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~ III IIIIIIIIIIIII III ~ <br />~; ~~, Lidstone and Associates. Inc. <br />Aagita{ AC <br />Exyinee~iny, Geo~ctq~ & Wuter Rewyrce Consu~lanls <br />December 4, 2001 <br />RECEIVED <br />Jeffrey W. Schwarz DEC 1 1 2001 <br />Massey, Semenoff, Schwarz & Bailey <br />Hudson's Bay Centre <br />1600 Stout S[ree[ Oiuisi0n of Minerals and GeoloAY <br />Suite 1700 <br />Denver. CO 80202 <br />Re: DMG Request for Additional Information Mobile Premix Concrete, Inc., Howe Pit (Permit <br />M-78-052) <br />Dear Mr. Schwarz: <br />A[ your request, 1 have reviewed the State of Colorado, Division of Mines and Geology letter of <br />November 21, 2001. Brian Wood and I met with Tom Schreiner, Allen Sorenson, and Carl Mount on <br />Friday, November 30, 2001 and presented the requested modeling results. During this meeting we <br />discussed the major issues associated with our forensic analysis of the May ~, 2001 bank failure and <br />presented our professional opinion that the bank failure and resultant downstream damage was not related <br />to existing location of the Bull Seep. <br />With this letter and enclosures. Lidstone and Associates, Inc. (LA) responds [o the Stale of Colorado <br />Division of Mines and Geology (DMG) letter of November 21, 2001 (Schreiner [o Hickman). Tom <br />Schreiner's original letter outlined six points. I am addressing Points 2, 3 and possibly 4. <br />Point 2 <br />[t is my understanding that the original flood control levee was constructed as a WPA levee sometime in <br />the late 1930s or 1940s. Following the construction of the Brantner Diversion Structure, the farmers <br />adjacent to the area sued the Brantner Diversion Ditch Company, alleging that the Diversion caused flood <br />damage to their property. Some of the Flood scars from a 1949 went can be seen on the June 21, 1950 <br />photo (see Figure 2.1). I assume that the 1949 Flooding and the farmers' concerns led to additional <br />construction and/or extension of the WPA Flood control levee in a northward direction. <br />I have previously submitted the 190 aerial photograph in a digital manner to Allen Sorenson. A review <br />of the June 190 aerial photograph suggests the presence of a ditch/swale along the inboard side of the <br />levee. My assumption is that the individuals who constructed the levee, borrowed "fill" material from the <br />inboard side of the levee. The photo doesn't suggest any other nearby borrow areas. This photo indicates <br />that the levee extension was under construction as of the date of this photo (6/21/1950). One can see <br />what appears to be a flow line and sedimentation near the downstream terminus of this structure. This <br />same area is now referred to as the "intersection of the Bull Seep Drain and Bull Seep Slough". <br />This feature is also documented in the pre-disturbance mapping of [he area as shown in Mobile Premix <br />Concrete Permit (N1-78-052). Please reference the Drainage Plan Map (Sheets I and ?). These sheets are <br />4025 Automation Way, Building E. Fort Collins. Colorado 80525-3448 715 E. Roosevelt Riverton, Wyoming 82501-3662 <br />(970) 223-0705 fax: (970) 22J-1706 a-mail: watena"]lidstone.com (307) 856-5271 fax: (3071856-5281 a-mad: riverton(allidslone.com <br />