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<br />-. <br /> <br />b <br /> <br />e <br /> <br />tit <br /> <br />e <br /> <br />Table 2. Comparison of Aqnatic Macroinvertebrate Results 2in Rock Creek on the Table <br />Rock Ranch 2002 vs. 2004. <br /> <br />Station 2002 BCI seore 2004 BC! score <br /> <br />I-Rock Creek upstream of <br />Egeria Creek <br /> <br />2-Rock Creek downstream of <br />Egeria Creek <br /> <br />3-Rock Creek downstream of <br />Egeria Creek <br />@boundary <br /> <br />86 <br /> <br />95 <br /> <br />73 <br /> <br />75 <br /> <br />81 <br /> <br />AVerlll!:e <br /> <br />81 <br /> <br />85 <br /> <br />Averaging the ,mmml results of sampling and compari!lg 2002 with 2004 results Rock Creek <br />shows a slight overall improvement in beahh. Average scores have increased ttom 81 to 85 <br />indicating that the health of the stream is good. EJUlminAtion of the results of sampling stratified <br />for their location in the reach upstream or downstream ofEgeria Creek indil;lltes that <br />macroinvertebrate and stream health (as illustrated by the Biotic Condition Index) has shown <br />substantial improvement upstream of the Egeria Creek confluence and that Rock Creek below <br />the Egeria Creek confluence is presently in a state of only slight improvement. The Biotic <br />Condition Index for the area above Egeria Creek shows an improvement in score ttom 86 to 95 <br />putting this stream area in the excellent health category while the score below Egeria Creek <br />improved only two points keeping it in the Fair category. Downstream drift of organi!l1JlS plays an <br />important role in the rate ofre-establishment ofan impacted macroinvertebrate community. Rock <br />Creek above Egeria Creek is fed by a primarily free stone stream that has very Iittle beaver activity <br />or still water while the section ofEgeria Creek one mile above Rock Creek is dominated by very <br />old stable beaver ponds contAinirlg highly organic sediments. The quality (environmental <br />sensitivity) and abnndanre (nnmhers) of orglltlmn,. that drift downstream from stapding water <br />environment is known to be much lower than ttom a stream enviroTJtneTlt. It is normal for the <br />macroinvertebrate community in the lower section of Rack Creek to take a little longer to re- <br />establish than in the \lPPef section. We anticipate the improvement trend to continue Over time as <br />it has on other projects. <br /> <br />Overall macroinvertebrate sampling in<Ji...ates that the stream has benefitted ttom the restoration <br />that was accomplished. Biotic Condition Index scores that were realized are much better than <br />anticipated. Early indil'.srtinns are that substantial improvement to the health of the stilO<1Ul has <br />been achieved. <br /> <br />Comparison ofR2Cross evalnations in Rock Creek 1985-2004: <br /> <br />The State of Colorado uses the R2Cross methodology to predict the flows required to protect the <br />aquatic biota of a stream to a reasonable degree. This effort utilized a comparisons of the results <br />of a number of completed R2Cross stream cross sections over the period of record to determine <br />