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<br />3.2 Hydraulic Analyses
<br />
<br />Analyses of the hydraulic characteristics of streams in
<br />the community are carried out to provide estimates of the
<br />elevations of floods of the selected recurrence intervals
<br />along each stream studied in detail.
<br />
<br />Hydraulic information for Boulder Creek was obtained from
<br />a recently completed restudy of the creek done by the
<br />u.s. Army Corps of Engineers.
<br />
<br />Hydraulic information for South Boulder Creek was
<br />obtained from the Boulder County Flood Insurance Study
<br />(Reference 3).
<br />
<br />Cross sections were field surveyed and water surface
<br />profiles developed using the U. S. Army Corps of Engin-
<br />eers backwater program. Profiles were determined for
<br />the 10-, 50-, and 100-year floods. Elevations of the
<br />100-year flood at selected cross sections for Boulder
<br />Creek and South Boulder Creek are given in the following
<br />table:
<br />
<br />Cross Section
<br />
<br />.
<br />
<br />Boulder Creek
<br />A
<br />B
<br />C
<br />D
<br />E
<br />F
<br />G
<br />H
<br />I
<br />J
<br />K
<br />L
<br />M
<br />N
<br />o
<br />P
<br />Q
<br />R
<br />S
<br />T
<br />U
<br />V
<br />W
<br />X
<br />
<br />1
<br />Stream Distance in Feet
<br />
<br />. 1
<br />Dlstance
<br />
<br />Elevation of
<br />100-Year Flood
<br />(Feet NGVD)
<br />
<br />109,650
<br />110,600
<br />112,000
<br />113,700
<br />113,800
<br />114,640
<br />115,550
<br />116,350
<br />117,050
<br />117,600
<br />118,600
<br />120,180
<br />120,800
<br />121,700
<br />122,130
<br />123,010
<br />123,920
<br />125,075
<br />l25,675
<br />126,450
<br />127,425
<br />127,800
<br />129,000
<br />130,290
<br />
<br />Above Mouth
<br />
<br />5,198.3
<br />5,204.1
<br />5,213.5
<br />5,223.1
<br />5,226.5
<br />5,230.2
<br />5,235.4
<br />5,242.0
<br />5,245.5
<br />5,250.4
<br />5,256.5
<br />5,272.3
<br />5,274.9
<br />5,284.7
<br />5,289.4
<br />5,298.4
<br />5,306.0
<br />5,316.0
<br />5,325.3
<br />5,332.4
<br />5,341.1
<br />5,348.0
<br />5,360.1
<br />5,373.6
<br />
<br />5
<br />
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