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Table 34 Minimum Monthly Hydrographs, Yampa River at Deerlodge Park ------------------------------------------------------------------ Month Historic 65% Peaks 74% Peaks, 72% Peaks, Depleted, Record Retained Redistributed and Redistributed --------- ------ Oct ---------- 449 ------------- 449 --------------- 449 ------------- 449 Nov 452 452 452 452 Dec 381 381 1101 925 Jan 358 358 1079 902 Feb 461 461 1182 1005 Mar 986 986 1707 1530 Apr 3592 2335 2658 2586 May 8683 5644 6425 6251 Jun 7714 5014 5709 5554 Jul 1864 1864 2605 2426 Aug 469 469 1211 1032 Sep 270 270 •1012 833 -- ------ mean ---------- 2143 ------------- 1560 --------------- 2136 ------------ 1999 --------- cfs mean 1, 551,460 1,129,388 1,546,393 1,447,209 acre-feet mean 2, 602,600 1,674,190 2,307,950 2,153,800 total tons The above hydrographs demonstrate how an approximate equilibrium in sediment transport through the reach may be obtained, yet at different annual yields of water and sediment. Even though a quasi-equilibrium condition is maintained in each hydrograph, it is not the same equilibrium as the historical equilibrium and alluvial areas will adjust from current conditions to the new equilibrium. To aid in putting the different hydrographs in perspective, the maximum end-of- month total sediment balance figure was translated into cubic feet of bedload size material per foot of channel length. This is for the 28.6 mile reach between Deerlodge Park and Mathers Hole; assuming the majority of material is sand sized (97 lbs/ft3) and 7% of the total load is bedload, as reported by Elliott (1984). This approximation would 'smooth out' all the localized alluvial areas over the whole channel length, and is is for illustration purposes only. Aggradation or degradation that actually occurs would be in localized areas and not over the entire channel. The historic and baseline conditions were 1.4 and 1.6 ft3/ft of channel length, respectively. The Juniper project was 37.2 ft3/ft, while the minimum hydrographs were 10.4, 9.8, and 6.8 ft3/ft of channel length for the 73%, 72%, and 65% scenarios. The above table also shows the reduction in tons delivered to the Green River as a result of maintaining quasi-equilibrium conditions different from the historical condition. This information can be used to evaluate channel changes in the Yampa River to Duchesne River reach.