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BASIS FOR DESIGN OF FW~1 Freshwater Pond No. 1 (FW#1) hes been designed to provide two (2) months storage capacity for potable and domestic water uses. This pond has a capacity of ten (10) acre- feet, an embankment height of 19.5 feet, and a surface area of 1.10 acres. The pond is located on the natural bench above the valley floor at an approximate elevation of 6,290 - feet. Normal surface runoff has been kept from entering Freshwater Pond No. 1 (FW#1) by providing a ditch upstream of the pond to intercept and carry the PMP assumption "B" storm flow to MB#1. This ditch keeps all nuisance flows from entering and combining with the raw water stored in the fresh water pond. A spillway section has been designed to pass any overland flows that may overtop this ditch and enter the pond. SPILLWAY D ESIG NS - Spillways have been sized using the broad crested wier equation, Q = CLH1'S. A ~~ coefficient "C", of 2.67 was assumed as this is the low end of the practical range. All spillways are to be constructed of riprap or gabions. The design head for each spillway has. been limited to 2.50 ft. Freshwater Pond Number 1 (FW#1) has a service spillway to (_, ensure that small inadvertent flows entering the pond are passed without relying on the emergency spillway. The individual plan sets include all pertinent hydrologic and spillway data. STABILITY PROGRAM DESCRIPTION The stability analysis for the proposed dams was performed using a slope stability computer program (SLOPE 11) developed by Geo Slope Programming, Ltd., Regina, Sas- katchewan. The Ordinary (Fellenius) Method and the Simplified Bishop Methods were used to compute stabt7ity factors of safety for each embankment's maximum cross section. Both methodologies use the method of slices and utilize the limit equilibrium theory to solve for the factor of safety. The principle difference between the two methods is the treatment of inter slice forces. The Ordinary Method assumes that inter - slice forces can be igonred while the Simplified Bishop Method assumes that the interslice forces act horizontally. Our results indicated that the Ordinary Method yielded lower. - factors of safety in all cases. Consequently for all subsequent trials on the given dam only w the Ordinary Method was used.