Nevada County Municipal Code Ch. 12 Grading

The purpose of this Section is to safeguard life, limb, property and the public welfare by regulating grading and construction activities that result in a land disturbance on private property.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. This Section sets forth rules and regulations to control excavation, grading and earthwork construction, including fills and embankments; establishes standards of required performance in preventing or minimizing water quality impacts from storm water runoff; establishes the administrative procedure for issuance of permits; and provides for approval of plans and inspection of grading construction, drainage, and erosion and sediment controls at construction sites.

Vehicular ways shall conform to the grading requirements of this Chapter.

B. The standards listed below are recognized standard:

1. Testing.

a. ASTM D 1557, Moisture-Density Relations of Soils and Soil Aggregate Mixtures.

b. ASTM D 1556, In Place Density of Soils by the Sand-Cone Method.

c. ASTM D 2167, In Place Density of Soils by the Rubber-Balloon Method.

d. ASTM D 2937, In Place Density of Soils by the Drive-Cylinder Method.

e. ASTM D 6938, In Place Moisture Contact and Density of Soils by Nuclear Methods.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. Except as specified in Subsection 3.B below of this Section, no person shall do any grading without first having obtained a grading permit from the Building Official.

1. No drainage culvert, piping, V-ditch or energy dissipater shall be installed, replaced, altered or repaired without first obtaining a permit from the Building Official.

2. No pond shall be installed, repaired or altered without first obtaining a permit from the Building Official.

Exception: Performance of emergency work necessary to protect life or property when an urgent necessity therefore arises. The person performing such emergency work shall notify the Building Official promptly of the problem and work required and shall apply for a permit therefore within ten (10) calendar days after commencing said work.

B. Except in flood plains as regulated in Section 12.04.310 of this Code, a grading permit is not required for the following, provided no unstable or erodible slopes are created and no encroachment onto sewage disposal systems, water supply systems or hazardous material sites, areas or setbacks is created. NOTE: Owners/operators of sites may still need NPDES storm water permit coverage with the State if the construction activity is part of a larger common plan of development or sale that would result in a land disturbance of greater than or equal to one (1) acre.

1. When approved by the Building Official, grading which does not exceed two hundred fifty (250) cubic yards in an isolated, self-contained area, with cuts, fills and erosion control conforming to the requirements of this Section, provided there is no danger to private or public property, it does not pose a significant erosion or sediment discharge hazard and is not intended to support a building or structure on fill.

2. An excavation below finished grade for basements and footings of a building, retaining wall or other structure authorized by a valid building permit. This shall not exempt any fill made with the material from such excavation or exempt any excavation having an unsupported height greater than five (5') feet (one thousand five hundred twenty-four (1,524) mm) after the completion of such structure.

3. Cemetery graves.

4. Refuse disposal sites controlled by other regulations.

5. Excavations for wells or tunnels or utilities.

6. Mining, quarrying, excavating, processing or stockpiling of rock, sand, gravel, aggregate or clay where established and provided for by law, provided such operations do not affect the lateral support or increase the stresses in or pressure upon any adjacent or contiguous property.

7. Exploratory excavations under the direction of soil engineers, engineering geologists, or registered environmental health specialists limited to sewage disposal systems. Such work shall be backfilled and shaped to the original contour of the land after the investigation.

8. An excavation that is less than two (2') feet (six hundred ten (610) mm) in depth, does not create a cut slope greater than five (5') feet (one thousand five hundred twenty-four (1,524) mm) in height and steeper than one (1) unit vertical in one and one-half (1.5) units horizontal (sixty-six and seven tenths percent (66.7%) slope) and does not exceed fifty (50) cubic yards.

9. A fill less than one (1') foot (three hundred five (305) mm) in depth and placed on natural terrain with a slope flatter than one (1) unit vertical in five (5) units horizontal (twenty percent (20%) slope), or less than three (3') feet (nine hundred fourteen (914) mm) in depth, not intended to support structures, that does not exceed fifty (50) cubic yards on any one (1) lot and does not obstruct a drainage course.

