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Animas -La Plata Project <br />Feb 13, 2013 Draft Transfer Inspection Report <br />TRANSFER ISSUE <br />STIPULATION <br />Guard gate limit switches <br />Reclamation will install a splash guard to protect gate indicator <br />are exposed to gate <br />stem limit switches from gate chamber dome seepage. <br />chamber seepage <br />Gate chamber access hatch <br />Reclamation will modify hatch to permit closing if the ladder grab <br />cannot close over ladder <br />bar is extended. <br />grab bar <br />B. Ridges Basin Dam Access Road <br />Access to Ridges Basin Dam is from County Road 213 via a gravel surfaced access road. The first <br />section of the road, from CR 213 to the Wheeler crossing, is owned by the United States (fee <br />simple title). This road section is multi -use for gas companies, property owners, CWP, and <br />others. Maintenance of this section of the road is the responsibility of Chevron, U.S.A., as long <br />as oil and gas production occurs. The road from just above the Wheeler crossing to the dam is <br />secured and is exclusive to Reclamation and its assigns, with limited access by other entities. <br />Accessing the dam and the control house requires passage through several security gates, <br />including: two medium -duty steel pipe gates; a heavy -duty crash - certified, horizontal swing arm, <br />barrier system; and an automated vertical pivot gate. The access road also includes numerous <br />drainage improvements and channel crossings including, but not limited to, corrugated metal <br />culverts, concrete box culverts, grouted riprap channels, and appurtenant drainage ditches. <br />C. Outlet Works <br />The outlet works is located in the left abutment of the dam and consists of an intake approach <br />channel, intake structure, intake trashrack, intake bulkhead seat, upstream tunnel, gate <br />chamber, downstream tunnel, control room, gatehouse, and discharge channel. The upstream <br />portion is a concrete -lined 7.5' diameter 665' long tunnel. The gate chamber is located within <br />the left abutment a few feet upstream of the dam axis and contains a 4' x 6' guard gate acting as <br />an emergency gate. The downstream tunnel has a reinforced concrete lining, connecting the <br />gate chamber to the control house. The tunnel lining is an 11' diameter horseshoe about 682 <br />feet long. A 66" diameter steel pipe within the tunnel conveys the water from the gate <br />chamber, to the gatehouse. <br />The control house includes access to the downstream tunnel, the control room, the steel pipe <br />trifurcation (includes a 66" diameter steel pipe controlled by a 60" jet -flow gate; a 48" diameter <br />steel pipe with a 48" butterfly valve controlled by 48" inline sleeve valve; and a 36" diameter <br />steel pipe that terminates just downstream of the control house with a blind flange and 36" <br />butterfly valve intended for future water distribution). <br />Immediately downstream of the control house, a 95' long by 20' wide reinforced concrete -lined <br />stilling basin and a 62.5' long by 20' wide channel of grouted riprap extend to a reinforced <br />concrete inlet structure leading to two 48" diameter precast concrete pipes (which are located <br />beneath the dam access road). The stilling basin downstream of the control house is a (Type 1) <br />structure and is intended to dissipate releases (via a hydraulic jump) up to 360 cfs. Releases <br />greater than 360 cfs will overtop and eventually breach the downstream access road. A baffled <br />outlet structure, located at the downstream ends of the precast pipes will dissipate releases as <br />they are passed into Basin Creek. <br />Transferred Works Inspection 4 Animas -La Plata Project <br />