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Mean-Annual Total-S2di~e0t Leads The mean-annual total-sediment lDad for each of the selected ~aging stations in the Yampa River basin \':as cor~put'2d b':' combining the daily total- sedir-ient load versus daily r,lean-discharge relations v/ith the respective flo\-J- duration curves to give sediment-load-duration curves. The latter curves \"ere integrated and the sums \'.ere ITultip:i':d by 365 days per year. The average-annual total-sediment loads and water ~isc~arge5 for the 17 gaging stations are summariz'2d in table 2. Sedimi:"!t loaes and v:ater dis,charces for en additional station, the Yi3mpa River ,a,t Jeer;ocge P<lrk (fig?-':'.:, 1), \'Iere computed b"y summ'1ng the sedif;1ent end '-\.>131:'er discharges for the Li tt_le Snake River near li Iy al,d tne Y,;impa River near t"aybe11" and adj-usting for the intervening ungdged drainage area.,_Th<:.-estirated'-:;:ean-annual total-sediment load and v/ater discharge of.--~he Ya~pe River 3t DeerloGge Park are 2.0 r:-:i 11 ion ,-ons (1.8 mi l++-mr;-t) and 2,125 ft3/s (60.2 r,,'/s), respectively. Accuracy of ~omputational ~ethod Annual sediment loads com2uted by the flo~-duration, sediment-transport- curve method are less accurate than the values which would be obtained from continuous or dai ly measurements. Ccmmo~ly, there is a considerable scatter of observations about the mean relation betv:een sediment load and I'later dischar"ge. Furthermore, there are occasio:lally seasonal shifts in the sediment-load, water-discha~ge relation. Consequently, it is unlikely that a single' sediment-transport curve vii] 1 accurately represent the actual sediment-load curves during an extended period of time. A comparison by ~1i ller (1951) indic2tec .'in error of only 4 percent during a 19-year period between the measured average annual sediment loads and the sediment loads computated by the fl~~-dur2tion, sediment-transport- curve method. Larger errors of 10 to 2C percent were computed by Colby (1956) and Bennett and Sabol (1973). Measure~en:s and computations by Wal- ling (1977) indicate that the flO\-;-duration, seckent-transport-curve method ray underestimate the annual sediment load by 2S much as 30 p~rcent in small drainage basins where sediment loads consist predorinantly of s1 It and c1ay. Mean-annual total-sediment loads cor~L:ed by the flow-duration, sediment-transport-curve method co~pare v~r; ~el1 \~ilh those computed fro~ ~easured dai ly sediment loads for the Ya~~a ~iver near Maybel! and the Little Snake River near Lily. For the YamDa Ri';er r2ar r"ay~ell, the fIO'.'l-duratio~. sediment-transport curve estinlate '.':.3511 p'.=:rCcCn: greater than the 7-ye2r average load based on measured dai ly sedi~ent loads. The flow-duration, sediment-transport-curve estimate of the average annual sediment load of the Little Snake River near Li ly was only 4 oerCElt greater than the average annudl loads based on nearly 6 years of measured daily sediment loads. These comparisons indicate a somewhat greater acc~racy for th~ flow-duration, sediment-transport-curve method than previc~s s:u~ies. In general, h0weve~, the uncertainties in the co:;:puted annual secir,ent loads for streG~1s In the Yampa River basin are probably larger; perhaps 10 to 20 percent, as found by Colby (1956) and Bennett and Sabol (1973)" 11