10. Land disturbance by plowing under or burial of less than ten thousand (10,000) square feet of vegetation on slopes ten percent (10%) or steeper or any amount of vegetation, up to one (1) acre, on slopes flatter than ten percent (10%).

11. Grading done by or under the supervision or construction control of a public agency that assumes full responsibility for the work to the extent required by this law.

12. Cultivation of land to raise crops, or other clearing and grading of land for agricultural operations pursuant to criteria enacted and codified in 14.10, Landform Grading for Agriculture, of this Title.

13. Maintenance of existing firebreaks and roads to keep the firebreak or road substantially in its original condition.

14. Timber harvest and management activities when approved and carried out consistent with the California Forest Practices Act. Activities that are not exempt from the local regulation pursuant to Cal. Pub. Res. Code § 4516.4 are subject to these regulations. Permits are required for private roads within timber harvest areas where the proposed improvements are in excess of the minimum road standards required by the California Department of Forestry for timber harvesting activities.

15. Clearing for fire protection purposes within one hundred (100) feet of a dwelling unit. Any additional clearing for fire prevention, control or suppression purposes is exempt when authorized or required in writing by a fire prevention or suppression agency.

C. The County may prepare and adopt a more comprehensive exemption for grading for agricultural operations than the existing exemption for cultivation of land to raise crops as part of 14.10 of this Title, provided that the exemption does not involve construction of any building or site preparation for any development project and that the purpose of such exemption is to promote long-term viable agricultural use of agricultural lands while protecting natural resources and provide reasonable minimum standards that define desired performance in the prevention of man-induced land failures, and control erosion, drainage, and sediment discharge.

Exemption from the permit requirements of this Chapter shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this chapter or any other laws or ordinances of this jurisdiction.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

Whenever the Building Official determines that any existing excavation or embankment or fill on private property has become a hazard to life and limb, or endangers property, or adversely affects the safety, use or stability of a public way or drainage channel, the owner of the property upon which the excavation or fill is located, or other person or agent in control of said property, upon receipt of notice in writing from the Building Official, shall within the period specified therein repair or eliminate such excavation or embankment to eliminate the hazard and to be in conformance with the requirements of this Code.

Adequate protection from hazards shall be provided at excavations. All pits, shafts, etc. shall be barricaded or covered. Upon completion of exploratory excavations and other similar operations, temporary trenches, wells, pits, shafts, etc. shall be backfilled.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. For the purpose of this Section, the definitions listed hereunder shall be construed as specified in this Section.

1. Agricultural Operation for grading purposes is any land-related activity for the purpose of cultivating or raising plants or animals or conserving or protecting lands for such purpose and is not surface mining or borrow pit operations.

2. American Society for Testing and Materials (ASTM) is a membership society that is the foremost United States source of information on the specifications and testing of materials.

3. Approval shall mean that the proposed work or completed work conforms to this chapter in the opinion of the Building Official.

4. As-Graded is the extent of surface conditions on completion of grading.

5. Bedrock is in-place solid rock.

6. Bench is a relatively level step excavated into earth material on which fill is to be placed.

7. Borrow is earth material acquired from an off-site location for use in grading on a site.

8. Best Management Practices (BMPs) are physical and managerial practices that, when used separately, or in combination, prevent or reduce erosion, sedimentation, or pollution of water. An example of a guide for BMPs is the State Water Resources Control Board Best Management Practices Construction Handbook.

9. Certified Professional in Erosion and Sediment Control (CPESC) is a recognized specialist in soil erosion and sediment control.

10. Civil Engineer is a professional engineer registered in the state to practice in the field of civil works.

11. Civil Engineering is the application of the knowledge of the forces of nature, principles of mechanics and the properties of materials to the evaluation, design and construction of civil works.

12. Clearing is the destruction or removal of vegetative surface cover by manual, mechanical, or chemical methods resulting in exposed soils that may be subject to erosion. This does not include clearing techniques that retain vegetation and natural drainage patterns.

