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<br />II <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />the fact that a residence is located immediately <br />downstream. 2) Inadequate height between the berm <br />crest and spillway, 3) embankment erosion protection <br />was minimal, and 4) muskrat habitation and <br />vegetative growth along the berm embankment and <br />crest. In 1988, restricted use of the reservoir was <br />approved, after the Town lowered the spillway to <br />provide 4 feet of freeboard. Muskrat and vegetation <br />mitigation was recommended. <br /> <br />According to the District Field Engineer, the dam <br />may be non-jurisdictional, since its official height <br />may be less than 10 feet. If capacity were <br />increased by raising the embankment, the dam would <br />become jurisdictional and Plans and Specs would have <br />to be submitted to the State Engineer. <br /> <br />Present Capacity and Depth. Depth measurements were <br />made on a rough grid pattern, with the water surface <br />at the lowered spillway level. Water depth varies <br />from 11 feet on the north end to less than 4 feet on <br />the south end. It would be desirable to partially <br />deepen the south end to reduce weed growth. <br />Approximate depth contours are shown on Figure <br />III-D. Using this data, reservoir capacity was <br />estimated to be approximately 9.6 million gallons. <br />However, the plant opertor believes the actual <br />volume is closer to 6 million gallons, based on his <br />winter flow records. For purposes of this report, a <br />total volume of 8.5 MG will be assumed. Since about <br />2 to 3 feet must be retained in winter to prevent <br />ice problems, the usuable volume is probably 8.0 MG <br />(24.5 AF). <br /> <br />Dam Classification. Design and construction <br />requirements depend in part on the dam's safety <br />classification. There are four classifications, <br />with Class I having the highest risk (and most <br />restrictions) and Class IV the least risk. The Town <br />reservoir is now rated Class III; it might possibly <br />be Class IV if the house at the based of the <br />embankment was not there. A dam break hazard <br />analysis would be needed to verify this. <br /> <br />Operational Problems. Vegetative growth in the <br />reservoir has been a problem during summer months, <br />along with stagnation. At times, the water has even <br />turned septic. Maintenance of the reservoir has <br />been partially limited because of the inability to <br />bypass the reservoir with water diverted from Gurley <br />Ditch, and the resultant need to have stored raw <br />water at all times to maintain required water <br />supply. <br /> <br />1II-4 <br />