(a) An inundation map shall be prepared for each failure scenario as described in section 335.6. Inundation maps must contain the following model outputs as rasters, contours, points, or cross-sections at appropriate time and space intervals displayed over current aerial imagery:
- (1) Inundation boundary,
- (2) Flood wave arrival time,
- (3) Maximum depth, and
- (4) Maximum velocity.
- (b) If using a raster for items in section 335.10(a), the opacity shall be adjusted to display the underlying aerial imagery.
- (c) The inundation boundary shall be displayed as a one-foot maximum depth, except where the flood wave would be confined to a channel or canyon, and where the flood wave no longer poses a threat to life or critical facilities.
(d) General information. Each inundation map sheet shall contain the following information:
- (1) The name of the dam, the department's dam number, the national dam ID number, and the county in which the dam is located.
- (2) The meteorological loading condition. Identify whether a sunny-day or storm-induced loading condition is depicted. If a storm-induced loading condition is depicted, note the return period of the storm or the term “Probable Maximum Flood,” as applicable.
- (3) Sediment. If the failure scenario depicts the effects of sediment release, note “Includes reservoir sediment release.”
- (4) Label identifying the dam.
- (5) Symbols and a corresponding legend that identifies all critical facilities in the inundation area and within the mapped extent.
- (6) Labels identifying the downstream channels and flood control features within the inundation area, such as dams, levees, canals, rivers, streams, bypasses, weirs, pumps, and control structures.
- (7) Boundary delineations identifying the city, county, or other governmental agency jurisdictional boundaries affected by the inundation area.
- (8) An arrow indicating north.
- (9) An appropriate scale bar and the stated map scale.
- (10) Vertical elevation datum specified as NAVD88.
- (11) If applicable, an index showing the relationship of the map sheet to the other map sheets.
- (12) The preparation date of the map.
- (13) The simulation date of the model.
- (14) The signature, seal, and license number of the California-licensed professional civil engineer responsible for preparing the map.
(15) A statement that includes:
- (A) The information shown is approximate and should be used as a guideline for emergency preparation and response.
- (B) Security-sensitive infrastructure may not be shown on this map.
- (16) For flood waves that are confined within a channel but not shown within the inundation boundary as allowed by section 335.10(c), a statement indicating high flows may continue beyond the inundation boundary.
- (17) Labels identifying low-lying areas where the flood recession is expected to be slow and affect lives or critical facilities.
(e) Map Layout. All inundation maps shall be prepared at a scale and quality that enables a person familiar with the area to clearly comprehend an aerial view of the extent of flooding. A map scale such as that described in Section 11.3.3 of FEMA P-946 may be applied.
Note: Note: Authority cited: Sections 6078 and 6162, Water Code. Reference: Section 8589.5, Government Code; Sections 6160 and 6161, Water Code; and Section 6700, Business and Professions Code.
History
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, including amendment of subsection (c)(15); 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 renumbering of former section 335.10 to section 335.12, renumbering of former section 335.14 to section 335.10 and amendment of section and Note, 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).