A rectangular reservoir with vertical walls has a plan area of 60000m2. Discharge from the reservoir take place over a rectangular weir. The flow characteristics of the weir is Q = 0.678 H3/2 cumecs where H is the depth of water above the weir crest. The sill of the weir is 3.4m above the bottom of the reservoir.Starting with a depth of water of 4m in the reservoir and no inflow, what will be the depth of water after one hour?