49256 - FLOOD ESTIMATION ASSIGNMENT 2 In the previous assignment, an at-site flood frequency analysis was undertaken for the Powells Creek catchment located at Strathfield in Sydney’s Inner West. For this assignment, you are required to use this flood frequency analysis. Additional information required are • Catchment area - 2.4km2 • Catchment location (centroid) - 33o 52' 40" S, 151o 05' 45" 1. Use the available data to determine the following i. The runoff coefficients for 10, 20, 50, and 100 year frequencies suitable for use in a PRM style regional flood method. ii. The growth curve for these coefficients using the C10 coefficient as a base case. 2. Compare the growth curve determined in Part 1 with the growth curve for urban areas used with the Rational Method given in Chapter 14 of ARR87. 3. Comment on the reliability of these two growth curves and hence the uncertainty in predictions obtained from their use.