$($ii$)$ In the year $2025,$ a weir is constructed $14km$ downstream of the outfall which increases

the depth $(H)$ of the river by $30\%$ and increases the cross sectional area $(A)$ by $30\%.$ The

flow rate upstream of the weir is determined to be the same as the $1980$ flow rate. Evaluate

the initial conditions at the outfall and the re$-$aeration rate coefficient $K_a.$ And determine

whether the point of critical deficit will occur before or after the weir. Assume the river

dimensions approximate a rectangular channel.