13. Compaction is the densification of a fill by mechanical means.

14. Construction Activities include, but are not limited to: Clearing, grading, demolition, excavation, construction of new structures, and reconstruction of existing facilities involving removal and replacement that results in soil disturbance. This includes construction access roads, staging areas, storage areas, stockpiles, and any off-site areas that receive run-off from the construction project such as discharge points into a receiving water. Construction activity does not include routine maintenance to maintain original line and grade, hydraulic capacity, or original purpose of the facility.

15. Cut. See Excavation.

16. Depth of Fill is the vertical dimension from the exposed fill surface to the original ground surface.

17. Depth Of Excavation (CUT) is the vertical dimension from the exposed cut surface to the original ground surface.

18. Earth Material is any rock, natural soil or fill or any combination thereof.

19. Embankment. See Fill.

20. Engineering Geologist is a geologist experienced and knowledgeable in engineering geology.

21. Engineering Geology is the application of geologic knowledge and principles in the investigation and evaluation of naturally occurring rock and soil for use in the design of civil works.

22. Engineered Grading Plan is a plan prepared by registered design professional authorized to do so by the State of California, describing the vertical and horizontal alignment and/or arrangement of grading.

23. Erosion is the wearing away of the ground surface as a result of the movement of wind, water or ice.

24. Excavation is the mechanical removal of earth material.

25. Expansive Soil is any soil which exhibits expansive properties in excess of index rating of twenty (20) as determined by the procedures defined in the California Building Code.

26. Fill is a deposit of earth material placed by artificial means.

27. Geologic Hazard is any condition in naturally occurring earth materials which may endanger life, health or property.

28. Geotechnical Engineer. See "Soils engineer."

29. Grade is the vertical location of the ground surface.

30. Grading Plan. See engineered grading plan.

31. Existing Grade is the grade prior to grading.

32. Finish Grade is the final grade of the site that conforms to the approved plan.

33. Rough Grade is the stage at which the grade approximately conforms to the approved plan.

34. Grading is any excavating or filling or combination thereof.

35. Grading Work is grading and related work such as, but not limited to, drainage improvements and erosion and sediment control.

36. Key is a designed compacted fill placed in a trench excavated in earth material beneath the toe of a proposed fill slope.

37. Land Disturbance is any activity that results in a change in the soil cover or the soil topography that may result in soil erosion from water or wind and the movement of sediments off site, including, but not limited to, clearing, grading, excavating, transporting, and filling of land.

38. Professional Inspection is the inspection required by this Code to be performed by the civil engineer, soils engineer or engineering geologist. Such inspections include that performed by persons supervised by such engineers or geologists and shall be sufficient to form an opinion relating to the conduct of the work.

39. Rainy Season is the period of the year during which there is a substantial risk of rainfall. For the purpose of this Chapter, the rainy season is defined as from October 15th to April 15th, inclusive.

40. Registered Environmental Health Specialist (REHS) is an environmental health professional educated and trained within the field of environmental health who is registered with the State.

41. Sediment is any material transported or deposited by water, including soil debris or other foreign matter.

42. Site is any lot or parcel of land or contiguous combination thereof, under the same ownership, where grading is performed or permitted.

43. Slope is an inclined ground surface the inclination of which is expressed as a ratio of horizontal distance to vertical distance.

44. Slope, Determination Of means the cross-slope of a parcel by measurement, at established intervals not crossing defined grade breaks, of the average slope perpendicular to the contour lines.

45. Soil is naturally occurring superficial deposits overlying bedrock.

46. Soils Engineer (Geotechnical Engineer) is an engineer experienced and knowledgeable in the practice of soils engineering (geotechnical) engineering.

47. Soils Engineering (Geotechnical Engineering) is the application of the principles of soils mechanics in the investigation, evaluation and design of civil works involving the use of earth materials and the inspection or testing of the construction thereof.

48. Storm Water Pollution Prevention Plan (SWPPP) is a plan required for various construction and industrial activities pursuant to the Federal Clean Water Act and related State regulations.

49. Terrace is a relatively level step constructed in the face of a graded slope surface for drainage and maintenance purposes.

50. Vehicular Way is any public or private roadway or driveway designed for or used by vehicles (as defined by the California Vehicle Code).

