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Last Chance Ditch <br />CFS. Preliminary calculations indicate that t�vo 3 foot by 3 foot headgates �vill <br />flow approximately 76 CFS �vith the conservative half foot of head. This same <br />gate configuration ���ill flow approximately 92 CFS with 0.75 foot of head. An <br />additional headgate opening will be installed in the main channel headcvorks <br />structure. It �vill be located bet�veen the two proposed headgates and will be <br />sealed until needed. This �vill allow for an optional third headgate to be <br />installed at a later date thus allo��-ing Last Chance to take their entire allotment <br />of water. <br />Project Description <br />The Last Chance Ditch Company has been maintaining the existing headworks <br />structures for more than one hundred years. To ensure the safety of those <br />downstream from the ditch, and to ensure shareholders are able to utilize their <br />decreed water allotment, replacement of the head�vorks structure is necessary. <br />Atternatives Evaluated <br />l. Take no action. <br />2. Replace the existing structure �Tith a similar headgate. <br />3. Replace the existing structure with a similar headgate and flumegate. <br />4. Replace the existing structure with headgates and an optional overshot <br />gate for river return flo�vs. <br />5. Replace the existing dam and upgrade the structure �vith options #2 or <br />#3. <br />An evaluation of the alternatives: <br />1. Take no action. <br />If the replacement of the Last Chance Ditch head�vorks is not pursued, the <br />ditch w�ill continue to be unable to take the full amount of allotted water. The <br />expensive annual costs of building up the dam and maintaining the head�vorks <br />�vill continue. This is not a good option for the future of the ditch company. <br />2. Replace the existing structure with a similar headgate. <br />The existing structure �vould be removed and reconstructed with a concrete <br />structure similar in shape and style. This would include removing the old <br />structure and performing �t�ork to construct the necv structure. <br />Included in this option are t«-o headgates that ���ould allo��� for slightly more <br />ast ance itc ompany oan easi i ity tu y age o <br />