CT2015-003 Increase Approval Letter

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North Poudre Irrigation Company Agenda Item 19a January 25-26, 2016 Board Meeting(Updated January 27, 2016) Page 2 of 5 Background The Company's service area includes approximately 28,000 irrigated acres of farm land in northeastern Larimer County extending from Ft. Collins to north of Wellington. The Company operates 21 storage reservoirs, five flood control dams, and approximately 200 miles of ditches. The irrigated acreage within the service area is primarily used to grow corn, sugar beets, soybeans, hay, and feed crops. Reservoir No. 4 is an off-stream reservoir with a drainage basin of approximately 320 acres. The dam was constructed in the late 1880s, enlarged in the 1920s, and the outlet works were replaced in the late 1950s. The reservoir has decreed water rights allowing storage of 1,781 acre feet (AF) of water at full capacity with a 918 AF refill right. The reservoir is used to irrigate approximately 150 acres of land downstream, in exchanges to other irrigation companies, and for mitigation of water losses on other portions of the Company's system. The SE0 restricted the reservoir due to aging outlet works, an inadequate spillway, and seepage at the toe of the dam over thirty years ago. Under this restriction the reservoir capacity is approximately 1,107 AF, representing a storage loss of 674 AF. Though the Company has long desired to make the repairs necessary to remove the storage restriction, other projects continued to take precedence. However, the aging outlet works have now deteriorated to the point that the entire reservoir is at risk if these repairs are not performed soon. Water Rights The water rights impacted by this project include TABLE 1: IMPACTED WATER RIGHTS Name Amount (AF) Appropriation Date Adjudication Date Reservoir No 4 1,074 11/1/1889 12/9/1904 Reservoir No 4 707 5/15/1903 4/22/1922 Reservoir No 4 (Refill) 918 12/31/1921 9/10/1953 Average annual delivery of the Company is 44,400 AF. Project Update Final design has been completed by Ron Slosson, P.E., and was approved by the SE0 for construction. During the SEO's design review, the Company was notified that there was a possibility of the dam classification changing from a significant to a high-hazard dam in the future. In response, the Company decided to re-design the spillway so it would pass the Probable Maximum Precipitation (PMP) flood, as would be required for a high-hazard classification dam. It is estimated that this change added at least $100,000 to construction cost for drop and overflow structures in the spillway, in addition to extra design engineering fees. Construction was split into three phases. The first phase included the removal of cottonwood trees that had taken root within the reservoir's high water line as a result of the Company not storing its full decree for the past thirty years. A local professional arborist was hired to conduct a study and inventory the trees. The study identified winter as the best season to remove the trees to minimize wildlife impacts, and found that more trees than originally planned would not survive if the reservoir were allowed to store its full decree. This work was bid separately due to the specialized nature, timing, and size of the work. This phase was successfully completed in winter 2014 but exceeded the original estimate by $110,000. The second phase of the Project includes repairs to the dam, outlet works, and spillway. Four contractors submitted bids for this phase, ranging from $1,556,000 to $2,366,000. Zak Dirt was the low bidder, was determined to be qualified, and was therefore the selected contractor. It was noted in all