51. Watercourse is any natural or manmade channel flowing continuously or intermittently in a definite direction and course or used for the holding, delay or storage of waters, which functions at any time to convey or store storm water runoff. Natural channels shall generally be limited to those designated by a solid line or a dash and three (3) dots as shown in blue on the most recent U.S. Geological Survey 7.5-minute series of topographic maps. At the discretion of the Building Official, the definition of natural Channel may be limited to those channels having a watershed area of fifty (50) acres or more, and this definition will be commonly used in connection with the administration of this Chapter except for those cases in which the Building Official determines that the definition must be extended to a natural channel with a watershed smaller than fifty (50) acres in order to prevent a condition which is a menace to life and limb, endangers property, is a hazard to public safety, adversely affects the safety, use or serviceability of adjacent property, public way or drainage channel, or could adversely affect the water quality of any water bodies or watercourses were the definition not extended to a particular natural channel with a watershed below fifty (50) acres.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. Except as exempted in Section 14.12.030 of this Code, no person shall do any grading without first obtaining a grading permit from the Building Official. A separate permit shall be obtained for each site and may cover both excavations and fills.

1. No person shall do or permit to be done any grading in such a manner that quantities of dirt, soil, rock, debris, or other material substantially in excess of natural levels are washed, eroded, or otherwise moved from the site, except as specifically provided for by a permit.

2. No person shall do or permit to be done any grading which may obstruct, impede or interfere with the natural flow of storm waters, whether such waters are unconfined upon the surface of the land or confined within land depressions or natural drainage ways, unimproved channels or watercourses, or improved ditches, channels or conduits, in such manner as to cause flooding where it would not otherwise occur, aggravate any existing flooding condition or cause accelerated erosion except where said grading is in accordance with all applicable laws, including but not limited to, these permit requirements.

Dam construction of "Jurisdictional Size" are regulated and permitted by the Department of Water Resources, Division of Dam Safety. Dam construction of "Non-Jurisdictional Size" are regulated and permitted by the Building Department" (See Figure A).

Figure A [Figure: Figure A]

The construction of dams and reservoirs in excess of five (5') feet in height but twenty-five (25') feet or less in height from the natural bed of the stream or watercourse at the downstream toe of the barrier, regardless of storage capacity, or which have a storage capacity in excess of fifteen (15') acre feet but less than fifty (50') acre feet, regardless of height, shall be subject to County regulatory jurisdiction administered by the Building Department as part of this Chapter. Construction of all dams and reservoirs shall follow the current practices of the Department of Water Resources, Division of Safety of Dams, as dictated in the publication, "Guidelines for the Design and Construction of Small Embankment Dams" (with the exception of contact agency and application process).

3. Pond Construction and design shall be done in conformance with the most recent Conservation Practice Standard, "Pond" (Code 378) as published by the Natural Resources Conservation Service.

B. The provisions of Section 105, Chapter 1, Division II, are applicable to grading. Additionally, the application shall state the estimated quantities of work involved.

C. Grading shall be performed in accordance with the approved grading plan prepared by registered design professional, and shall be designated "engineered grading" The Building Official may waive this requirement if the proposed grading is minor in nature and would not endanger the public health, safety and welfare. This grading shall be designated "regular grading."

D. Engineered Grading Requirements.

1. For engineered grading requirements applications for a grading permit shall be accompanied by three (3) set of plans and two (2) sets of specifications and supporting data. A soils/geotechnical engineering report shall be provided in accordance with the California Building Code.

a. When the proposed grading includes a cut or fill exceeding ten (10') feet in-depth at any point, or a cut or fill exceeding seven (7') feet in depth at any point with the slope of the natural ground exceeding twenty percent (20%);

b. When highly expansive soils are present; or

c. In areas of known or suspected geological hazards, including landslide hazards and hazards of ground failure stemming from seismically induced ground shaking.

An engineering geology report shall be included with the supporting data when the proposed grading is in excess of five thousand (5,000) cubic yards. (See Section 14.12.060(F))

Specifications shall contain information covering construction and material requirements.

