ENG-006 Improvement Plans Required Application Contents

To provide minimum site plan requirements for improvement plan permit applications. Improvement plans are plan sets that incorporate multiple Engineering disciplines to perform comprehensive plan reviews specific to discretionary projects such as subdivisions, apartment complexes, commercial centers, and industrial facilities.

Plans shall be compiled into one PDF document (24 inches by 36 inches) and shall be of sufficient clarity to indicate the nature and extent of the work proposed and demonstrate the proposed work will comply with all relevant laws, ordinances, regulations, and conditions of approval (COA).

Plans shall include all applicable items listed below. Additional information may be required by plan review staff to ensure compliance with the above paragraph.

General

1. Cover Sheet

   1. Name of project
   2. Address
   3. Assessor’s Parcel Number(s)
   4. Road name, road number and post mile range
   5. Vicinity and location map
   6. Planning and at-cost file numbers
   7. Purpose statement
   8. Earthwork quantities in cubic yards (cut & fill table)
   9. Amount of disturbed area in acres
   10. Amount of new/replaced impervious surface, in square feet
   11. Title Block
   12. Seal and signature of licensed professional
   13. Appropriate County signature block(s)
       1. Chief Building Official of Permit Sonoma– for private subdivision roads
       2. Sonoma Public Infrastructure (SPI) Director – for public improvements or as required by COA
       3. Sonoma Water Director of Engineering – for public sewer mains
   14. Date plans prepared
   15. Sheet number and number of sheets
   16. Property owner name and contact information
   17. Plan preparer name and contact information
   18. Reference datum and benchmarks
   19. Space for approval stamps in lower right corner
   20. Symbols and abbreviations legend

2. Plan Sheets

   1. County required standard notes
      • GRD-009 Grading and Drainage Inspection Notes
      • GRD-010 Grading and Drainage Notes
      • GRD-011 Erosion Prevention and Sediment Control Notes
   2. Conditions of Approval (COA)
   3. Drawn to an engineering scale no less than 1 inch = 40 feet 
   4. North arrow and scale (written and graphic)
   5. Property lines identified on all pertinent views and details
   6. Assessor's Parcel Numbers for adjacent lands
   7. Right-of-ways identified on all pertinent views and details
   8. Easements shown with reference to document number (existing, proposed, public & private) identified on all pertinent views and details
   9. Project boundaries; show existing and proposed development
   10. Contours and elevations identified as existing or proposed
   11. Special flood hazards and geological hazard areas delineated
   12. Wetlands and/or sensitive areas delineated
   13. Buildings identified as existing or proposed
   14. Finished floor elevations of all relevant buildings
   15. Well and Septic locations identified as existing and proposed (for reference only)
   16. Existing and proposed utilities (for reference only)
   17. Any applicable setback requirements

3. Fire Safety Measures, Turnaround, Turnouts, Hydrants, Bollards, Etc.

   Note: Refer to the Fire Prevention and Hazardous Materials Division for more information about this review process.

4. Accessible Paths of Travel for Commercial Projects

   Note: Refer to the Building Division for more information about this review process.

Grading

5. Grading Plan

   1. Limits of grading work clearly delineated
   2. Dimensions to property lines and buildings
   3. Grades of proposed slopes
   4. Cross-sections of proposed building pads
   5. Cross-sections of cuts and fills
   6. Areas requiring keying and benching delineated including a reference detail
   7. Details and recommendations from soils report
   8. Terrace standards met

Drainage

6. Drainage Plan

   1. Drainage features identified as existing and proposed
   2. Subdrains identified as existing and proposed
   3. Elevation of inverts, flowlines, top- of- grates, high points, etc.
   4. Drainage specifications including, but not limited to size, material, length, and slope
   5. Structure list for large networks
   6. Cross-sections of existing waterways for proposed work in or near waterways
   7. NPDES MS4 permit provisions met
   8. Details and recommendations from drainage report

Roads, Driveways and Right of Way Improvements

7. Notes

   1. SPI Standard Improvement Plan Construction Notes 199 A-H
   2. SPI Street Lighting Requirement Notes & Legend 699 A & B
   3. SPI Signing, Striping, and Markings Specifications 799 A & B

8. Plans

   1. Road names, existing and proposed
   2. Property lines and rights-of-way, existing and proposed
   3. Centerline stationing (construction alignment) for begin and end of curves, grade- breaks, driveways, and monuments
   4. Horizontal curve data
   5. Top-of-curb (T) stationing, elevations, and grade- breaks
   6. Gutter slopes and flow arrows
   7. Sidewalks
   8. SPI construction standard details
   9. Signing and Striping Plan
   10. Lighting Plan
   11. Traffic Control Plan

9. Roads and Driveways (General)

   1. Cross Sections (minimum every 50 feet)
   2. Road width, curb, and sidewalk (call out details as necessary)
   3. Crown and centerline
   4. Pavement and base: type, thickness, resistance (R) and traffic index (T I ) used
   5. Cross Slope
   6. Cut and fill limits, right-of-way
   7. Road/Driveway typical structural section detail

10. Profile

    1. Existing and finish ground
    2. Stationing and elevations at grade-breaks
    3. Vertical curve data

Sewer

11. General Items

    1. Existing and proposed sewer lines and appurtenances (clean-outs, manholes, junctions, lift stations, etc.) clearly identified
    2. Sewer line specifications including but not limited to pipe size/diameter, material, length, and slope
    3. Location of septic tank(s) to be destroyed
    4. Sonoma Water construction standard drawings
    5. Sonoma Water sewer construction and inspection notes
    6. All other pertinent sewer construction notes and details

12. Sewer Mains and Public Improvements

    1. Elevations of inverts and relative surface features
    2. Centerline stationing (construction alignment)
    3. Profiles with existing and proposed elevations for surfaces and sewer lines and appurtenance

Erosion Control

13. Erosion Prevention and Sediment Control Plan

    1. Best management practices (BMPs) locations
    2. BMP details and specifications
    3. Protective fencing for waterways and sensitive areas
    4. Limits of disturbed areas (total work) clearly delineated including but not limited to temporary features such as BMP locations, staging areas, material stockpiles, construction accesses, etc.

Water

14. Water Main Improvement Plans

    Note: Approved water main plans attached for reference only.