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• ?;a::imum gaged floor ra.es for the water nears 19?S, 13?7 and 1473 toere _,IEO, <br />i00 a.nd 1:230 cfa, res necci ve_'y. and occ:lrrEd in ;day of each near. Fti nirrrum <br />gagEd ilc:os mere 29 cfs `,~ Aug;rst c° 1570', 5.9 ors =.: ~'u1.~: or 1977, and 29 <br />cfs in Octo3er of 1973. <br />Ficure ? gives the discharge and suspended sediment of the :~%iZlia.~s Fork liver <br />nEar its meut.h for c~rat~ar tear _'?79. Sediment concentrations during tte snow- <br />melt season were mcch higr:er in the ['illiams r'ork the: the ~_Yamoa for smaller <br />d_'scl:arges. BasEfiow concentratiors of suspended sc-:iiment :Dare similar Ter <br />both rivers . <br />Tile Trapper Fins drainages ~_~ aL ephemeral with runoff oroduced mainly from <br />snowmelt. .Some sur,ner thunde-storms produce runof_° for short Periods. <br />The remainder of this section contains informa;:ion on the enhe.merai drainages <br />o the m:ne area. Annual water wield from t.hsse watersheds ranges from [ acre- <br />feet/year to 225 acre-feet/wear based uper; a.-. esuimatE of approximately one <br />-rcir of runoff per unit Brea cf surface. <br />kcroff information from Johnr;on Gulch p-ovides ti;c most reliable site-specific <br />ir:formation cn t:e t.ir~ing o` yields from the mine-p1ar, area. F'_OUre 10 stows <br />cumulative dischcrgES trop the John Gulch :watershed from ;d.~rch to Dece.mher, <br />137.`. ft should ba noted that stati cn S-a is bel o:v the confl uerce e` Jcirrscn <br />and ?veatt Gulches. The majo-i.tu ci runoff ocgurred in the spring with over <br />• half the meld occurring in. _1pri1. This corresponds to the re;ional distri- <br />i:uti ons c_F flows :~~rh pack -'cn,s cccucrir.g _ tie sprz ng. <br />.Surface h'at_r Qualitu <br />Ir. addition CO yield, rater guality also varies seasonally. '_''~t3Z a:rsperded <br />sediment loads are at a maximum during DEak flows d550C_dtt?d Wlth spr=..^.Q run- <br />off. Steele e*_ al., (1975) reports that up to 40 rer cent of the annual sedi- <br />ment load of the 'tanpa River at the ;daybell ststicn is discharged during the <br />period of srow.reit runoff. Figtres v, 7, and 9 present the graphs cf suspended <br />sediment and discharge for the h'auden and Cram sites or. tie Yampa and the mcatc <br />of the Williams 'cr}: _ivars *espectivelu. Dissoved solids goads show the <br />opposite relationship to sus?ended solids !~Taries 2 and 3). Xigh oualii:y <br />srowmelt runoff ccr.tains relatively 1cti' levels of total dissolved solids (TD,S;. <br />Therefore, concentrations of .DS decrease durine peak flrn: periods. ~n t!:e <br />summer, :dhen grou::d rater discnar~ge makes up a ~.erSer percentage of~the flow <br />ir. ..__ ri•.-ers, TDS values incr•~ase. ^1:e Colorado f^water ^nrservatio:n hoard <br />reports that ir,ter~nittent (ard ephemeral) streams at sower e_'ecat-_ons produce <br />most of the dissolved and sus Derded solids that leave t:'e hasin. <br />^he dominant cations in the Yanpa and Williams Fork .4i.•ers include calcium, <br />sodiam, and macnesium, v;:i?e cio~airara amens arm bicar~»nat~a an; ~u'fate t~~irh. <br />some chlo*.ide present. Surface .•a~.tar in the ephemeral drainages crossing the <br />Tre.oper minesite i.s the were cha:rical tope as ttat in t`e Yampa and [Jil_iacs <br />Fo_:k .._rr rs, ': ut conc_stratiors o` ions are ner.=raliu higher. TDS ~~a _'ue.; are <br />aErerally an order of macri rude hig!:er then these of *_he r~ajcr rivers. 7h'_s <br />• is e::pected from Iomer ai ti tulle intermittent anc' eptemE rai drai naoc-s. <br />