Plans shall be drawn to scale and shall be of sufficient clarity to indicate the nature and extent of the work proposed and show in detail that they will conform to the provisions of this Code and all relevant laws, ordinances, rules and regulations. The first sheet of each set of plans shall give location of the work, the name and address of the owner, and the person by whom they were prepared.

2. The plans shall include the following information:

a. General vicinity of the proposed site.

b. Property limits and accurate contours of existing ground and details of terrain and area drainage.

c. Limiting dimensions, elevations or finish contours to be achieved by the grading, and proposed drainage channels and related construction.

d. Detailed plans of all surface and subsurface drainage devices, walls, cribbing, dams and other protective devices to be constructed with, or as a part of, the proposed work, together with a map showing the drainage area and the estimated runoff of the area served by any drains.

e. Location of any buildings or structures on the property where the work is to be performed and the location of any buildings or structures on land of adjacent owners that are within fifteen (15') feet (four thousand five hundred seventy-two (4,572) mm) of the property or that may be affected by the proposed grading operations.

f. Recommendations included in the soils engineering report and the engineering geology report shall be incorporated in the grading plans or specifications. When approved by the Building Official, specific recommendations contained in the soils engineering report and the engineering geology report, which are applicable to grading, may be included by reference.

g. The dates of the soils engineering and engineering geology reports together with the names, addresses and phone numbers of the firms or individuals who prepared the reports.

h. Cross sections (not less than two (2)) of existing and proposed graded areas taken at intervals not exceeding two hundred (200) feet and at locations of maximum cuts and fills.

i. An estimate of the quantities of excavation and fill, including quantities to be moved both on and off site.

j. A detailed erosion and sediment control plan including specific locations, construction details and supporting calculations for temporary and permanent sediment control structures and facilities.

k. A landscaping plan, including temporary erosion control plantings, permanent drought-resistant slope plantings, replacement or temporary groundcover, and irrigation facilities.

l. The location of any borrow site or location for disposal of surplus material.

E. The soils engineering report required by Subsection 13.12.060.6.D shall include:

1. An index map showing the regional setting of the site;

2. A site map that shows the topographic features of the site and locations of all soil borings and test excavations accompanied with a log for each soil boring and test excavation;

3. Classification of the soil types and data regarding the nature, distribution and strength of existing soils;

4. A suitable scaled map and cross sections showing all identified areas of land slippage;

5. A description of any encountered groundwater or excessive moisture conditions;

6. Conclusions and recommendations for grading procedures and design criteria for corrective measures, including buttress fills, when necessary;

7. Opinion on adequacy for the intended use of sites to be developed by the proposed grading as affected by soils engineering factors, including the stability of slopes.

F. The engineering geology report required by Subsection 14.12.060.6.D shall include:

1. An adequate description of the geology of the site and geology of the adjacent areas when pertinent to the site;

2. Conclusions and recommendations regarding the effect of geologic conditions on the proposed development;

3. Opinion on the adequacy for the intended use of sites to be developed by the proposed grading, as affected by geologic factors; and

4. Recommendations for mitigation of geologic hazards.

G. The Building Official may require a geotechnical investigation in accordance with the California Building or Residential Code when, during the course of an investigation, any of the following conditions are discovered, the report shall address the potential for liquefaction:

1. Shallow ground water, fifty (50') feet (fifteen thousand two hundred forty (15,240) mm) or less;

2. Unconsolidated sandy alluvium;

3. Seismic Design Category C, D, E or F.

H. Regular Grading Requirements.

1. Each application for a grading permit shall be accompanied by a plan in sufficient clarity to indicate the nature and extent of the work. The plans shall give the location of the work, the name of the owner and the name of the person who prepared the plan. The plan shall include the following information:

a. General vicinity of the proposed site;

b. Limiting dimensions and depth of cut and fill;

c. Location of any buildings or structures where work is to be performed, and the location of any buildings or structures with fifteen (15') feet (four thousand five hundred seventy-two (4,572) mm) of the proposed grading;

d. Property limits and accurate contours of existing ground;

e. Typical cross section(s) of the existing and proposed graded area(s) at locations of maximum cut and fill;

f. An estimate of the quantities of excavation and fill, including quantities to be moved both on and off site.

