$[50$ points$]$ At a given location, under normal conditions a river flows with a Manning coefficient of $0\mathrm{.}030,$ and a cross section as indicated in Figure $($a$)$ below; during flood conditions, the river will have Manning coefficient of $0\mathrm{.}040$ and a cross section as shown in Figure $($b$)$ figure below. Both conditions have a channel bottom slope of $0\mathrm{.}01.$ Calculate the flowrate during flood conditions and the flowrate during normal conditions.