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Cucharas Feasibility Study| Introduction 1 INTRODUCTION The Huerfano – Cucharas Irrigation Company (HCIC), located in southeast Pueblo County, owns and operates the Cucharas No. 5 Dam and Reservoir. The dam is located in northern Huerfano County, on the Cucharas River, approximately 16 miles northeast of the City of Walsenburg. In May of 1987, while the reservoir was full to the spillway crest, the dam developed extensive seepage along the toe abutments of the dam. It was discovered that the upstream concrete facing on the rock fill dam had failed and was allowing large quantities of seepage flow to occur through the rock fill embankment. The reservoir was lowered and the concrete facing repaired, but the State Engineer’s Office (SEO) restricted storage to gauge height 100 feet or approximately 7,500 acre‐feet of storage. The storage restriction has remained in effect since 1988 and there is a suspense date of October 1, 2010 imposed by the SEO to either rehabilitate the existing dam, replace it with a new dam or a zero, no storage restriction will be imposed followed by an order to breach the dam and remove the hazard it represents. The dam has performed adequately at the restricted level with only moderate increases in seepage flow at higher storage levels being recorded, but the spillway is significantly inadequate and there remain many unknowns concerning the condition of the embankment and foundation. The purpose of this feasibility study is to select a financially possible alternative that would prevent a zero storage restriction from being imposed and maintain at least some storage in the reservoir as a first phase in project development. This first phase was previously reviewed in a different format and approved by the CWCB board. HCIC applied for a loan from the CWCB Water Project Loan Program in the amount of 90% of the eligible project costs to fund the project. The remaining 10 percent and loan repayment will be paid through special assessments to HCIC members. That first phase loan was for $1,622,060. Through September 25, 2010 $467,000 has been spent. The difference between the previously approved loan and the intent of the project now has shifted to include future improvements that will add more water and modernize the dam back to full capacity. More discussion on the future plans for the irrigation company is attached. The second phase of the project would restore the Cucharas Reservoir back to a 40,000 acre‐foot capacity. The vision of HCIC is to keep irrigated agriculture in place and enable it to become a partner to provide water supplies for other uses that could keep a revenue stream intact that justifies rebuilding the HCIC system back to full operational status. This vision would prepare HCIC to provide raw water supplies for a local metropolitan water district. Agriculture would provide a buffer supply and be a partner in the metro district. The second phase of the loan application would be for one of two options; 1) replacing the existing dam with a completely new downstream Roller Compacted Concrete (RCC) structure, or 2) rehabilitating the existing rock fill dam to meet current dam safety criteria. A) STUDY AREA AND PROJECT DESCRIPTION The Cucharas No. 5 Dam is located in northeastern Huerfano County on the Cucharas River, approximately 16 miles northeast of the City of Walsenburg. The dam is a 145‐foot high rock fill dam that has undergone several enlargements since the original construction in 1914. The reservoir has a capacity of 35,395 acre‐feet to the spillway crest elevation of 5766.0 feet MSL, gauge height 120.5 ft. based on an October 2002 survey completed by Clyde B. Young &