Sacramento County Zoning Code § 906-06 Standards for New

All development plans and grading plans shall:

A. Identify special or local flood hazard areas and the elevation of the base flood
B. Provide the elevation of proposed buildings and pads, and ensure the proposed pads will be at least one foot above the base flood elevation and meet minimum floor requirements per section 906-02. If the site is filled above the base flood elevation, the constructed pad elevations shall be as-built surveyed by a registered professional engineer or surveyor, compacted in accordance with 906-05 (C), and certified results shall be provided to the Floodplain Administrator for review and submittal to FEMA for map revision.
C. Be designed in accordance with this Code and the County Improvement Standards to minimize flood damage.
D. In addition to elevation and flood-proofing requirements for structures described herein, all floodplain management permits for new public utilities (such as pump stations, power plants, and communications) should assure that the flood damageable facility is elevated 1.5 feet above the base flood elevation or certified flood-proof. Utilities deemed critical to emergency management (including sewer, gas, electrical, and water systems) should be protected from damage in the 200-year flood event (in accordance with the Central Valley Flood Protection Board Urban Level of Flood Protection requirements).
E. Provide a drainage system report in accordance with the County Improvement Standards with a narrative describing the existing and proposed stormwater management system, including all

discharge points, collection, conveyance, and stormwater storage facilities.

F. Provide a drainage system map including, but not limited to, sub-watershed boundaries and the property's location within the larger watershed, pre development and post-development terrain at 1-foot contour intervals, and the location of all existing and proposed drainage features. Include a plan of the parcel showing applicable proposed revisions to pre-development and post development surface drainage flows.
G. Before any proposed filling in a floodplain is permitted and when a detailed hydraulic model is not available, the volume that will be occupied by the permitted fill below the base flood elevation shall be compensated for and balanced by a hydraulically equivalent volume of excavation taken from below the base flood elevation. This is a general rule on creeks and channels in riverine flow, thus is not necessary on land within the island side of levees in the Delta Area, Beach Stone Lake, and very wide levee breach floodplains of the Cosumnes River floodplain.
H. No new construction or substantial improvements or development may occur without the approval of the Floodplain Administrator and without demonstrating that the cumulative effect of the proposed development when combined with all the existing and anticipated development will not have adverse impacts on downstream, upstream, or adjacent properties, and the FEMA mapping requirements of section 905-08 are met.
I. In floodplains of natural streams and natural stream tributaries, and other streams subject to review and approval by the Floodplain Administrator, grading causing an adverse impact, as measured at the property lines of the parcel(s) being developed, must be approved by the Floodplain Administrator.
J. Stormwater calculations by a professional civil engineer shall be submitted to the Floodplain Administrator, including but not limited to, detention basin sizing, storm drain pipe sizing, and overland flow path design.
K. The majority of stormwater management features in the urban services area of the County are maintained in a routine manner funded by the Storm Water Utility; however, on occasion, an operation and maintenance procedure for peculiar features will require a supplemental funding agreement.
L. The applicant shall obtain all required state and federal permits.
M. All new development within Zone A that creates more than 4 lots or involves more than 5 acres of land shall provide base flood elevation data to the Floodplain Administrator and meet FEMA

mapping requirements per section 905-08. The base flood elevation shall be determined to the satisfaction of the Floodplain Administrator.

N. Development master plan floodplain models for specific plan areas must establish the existing condition base flood elevation and assure no adverse impact in accordance with this ordinance. The project proponent shall submit the existing condition model to the Floodplain Administrator prior to publishing the environmental impact report for that development proposal. When the watershed area is greater than one square mile, the existing condition floodplain model must be submitted to FEMA for approval before improvement plans are approved for the development. The project proponent must obtain a CLOMR (Conditional Letter of Map Revision) from FEMA for any actions affecting the floodplain before those actions are constructed.
O. Development projects subject to the Urban Level of Flood Protection (ULOP) as determined through §902-57.1, must be planned and designed to achieve the Urban Level of Flood Protection developed by the State of California Department of Water Resources. The County of Sacramento must make a finding for projects subject to ULOP, per §5.11 of the Sacramento County Zoning Code. Substantial evidence, such as a study prepared by a registered engineer, must be provided to support any finding(s).