I don’t know if this is the best way to manage, but it is what I have been doing on the Cheyenne Bottoms Preserve here in Central Kansas. We have been aerial spraying cattails for the past couple of years in order to recover our open water and shallow water habitat. We use the lowest amount of chemical required to kill cattail so as not to put excess chemical into the system. Chemical spraying is not a method that The Nature Conservancy implements without weighing all the options, but the landscape has changed dramatically, and we will need to make large scale and sometimes expensive decisions if we hope to maintain any resemblance of a true prairie marsh. Glyphosate labeled for over the water treatment binds tightly to soil. It can persist in soil for up to 6 months depending on the climate and the type of soil it is in. Glyphosate is broken down by bacteria in the soil. Glyphosate is not likely to get into groundwater because it binds tightly to soil. In one study, half the glyphosate in dead leaves broke down in 8 or 9 days. Pure glyphosate is low in toxicity to fish and wildlife. The amount used to control cattails in not strong enough to kill phragmites, so we retreat those stands the following year and this seems to be successful. Shorebird and waterfowl numbers have increased significantly as we have restored more open water and shallow water habitat.