Cross veins are meant to channel flow usually toward the center of the stream, these kind of structures are usually ephemeral. They get blown out as soon as the next big flood.
What does work is planting trees, but even that has limitations. Some get eaten, some get washed away. But many will root and grow large shading the stream and when they fall they create more permanent habitat.
Notice I said more permanent, I use that term because streams are dynamic environments, and I laugh when people say the are doing a restoration when they mean something else. Well not really, but even large tress have a lifetime, they ofter have out lived us, and of the hundreds of trees and shrubs I planted along our watershed, I certainly hope even a few will out live me. If they do Perkiomen Creek and it's tributaries have a bright future.
