Contextual Applications of Differentiation · Superchallenge problem

A $10$-m-long trough has an isosceles-triangle cross-section that is $1$ m wide at the top and $0.5$ m deep (apex at the bottom). Water fills it at $0.2$ m$^3$/min. How fast is the water level rising when the water is $0.3$ m deep? Round to 3 decimal places (an exact answer is also accepted).