I have a comment directly in response to that.
Certainly, permanent grassland cover is a very important mechanism to reduce flooding. There are programs, and in fact Ducks Unlimited has a struggling program on carbon investments. Grasslands are extremely effective at storing carbon for almost permanent storage.
I own a farm in Iowa, and there are places on my farm where the black topsoil is almost as deep as I am tall. That's all been accumulated over the last 9,000 years. Tons and tons of carbon is in the soil in native grasslands.
By converting marginal cropland into permanent grassland cover, we achieve the flooding protection but we also squirrel away as much as 30 metric tons of carbon per hectare per year into these soils. Permanent grassland cover is an extremely important change in management for some of those watersheds that are flooded so heavily, and by focusing on a carbon tax, and taxing industry that is producing excess emissions, we can achieve both ends.