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Show 52 Utah Academy of Sciences, Arts and Letters Table 1. Maximum Drainage Basins. Drainage Basin Discharges .Irom Area Flood Calculated (acres) Producrns Dlscharqes' (cu. ft. sec.) (cu. ft. sec. sq. mi.) I?errys Hollow 388 2,400 3,950 W. Fk.· Valley View 128 880 4·,400 E. Fk. Vally View 47 286 3,.880 Mauseleum Gulch 68 420 3,950 'Discharge calculations are based on the general formula Q=av in which a= cross section channel area and v=velocity. Velocity was derived by the Manning formula: v=1.486rYJs.Vz in which r=hydraulic radius of channel. s=schannel slope and n=a coefficient of roughness. The value of these fac tors and of a for the channels in each subbasin are as follows: a r Perrys Hollow W. Fk. Valley View E. Fk. Valley View 100 '.12 40 2.86 2.35 .16 .047 26 1.53 .09 .054 Mausoleum Gulch 35 1.75 .07 .047 n .043 .1. A comparatively high discharge is reported to have' occured several years ago from a denuded watershed above the Garfield Smelter near Black Rock at. the north end of the Oquirrh Moun tains. Several equally high discharges have occurred elsewhere in the United States," There are no records of previous summmer floods. from the drainage basins above the City Cemetery. _ .... The flood waters carrying large quantities of rock, gravel, and debris 'debouched onto the Wasatch Boulevard. A 3 foot high· masonry wall along the south side of the boulevard temporarily restrained the flood waters and caused considerable deposition of debris. This wall failed at a point opposite the mouth of Per rys Hollow and allowed the flood to cascade down a 40 foot fill onto the northeast corner of the City Cemetery. Run off from Valley View Canyon crossed the boulevard at about the same time [and passed into the Lindsey Gardens and down M Street. .... . .... .... .... I Perrys Hollow run off augmented by some from the smaller gulch, ripped out part of the boulevard then crossed the City Cemetery diagonally toward the southwest corner at 4th Avenue and N Street. Within the cemetery, the flood waters gouged out .... tombstones, trees, shrubs, lawn, gutters, and roads. It wrecked part .of the cemetery greenhouse and tore- out several sections .of iron and concrete fence along the south boundary qraves, of the cemetery. |
