removed.