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<br />WO
<br />WI
<br />W2
<br />W3
<br />W4
<br />W5
<br />W6
<br />W7
<br />W8
<br />W9
<br />
<br />MEEKER GAGE (2.5 MI VIS OF MEEKER)' 1024 mi'
<br />
<br />a
<br />
<br />Meeker. Ice jams can occur at bridge crossings and channel constrictions where flooding can
<br />occur from otherwise non-damaging flows in areas ordinarily only affected by much higher flows.
<br />The jams can reduce channel capacity so much that the small flows cause significant flooding.
<br />Additionally, ice jams can release stored water without warning when the jams fail, causing a
<br />destructive wave to move downstream. Rain on snowmelt floods result from the augmentation
<br />of already high snowmelt flow volumes by the added runoff of rainfall. These types of floods
<br />can be characterized by the already moderate peak flows of snowmelt floods followed abruptly
<br />by a short duration high flow. The construction of a dam approximately 7 miles upstream of
<br />Rangely, although not constructed for flood control purposes, is expected to reduce the flooding
<br />caused by ice jams in Rangely by altering the temperature patterns in the river.
<br />
<br />TABLE 2
<br />
<br />
<br />....,-.:,-..::-'...._'......-,:,'. '--'...
<br />-.....-,..,-...--- ."...... ..
<br />.'_...._. ..'_.._..... - n'
<br />...~-gi::lJ.,~(9.........
<br />POINT? .
<br />...... .,n
<br />... n.
<br />
<br />.:'..' ....-'-.--;,-......-:-....,.-'......,-.,...-.'-.,..........,:.'
<br />n... _" _,..n.,_,'_'---,.,_,." _
<br />.'-'.- .-.-'-',..,-....--..-..-...--,.-,-..,.--..-'.-.-:.......
<br />'iitll~AmAG.EL?
<br />..-,-.--'_.._'._',-...._---_....,-..-,-.--.........'.-.,..
<br />............._ _,..... __ n',., ,
<br />, . ,,-- --......._-.- --....-....-
<br />'.:.'.A...JffiA......(Q$... ;)...'.':.'.
<br />, .,......_ ,.n...
<br />., . ".
<br />
<br />WIO
<br />
<br />ABOVE PICEANCE CR 1204 mi'
<br />BELOW PICEANCE CR 1856 mi'
<br />ABOVE YELLOW CR 2018mi'
<br />BELOW YELLOW CR 2280 mi'
<br />BELOW WOLF CR 2460 mi'
<br />BELOW BOISE CR (GAGE SITE) 2530 mi'
<br />BELOW SPRING CR 2620 mi'
<br />ABOVE DOUGLAS CR 2880 mi'
<br />BELOW RANGELY AT DIS LIMIT OF 3300 mi'
<br />FEMA STUDY
<br />STATELINE 3552 mi,
<br />
<br />b
<br />b
<br />b
<br />b
<br />
<br />a
<br />
<br />a
<br />
<br />b
<br />
<br />a
<br />
<br />a
<br />
<br />b
<br />
<br />Sources of Drainage Areas
<br />a Determined from published information and USGS gage values
<br />b Determined from upstream USGS gage information combined with planitnetering
<br />.. Not in study reach
<br />
<br />Figure 4 shows the study reach and each of the hydrologic analysis points listed in Table 2.
<br />
<br />2.5 Flood Characteristics
<br />
<br />Major flooding in the White River basin has been primarily the result of rapid snowmelt
<br />beginning as early as late April. Snowmelt flooding can continue into early July. Flooding can
<br />also occur from rainfall on snowmelt and from ice jams in late winter or early spring. Due to
<br />the small areal extent and limited duration of thunderstorms, they do not typically constitute a
<br />major flood threat on streams as large as the White River. They do, however pose a problem for
<br />some of the smaller tributaries in the White River basin.
<br />
<br />Snowmelt flooding is characterized by moderate peak flows, large volume of runoff, long
<br />duration, and diurnal fluctuation of flow. Flooding from general rainfall alone, though
<br />uncommon on the White River, is characterized by high peak flows and moderate duration of
<br />floodfIows. Historically, ice jams, rain on snow, and local thunderstorms have caused the greatest
<br />flooding around Rangely. Snowmelt floods of 1983 and 1984 produced IOO-year flows at
<br />
<br />7
<br />
<br />8
<br />
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