CIV E 444 - APPLIED HYDRAULICS
FALL 2009
HOMEWORK No. 9


  1. A reservoir is being planned in a stream that has the following average monthly inflows:

    MonthOctoberNovemberDecemberJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptember
    Volume (ac-ft × 10-3)5101220322815128554

    Determine the reservoir storage volume required to guarantee a constant release (draft).

  2. Lake Okeechobee in South Florida is about 37 mi long and is relatively shallow, with an average depth of 7 ft. If the wind were to blow over the lake at a speed of 40 mph, what would be the setup? Give this setup, what freeboard is recommended for flood protection if the embankment face is 3 H : 1 V and is covered with riprap (relatively permeable rubble mounds). Calculate wave runup so that only 2% of the waves will exceed it. Allow 2 ft for post-construction embankment settlement and 1 ft for contingencies.

  3. Calculate the sediment yield for the watershed draining to El Capitan Dam, in San Diego County, with drainage area A = 188 mi2 and mean annual runoff Q = 3.5 in.

  4. Estimate the useful life of El Capitan reservoir, given the following data:   capacity V = 112800 ac-ft, drainage area A = 188 mi2, mean annual runoff Q = 3.5 in, annual estimated sediment yield S = 1350 ton/mi2, specific weight of sediment deposits (sand-silt mixture) W = 85 lb/ft3, and the sediment deposits are medium grained. The dead storage is 20% of the total reservoir volume. Recalculate and report results if the actual measured sediment yield is found to be 30% greater than originally estimated [Hint:   Use ONLINE RESERVOIR LIFE].