Section 335.2 - Definitions(a) Unless the context clearly requires otherwise, as used in this article, the terms below shall have the meanings noted:(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. (A) A critical appurtenant structure may contain multiple water barriers, including but not limited to gates, flashboards, and concrete monoliths.(B) The height of a critical appurtenant structure shall be measured from the upstream toe or downstream toe, whichever elevation is higher, to the maximum possible storage elevation, except for the following cases: 1. For a structure comprising gates constructed on a concrete control structure, such as a spillway with multiple radial gates, its height shall be measured from the upstream toe of the concrete control structure to the maximum possible storage elevation.2. If gates are affixed to a concrete dam, the height shall be measured from the base of the gates to the maximum possible storage elevation.(C) A penstock or low-level outlet shall be considered a critical appurtenant structure if the department determines it poses a significant or higher downstream hazard potential, as defined in section 335.4(a).(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.Cal. Code Regs. Tit. 23, § 335.2
1. New section filed 10-19-2017 as a deemed emergency pursuant to Water Code section 6162; operative 10-19-2017 (Register 2017, No. 42). A Certificate of Compliance must be transmitted to OAL by 4-17-2018 or emergency language will be repealed by operation of law on the following day.
2. New section refiled 4-16-2018 as a deemed emergency pursuant to Water Code section 6162; operative 4-18-2018 (Register 2018, No. 16). A Certificate of Compliance must be transmitted to OAL by 7-17-2018 or emergency language will be repealed by operation of law on the following day.
3. New section, including amendment of section and NOTE, refiled 7-12-2018 as an emergency pursuant to Water Code section 6162; operative 7-18-2018 (Register 2018, No. 28). A Certificate of Compliance must be transmitted to OAL by 10-16-2018 or emergency language will be repealed by operation of law on the following day.
4. Certificate of Compliance as to 7-12-2018 order, including amendment of section, transmitted to OAL 10-16-2018 and filed 11-29-2018; amendments effective 11-29-2018 pursuant to Government Code section 11343.4(b)(3) (Register 2018, No. 48). Note: Authority cited: Sections 6078 and 6162, Water Code. Reference: Section 8589.5, Government Code; and Sections 6002, 6002.5, 6004.5, 6005, 6007.5, 6008 and 6161, Water Code.
1. New section filed 10-19-2017 as a deemed emergency pursuant to Water Code section 6162; operative 10-19-2017 (Register 2017, No. 42). A Certificate of Compliance must be transmitted to OAL by 4-17-2018 or emergency language will be repealed by operation of law on the following day.
2. New section refiled 4-16-2018 as a deemed emergency pursuant to Water Code section 6162; operative 4-18-2018 (Register 2018, No. 16). A Certificate of Compliance must be transmitted to OAL by 7-17-2018 or emergency language will be repealed by operation of law on the following day.
3. New section, including amendment of section and Note, refiled 7-12-2018 as an emergency pursuant to Water Code section 6162; operative 7/18/2018 (Register 2018, No. 28). A Certificate of Compliance must be transmitted to OAL by 10-16-2018 or emergency language will be repealed by operation of law on the following day.
4. Certificate of Compliance as to 7-12-2018 order, including amendment of section, transmitted to OAL 10-16-2018 and filed 11-29-2018; amendments effective 11/29/2018 pursuant to Government Code section 11343.4(b)(3) (Register 2018, No. 48).