Mountain View Municipal Code Div. 3 Site Improvements, Utilities, and Limitations

All proposed development in flood hazard areas shall be reviewed to determine that:

a. Such proposals are consistent with the need to minimize flood damage and will be reasonably safe from flooding.

b. Where the proposed development has more than fifty (50) lots or is larger than five (5) acres and base flood elevations are not included on the FIRM, the base flood elevations determined in accordance with Sec. 48.12.10.a of this Chapter.

c. All public utilities and facilities, such as sewer, gas, electric, communications and water systems, are located and constructed to minimize or eliminate flood damage.

d. Adequate drainage is provided to reduce exposure to flood hazards; in Zones AH and AO, adequate drainage paths shall be provided to guide floodwater around and away from proposed structures.

(Ord. No. 6.2025, § 2, 9/9/25.)

All new and replaced sanitary sewer facilities, private sewage treatment plants (including all pumping stations and collector systems) and on-site waste disposal systems shall be designed in accordance with Chapter 7 , ASCE 24, to minimize or eliminate infiltration of floodwaters into the facilities and discharge from the facilities into flood waters, and impairment of the facilities and systems.

(Ord. No. 6.2025, § 2, 9/9/25.)

All new and replaced water supply facilities shall be designed in accordance with the provisions of Chapter 7 , ASCE 24, to minimize or eliminate infiltration of floodwaters into the systems.

(Ord. No. 6.2025, § 2, 9/9/25.)

Development, site improvements and land-disturbing activity involving fill or regrading shall not be authorized in the floodway unless the floodway encroachment analysis required in Sec. 48.12.15.a of this Chapter demonstrates the proposed work will not result in any increase in the base flood level during occurrence of the base flood discharge.

(Ord. No. 6.2025, § 2, 9/9/25.)

Subject to the limitations of this Chapter, fill shall be designed to be stable under conditions of flooding, including rapid rise and rapid drawdown of floodwaters, prolonged inundation and protection against flood-related erosion and scour. In addition to these requirements, when intended to support buildings and structures, fill shall comply with the requirements of the building code. The placement of fill intended to change base flood elevations, change floodway boundaries or change boundaries of flood hazard areas shown on FIRMs shall be subject to the requirements of Sec. 48.12.20 of this Chapter.

(Ord. No. 6.2025, § 2, 9/9/25.)

In coastal high hazard areas and Coastal A Zones:

a. New buildings shall only be authorized landward of the reach of mean high tide.

b. The use of fill for structural support of buildings is prohibited.

(Ord. No. 6.2025, § 2, 9/9/25.)

Nonstructural fill or alteration of sand dunes in coastal high hazard areas (Zone V/VE) and Coastal A Zones shall be permitted only when authorized by appropriate federal, state or local authorities. Where permitted, such fill or alterations shall comply with the following, as applicable:

a. Minor grading and the placement of minor quantities of nonstructural fill shall be permitted for landscaping, and for drainage purposes under and around buildings.

b. Nonstructural fill with finished slopes that are steeper than one (1) unit vertical to five (5) units horizontal shall be permitted only when an analysis prepared by a qualified registered design professional demonstrates no harmful diversion of floodwaters or wave run-up and wave reflection that would increase damage to adjacent buildings and structures.

c. Alteration of sand dunes shall be permitted only when the engineering analysis required by Sec. 48.12.15 (d) of these regulations demonstrates that the proposed alteration will not increase the potential for flood damage.

d. Sand dune construction and restoration of sand dunes under or around elevated buildings are permitted without additional engineering analysis or certification of the diversion of floodwater or wave run-up and wave reflection when the scale and location of the dune work are consistent with local beach-dune morphology and the vertical clearance is maintained between the top of the sand dune and the lowest horizontal structural member of the building.

(Ord. No. 6.2025, § 2, 9/9/25.)

Development and site improvement activities other than buildings and structures, where located in coastal high hazard areas (Zone V/VE) and Coastal A Zones, shall be permitted only when authorized by appropriate federal, state or local authorities. In addition, development and site improvement activities shall be permitted when located outside the footprint of, and not structurally attached to, buildings and structures and when analyses prepared by qualified CA Licensed Civil Design Professionals demonstrate no harmful diversion of floodwaters or wave run-up and wave reflection that would increase damage to adjacent buildings and structures. Such development and site improvement activities include, but are not limited to:

a. Bulkheads, seawalls, retaining walls, revetments, and similar erosion control structures.

b. Solid fences and privacy walls, and fences prone to trapping debris, unless designed and constructed to fail under flood conditions less than the base flood or otherwise function to avoid obstruction of floodwaters.

c. On-site sewage treatment and disposal systems, including mound systems.

(Ord. No. 6.2025, § 2, 9/9/25.)