<br />st.-uctu.-ein'lolved.
<br />
<br />A p.-onounced increase in flow velocities usually
<br />
<br />occu.-s downstream from an obstruction, thus increa~ing the flood's
<br />damage pot~~tial. Obstructive new developnent and future land fills
<br />in or near the stre~ms' floodway can be ~ major factor in multiplying
<br />the adverse effects described above.
<br />Estimated future flood crests and pertinent elevations
<br />at bridge crossings and culverts within the study area are listed
<br />
<br />in Table 4. rcr
<br />limited clogging
<br />
<br />purposee ",f this .stool', it ha~ b,,~n assll!'Oed that
<br />can be expected and that all bridge structures and
<br />
<br />culverts would remain intact.
<br />
<br />Significant changes in this premise,
<br />
<br />imposed bY,differing COnditions of a future flood, could alter the
<br />estimated flOod crests and flood limits shown in the table and
<br />related plates.
<br />
<br />TI\.FlI,E3
<br />
<br />rLOOD CAARACTElUSTICS OF SALT CREEK
<br />
<br />Averaged Maximum Conditions
<br />~aqnitudC of Occurence
<br />
<br />Characteristic
<br />
<br />5tand"rd
<br />Project
<br />""'"
<br />15,129
<br />11.0
<br />'.0
<br />n
<br />
<br />Intermediate
<br />Regional
<br />Flood
<br />
<br />9,182
<br />
<br />Peak Discharge (cis)
<br />Height of Rise (feet)
<br />R~_t~ of ~j~.. (1'''''.1" !,"r h'.",rl
<br />Duration of Flooding (hours)
<br />~in Channel Velocity (feet per second)
<br />Overbank Velocity (feet ~er second)
<br />
<br />7.7
<br />
<br />u
<br />u
<br />'"
<br />U
<br />3.8
<br />
<br />'-'
<br />
<br />Future rlo<xJ Heights
<br />Throughout the study reach, average water surface ele-
<br />vations for t~e Standard Project Flood exceed those of the Intermediate
<br />
<br />Regional Flood by 2.5 f..et.
<br />
<br />rigures 2 and 3 show th" height that
<br />
<br />~~ld b" r~ched by future floods on facilities presently cxistinq
<br />
<br />within the flood plain con~idered in the study.
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