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<br />4. Freeboard is a minimum of three percent of the embankment <br />height, but not less than five feet. <br /> <br />5.7.11.5 The minimum acceptable pseudo-static stability analysis factor of safety is <br />1.0, and shall be attainable using a pseudo-static load coefficient of one-halfthe <br />predicted peak bedrock acceleration (g's), but not less than 0.05. <br /> <br />5.7.11.6 For those High Hazard darns and Large Significant Hazard dams, for which <br />a pseudo-static analysis is not appropriate, as determined by Rule 5.7.11.4, a <br />deformational analysis shall be performed in a manner acceptable to the State <br />Engineer. The freeboard remaining after deformation ofthe dam shall not be less <br />than three feet. <br /> <br />5.8 Design Report - A design report shall include information sufficient to evaluate the design of <br />the darn and appurtenances, including references and page numbers, to support any assumptions or <br />criteria used in the design. The design report shall contain information to show that the following <br />have been met: <br /> <br />5.8.1 Filter design for all chimney drains, filter blankets, and toe drains must be acceptable <br />to the State Engineer. The use of geotextiles as a filter material is not allowed where drains <br />or filters are not easily accessible for repair or where excavation of the drain creates a threat <br />to safety of the dam. <br /> <br />5.8.2 Underdrains and collection pipes shall be constructed using noncorrodible materials. <br /> <br />5.8.3 Rock riprap shall be well graded, durable and sized to withstand design wave action or <br />channel velocities, and shall be placed on a well-graded pervious sand and gravel bedding <br />or geotextile fabric. Soil cement for erosion protection may be used in lieu ofrock riprap, <br />but shall be designed and constructed in accordance with standards acceptable to the State <br />Engineer. Slope protection for wave action is required to be provided on the entire upstream <br />face of the dam, unless lesser coverage is justified based on engineering analysis and . <br />reservoir operational criteria and approved by the State Engineer. <br /> <br />5.8.4 All outlet systems shall be designed and installed in a manner acceptable to the State <br />Engineer and shall meet the following criteria: <br /> <br />5.8.4.1 The outlets for High Hazard dams shall be capable of releasing the top five <br />feet of the reservoir capacity in five days, and for all other classes of dams as <br />required by the State Engineer. In addition, outlets shall be capable of passing <br />inflow to the reservoir with a minimum of ten feet of head, in order to meet the <br />demands of downstream senior water rights and the owner's release requirements. <br />The minimum size required for outlet conduits and controls is 12 inches. <br /> <br />5.8.4.2 All principal outlets connected to a pipeline shall have a by-pass valve that <br />will meet the capacity criteria as defined in Rule 5.8.4.1. <br /> <br />21 <br />