(1) “Breach” refers to an opening through a dam or critical appurtenant structure.

(2) “Breach height” refers to the vertical distance of the dam or critical appurtenant structure that must be breached in the model. The breach height of a dam shall be measured from the upstream toe or downstream toe, whichever elevation is higher, to the maximum possible storage elevation. The breach height of a critical appurtenant structure is its height, as defined in section 335.2(a)(3)(B).

(3) “Critical appurtenant structure” refers to a barrier or hydraulic control structure that impounds the same reservoir as the dam and is 25 feet or more in height, impounds a minimum of 5,000 acre-feet of water at the maximum possible storage elevation, or that the department determines poses a significant or higher downstream hazard potential per section 335.4(a). Typical critical appurtenant structures include emergency spillways, gated spillways, and saddle dams.

(4) “Critical facilities” refers to law enforcement facilities, fire stations, schools, hospitals, prisons, and major roads.

(5) “Dam” has the same meaning as provided in section 6002 of the Water Code.

(6) “Dam system” refers to a dam and all critical appurtenant structures that impound the same reservoir.

(7) “Dynamic routing” refers to hydraulic flow routing based on the shallow water equations to compute changes in discharge, velocity, and stage with respect to time at various locations along a watercourse.

(8) “EAP” refers to an emergency action plan as described in section 8589.5 of the Government Code.

(9) “Failure scenario” refers to the modeled simulation of a breach of a dam or critical appurtenant structure that results in an unintended release of the impoundment.

(10) “FEMA P-946” refers to the Federal Emergency Management Agency's “Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures,” dated July 2013.

(11) “Flood wave arrival time” refers to the elapsed time from the initiation of the failure scenario until the arrival of the leading edge of the flood wave.

(12) “Geospatial file” refers to a digital file containing data that is geographically referenced, typically in vector or raster format, as projected in NAD 1983 Teale (California) Albers per section 335.12(g).

(13) “Hydraulic model” refers to a computer model used to simulate the spatial and temporal changes of water depth and velocity conveyed through a watercourse.

(14) “Hydrograph” refers to a graphical representation of flow as a function of time.

(15) “Inundation area” refers to the area downstream of the dam or critical appurtenant structure that would experience a rise of one foot or greater in water surface elevation as the result of a failure scenario.

(16) “Inundation boundary” refers to the perimeter of the inundation area.

(17) “Inundation map” refers to a map showing the impacts of a failure scenario, such as where and when flooding would occur, and may contain multiple sheets.

(18) “Inundation map sheet” refers to a page in an inundation map.

(19) “Maximum possible storage elevation” refers to the maximum reservoir elevation to which water can be physically impounded without spilling. In most cases, this is the certified storage elevation. When a reservoir is restricted below the spillway, this is the elevation of the spillway crest.

(20) “NAVD88” refers to the North American Vertical Datum of 1988 computed by the National Geodetic Survey.

(21) “Owner” has the same meaning as provided in section 6005 of the Water Code.

(22) “PDF” refers to a portable document format file.

(23) “Projection” refers to a method by which the curved surface of the Earth is portrayed onto a flat surface.

(24) “Raster” refers to a data format that represents geographic information as a grid of cells, where each cell contains a value.

(25) “Storm-induced loading condition” refers to the meteorological conditions before and during the modeled breach of the dam or critical appurtenant structure when the reservoir is at or above the maximum possible storage elevation and the inundation boundary is greater than that of a sunny-day loading condition due to a rain or flood event.

(26) “Sunny-day loading condition” refers to the meteorological conditions before and during the modeled breach of the dam or critical appurtenant structure at the maximum possible storage elevation with non-flood season inflow.

(27) “Toe” refers to the junction of the slope of a dam or critical appurtenant structure with the natural ground surface.

(28) “Two-dimensional hydraulic model” refers to a hydraulic model in which variables such as velocity and depth vary in two horizontal directions along a watercourse.

(29) “Vector” refers to a data format that represents geographic information as point, line, or polygon features.