BEsT MANAGEMENT PRACTICEs HANDbooK - Tahoe BMP

Case 1: the toe of the protective measure lies above the maximum still waterlevel. Only broken waves reach the structure. The wave height is calculatedbased on a broken wave, as described in Section 8.16.1.5.Case 2: The waves break offshore of the toe of the protective structure at themaximum still water level. The wave height is calculated based on a brokenwave, as described in Section 8.16.1.5Case 3: The waves are not broken at the toe of the protective measure at themaximum still water level. However, the waves do break at the toe of theprotective structure for some water level. That is, the water depth db isobserved at the toe for some water level between the minimum still water level,6,223.0 feet (1896.8 meters), and the maximum still water level, 6,229.1 feet(1898.6 meters). In this case, design the protective measure to account for wavebreaking at the toe (Section 8.16.1.6) and unbroken waves at the maximum stillwater level (Section 8.16.1.7).Case 4: The waves do not break at the toe of the protective measure at anywater level. In this case, use only unbroken waves (Section 8.16.1.7). In thiscase, the design must be performed by engineers that regularly perform suchservice.8.16.1.5 HEIGHT OF BROKEN WAVE – BROKEN OFFSHORE OF THE TOECalculate the wave setup at the toe of the protective measure (CEM II-4-23),where dt is the still water depth at the toe:d b d t81 32b(Equation 16.16)The wave setup is an increase in water depth that results from wave action(Refer to Figure 8-v). The engineer may include the effect of wave setdown(CEM II-4-21) if desired.CHAPTER 8: Shorezone Protective Structures and BMPsTRPA BMP HandbookPage 8-108 2012