A 400ha catchment area situated near Newcastle in Natal (inland region) has an average annual rainfall of 850 mm. The elevation of the discharge point is 1 323m and the elevation of the point at the head of the natural channel watercourse, which has a length of 2.8 km and a fairly uniform slope is 1 379 m. The catchment 20% cultivated land and 50% grassland. The soil permeability over the catchment area can be considered to be 25% semi-permeable, 35% permeable and 40% very permeable. The average slope of the hillsides (So) in the catchment was calculated to be 4.2% over 65% of the catchment and 3.1% over the remainder. covered by 30% dense timber plantations, Use the Rational Method calculate the peak discharges for 10-year, 25-year and 50-year return period (recurrence interval) storms. Plot a graph of your results. (Refer to Annexure A)