I. The provisions of those applicable sections of Division II of the California Building Code are applicable to grading permits. The Building Official may require that grading operations and project designs be modified if delays occur which incur weather-generated problems not considered at the time the permit was issued.

J. The Building Official may require professional inspection and testing. When the Building Official has cause to believe that geologic factors may be involved, the grading will be required to conform to engineered grading.

K. In issuing a permit, the Building Official may impose conditions as prescribed by this Chapter necessary to protect the health, safety and welfare of the public, to prevent the creation of a hazard to public or private property, and to assure proper completion of the grading, including, but not limited to:

1. Mitigation of adverse environmental impacts as disclosed by any environmental document findings;

2. Improvement of any existing unstable grading affected by this permit to comply with the standards of this Section;

3. Protection of grading which would otherwise be hazardous;

4. Dust, erosion and sediment control, and season of work, weather conditions, sequence of work, access roads and haul routes;

5. Safeguard watercourses from excessive deposition of sediment or debris;

6. Safeguard areas reserved for on-site sewage disposal, water supply and hazardous material storage;

7. Assurance that the land area in which grading is proposed and for which habitable structures are proposed is not subject to hazards of land slippage or significant settlement or erosion;

8. Compliance with all applicable provisions of the Nevada County Codes.

L. If grading operations are commenced before first securing a proper permit, no permit will be issued until illegal grading has stopped. In the event that no grading permit, erosion control permit or land use permit can be issued for such operation, the site shall be restored to its original condition to the extent feasible, and to the extent full restoration is not possible mitigation measures may be imposed to remediate any damage caused. Restoration shall be in conformity to an approved restoration plan.

M. Winter operations shall not be allowed if an immitigable high potential for accelerated erosion exists due to slope, rock or soil type, proximity to a stream or drainage course, magnitude or duration of disturbance, or other characteristics of the project and the site. Approval shall be obtained from the Building Official prior to any grading activity during the rainy season.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

Permit and plan review fees shall be as set forth in the fee schedule adopted by resolution of the Nevada County Board of Supervisors.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. As a condition for the issuance of a permit, the Building Official may require the deposit of improvement security in sufficient amount deemed necessary to ensure that the work, if not completed in accordance with the approved plans and specifications, will be corrected to eliminate hazardous conditions or, in the case of a subdivision, where the permittee does not proceed with preparation and obtaining the approval of a final map. Said security shall be in the form of cash, a certified or cashier's check, a letter of credit, or a faithful performance bond executed by the applicant and a corporate surety authorized to do business in this state. The form of security shall be acceptable to County Counsel. Public agencies are exempted from this provision by law.

B. In the case of subdivisions, the improvement security shall remain in effect until final inspections have been made and the Building Official has accepted all grading work and subdivision improvements as being complete or until the subdivider has entered into an agreement to complete all unfinished work and improvements and furnished improvement security pursuant to Section 14.12.080, whichever first occurs.

C. For projects other than subdivisions, the improvements security shall remain in effect until final inspections have been made and the Building Official has accepted all grading work as being complete.

D. In addition to the improvement security, the Building Official may also require the deposit of maintenance security in a sufficient amount deemed necessary by them to guarantee and maintain the grading work to assure the proper functioning of drainage systems and adequate erosion and sedimentation control. Said maintenance security shall be in the form of cash, a certified or cashier's check, a letter of credit, or a faithful performance bond executed by the applicant and a corporate surety authorized to do business in this state and shall remain in effect for a period of one (1) year after the date of expiration of the improvement security as designated in Subsections B and C above.

E. Any bond or deposit required by the Building Official pursuant to this Section shall be payable to the Nevada County Building Department.

F. Upon satisfaction of applicable provisions of this Section, the improvement and maintenance security deposits or bonds will be released. However, upon failure to complete the work, failure to comply with all of the terms of the permit, or failure of the completed site to function properly to provide proper drainage or erosion and sedimentation control, the County may do the required work, or cause it to be done, and collect from the permittee or surety all costs incurred thereto, including administrative and inspection costs. Any unused portion of a deposit or bond shall be refunded to the permittee after deduction by the County of the cost of the work.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. Unless otherwise recommended in the approved soils engineering or engineering geology report, cuts shall conform to the provisions of this Section.

