just tell her you're following Corps of Engineers guidelines!!
http://www.fwspubs.org/doi/suppl/10.3996/022015-JFWM-012/suppl_file/022015-jfwm-012.s7.pdf?code=ufws-site
http://www.fwspubs.org/doi/suppl/10.3996/022015-JFWM-012/suppl_file/022015-jfwm-012.s7.pdf?code=ufws-site