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OO~t20 APPENDIX D-RECLAMA TION RESERVOIR DATA DEFINTIONS ,.,eral vam design and reservoir operation utilize reservoir capacity and water surface elevation data. To ensure uniformity in the establishment, use, and publication of these data, the following standard definitions of water surface elevations and reservoir capacities are used throughout Reclamation. Reservoir capacity as used here is exclusive of bank storage capacity. Water Surface Elevation Definitions Maximum Water Surface.-The highest acceptable water surface elevation with all factors affecting the safety of the structure considered. It is the highest water surface elevation resulting from a computed routing of the inflow design flood through the reservoir under established operating criteria. This surface is also the top of the surcharge capacity. Normal Water Surface.-The highest elevation that water is normally stored, or that elevation which the reservoir should be operated for conservation purposes. Top of Exclusive Flood Control Capacity.- The reservoir water surface elevation at the top of the reservoir capacity allocated to exclusive use for the regulation of flood inflows to reduce damage downstream. Maximum Controllable Water Surface Elevation.-The highest reservoir water surface elevation at which vity flows from the reservoir can be completely shut off "-",,,iJ Top of Joint Use Capacity.-The reservoir water surface elevation at the top of the reservoir capacity allocated to joint use, i.e" flood control and conservation purposes. Top of Active Conservation Capacity.-The reservoir water surface elevation at the top of the capacity allocated to the storage of water for conservation purposes only. Top of Inactive Capacity.- The reservoir water surface elevation below which the reservoir will not be evacuated under normal conditions. Top of Dead Capacity.- The lowest elevation in the reservoir from which water can be drawn by gravity. Stream bed at the Dam Axis. -The elevation of the lowest point in the streambed at the axis or centerline crest of the dam prior to construction. (This elevation normally defines the zero for the area-capacity tables). Surcharge Capacity.- The reservoir capacity provided for use in passing the inflow design flood through the reservoir, It is the reservoir capacity between the maximum water surface elevation and the highest of the following elevations (I) top of exclusive flood control capacity, (2) top of joint use capacity, or (3) top of active conservation capacity. Total Capacity.-The reservoir capacity below the highest of the elevations representing (I) the top of exclusive flood control capacity, (2) the top of joint use capacity, or (3) the top of active conservation capacity. In the case of a natural lake which has been enlarged, the total capacity includes the dead capacity of the lake. Total capacity is used to express the total quantity of water which can be impounded and is