My wife and I recently purchased 2.5 acres in the foothills of California, and there's a lot of vegetation that needs to be removed. In the front of the property is a creek that runs the width of the property, and it's currently overrun by thick, tall cattails. I've researched up and down as to how to get rid of them in an environmentally safe way, but can't be sure of the best practice(s). The creek isn't incredibly deep, so accessing them with a shovel is feasible, but backbreaking.

Any suggestions or product links would be greatly appreciated. Thanks!