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1.0 INTRODUCTION— BACKGROUND <br /> 1.1. PURPOSE <br /> During the overnight hours of April 26, 2014, a significant, localized thunderstorm occurred <br /> upstream of the canal operated by the Las Animas Consolidated Canal Company (LACC) <br /> and Consolidated Extension Canal Company (CECC, collectively both referred to as <br /> Company throughout the document). This storm created heavy runoff which flowed into the <br /> canal downstream of the main canal headgate through several uncontrolled and ungaged <br /> tributaries. These flows exceeded the capacity of the existing spillway structure at the river <br /> return, caused the structure to be overtopped and undermined, and resulted in catastrophic <br /> failure of the existing structure. Figure 1 shows the condition of the structure after the failure. <br /> Due to the localized nature of the thunderstorm, the Company superintendent was unaware <br /> of the upstream storm or canal failure until reduced canal flows indicated a breach early the <br /> next morning. <br /> LACC and CECC undertook immediate emergency repairs to get the canal back in service <br /> as quickly as possible. Irrigation season was well underway at the time of the incident and <br /> Company water users already had significant investments in crops under irrigation. The <br /> emergency repair eliminated the canal breach and provided for temporary level/flow control <br /> upstream of the Company measurement flume. The emergency repair allowed the Company <br /> to remain operable during the 2014 irrigation season, but it does not include the ability to <br /> bypass sediment which has already accreted in the upstream channel in significant quantity <br /> since the failure. Additionally, removal of debris from the level/flow control spillway is <br /> difficult for the Company's superintendent. Finally, inspection of the portion of the structure <br /> which did not fail indicated several precursors of potential failure, including evidence of <br /> piping under the concrete structure and significant concrete erosion around the canal control <br /> gates. Examination of the concrete in the failed portion of the structure indicates that the <br /> overall structure was constructed with little (if any) structural steel, suggesting that the <br /> remaining structure has little ability to resist further deterioration. <br /> September 2014 Draft <br /> Page 11 <br />