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<br />" 1") (; (, <br />",IV"" L-.. :.J 0 <br /> <br />on April 16, 2004. The USGS gauging station 09239500 on the Yampa River in <br />Steamboat Springs, Colorado lists the flow in the river on that day at 395 cfs. At <br />this level the flow over both the Charlie's and D-Hole structures would be far <br />too powerful and swift for a surveyor to collect data points at the center <br />channel invert. Indeed, the Emerald Mountain Survey data, on which the <br />HEC-RAS model is based, presents no data points for a width of more than <br />30 feet at the Charlie's Hole and more than 22 feet at the D-Hole. This is <br />further confirmed by the surveyor. If, as Mr. Browning claims, this survey <br />data was used to create the HEC-RAS model, then presumably the channel <br />invert that Mr. Browning labels as RlCD is invalid. Thus, Mr. Browning's <br />HEC-RAS model is also not valid because the channel invert elevation used is <br /> <br />not the channel invert elevation at ail, but rather the water surface elevation <br /> <br />at 395 cfs. <br /> <br />. It is also my opinion that Mr. Browning's own model most likely demonstrates <br />that the structures at Charlie's Hole and the D-Hole have actually caused a <br />decreased water surface elevation in this section of the river. To understand the <br />reasoning for this claim it is important to understand the differences between the <br />Figures that Mr. Browning presents in his Attachments F and G. In attachment F, <br />Mr. Browning presents the channel invert elevations prior to the construction of <br />the fish habitat structures and the Boating Park from the earlier FEMA work. <br />Each FEMA data point of the channel invert corresponds to a surveyed cross- <br />section. These dimensions were used to create a HEC- RAS model by FEMA that <br />serves as the governmental dimensions of record for the Yampa Riverbed. <br /> <br />The Figure in Attachment G was created because Mr. Browning found that the <br />actual cross-sections shown roughly at stations 997500 and 997000 were different <br />than those shown in the FEMA model. Mr. Browning made the assumption that <br />the FEMA model was inaccurate and that a more appropriate model for what was <br />in the river prior to the construction of the Boating Park was a survey made after <br />the Boating Park had been constructed. When these dimensions are used to create <br /> <br />13 <br />