CIV E 444 - APPLIED HYDRAULICS FALL 2009 HOMEWORK No. 1 Determine the 100-yr flood by the Gumbel method for the following flood series (cfs): 1532,3721,1498,2879,1899,3245,3692,6276,1245,2745 A rural basin in the South Coast region of California has a drainage area A = 185 sq mi, and mean annual precipitation P = 16 in. What is the 100-yr flood? [Hint: Use USGS State equations]. What is the runoff coefficient in a basin located near the middle of the climatic spectrum, with annual precipitation P = 32 in, ecosystem evapotranspiration ET = 22 in, and baseflow U = 3 in? What is the 10-yr peak flow for an urban basin with drainage area A = 325 ac and rainfall intensity I = 2 in/hr. Assume C = 0.7.