In the absence of an approved soils engineering report, these provisions may be waived for minor cuts not intended to support structures.

B. The slope of cut surfaces shall be no steeper than is safe for the intended use and shall be no steeper than one (1) unit vertical in two (2) units horizontal (fifty percent (50%) slope) unless the permittee furnishes a soils engineering or an engineering geology report, or both, stating that the site has been investigated and giving an opinion that a cut at a steeper slope will be stable and not create a hazard to public or private property.

Exception: A cut surface may be at a slope gradient of one and one-half (1.5) horizontal to one (1) vertical (sixty-seven percent (67%)) provided that all of the following are met:

1. It is not intended to support structures or surcharges.

2. It is adequately protected against erosion.

3. It is no more than eight (8') feet in height.

4. The soil is not classified as CH, CL, or MH.

5. It is approved by the Building Official.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. Unless otherwise recommended in an approved soils engineering report, fills shall conform to the provisions of this Section.

B. Where fill is intended to support any permanent structure, an engineered grading plan shall be required. The placement and compaction requirements shall be as stated in the engineering report.

1. Where fill is intended to support any paved surface, or is part of a fire access road or driveway, the requirements of this Section shall be followed.

2. The guidelines of this Section shall be followed for all other fills except compaction to a minimum of ninety percent (90%) of maximum density need not be provided for minor fills not intended as a buildable area. Lots with non-engineered fills or fills not compacted in compliance with Subsection 14.12.100.D shall be documented. Future development on the lots shall require a qualified person to determine the proposed work is not within the fill area or can adequately be built in the fill area.

C. Fill slopes shall not be constructed on natural slopes steeper than one (1) unit vertical in two (2) units horizontal (fifty percent (50%) slope). The ground surface shall be prepared to receive fill by removing vegetation, non-complying fill, topsoil and other unsuitable materials scarifying to provide a bond with the new fill and, where slopes are steeper than one (1) unit vertical in five (5) units horizontal (twenty percent (20%) slope) and the height is greater than five (5') feet (one thousand five hundred twenty-four (1,524) mm), by benching into sound bedrock or other competent material as determined by the soils engineer. The bench under the toe of a fill on a slope steeper than one (1) unit vertical in five (5) units horizontal (twenty percent (20%) slope) shall be at least ten (10') feet (three thousand forty-eight (3,048) mm) wide. The area beyond the toe of fill shall be sloped for sheet overflow or a paved drain shall be provided. When fill is to be placed over a cut, the bench under the toe of fill shall be at least ten (10') feet (three thousand forty-eight (3,048) mm) wide but the cut shall be made before placing the fill and acceptance by the soils engineer or engineering geologist or both as a suitable foundation for fill.

D. Detrimental amounts of organic material shall not be permitted in fills. Except as permitted by the Building Official, no rock or similar irreducible material with a maximum dimension greater than twelve (12") inches (three hundred five (305) mm) shall be buried or placed in fills.

Exception: The Building Official may permit placement of larger rock when the soils engineer properly devises a method of placement, and continuously inspects its placement and approves the fill stability. The following conditions shall also apply:

E. Prior to issuance of the grading permit, potential rock disposal areas shall be delineated on the grading plan;

1. Rock sizes greater than twelve (12") inches (three hundred five (305) mm) in maximum dimension shall be ten (10") feet (three thousand forty-eight (3,048) mm) or more below grade, measured vertically;

2. Rocks shall be placed so as to assure filling of all voids with well-graded soil.

F. All fills shall be compacted to a minimum of ninety percent (90%) of maximum density.

G. The slope of fill surfaces shall be no steeper than is safe for the intended use. Fill slopes shall be no steeper than one (1) unit vertical in two (2) units horizontal (fifty percent (50%) slope).

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. Cut and fill slopes shall be set back from site boundaries in accordance with this Section. Setback dimensions shall be horizontal distances measured perpendicular to the site boundary. Setback dimensions shall be as shown in Figure A-33-1.

[Figure]

B. The top of cut slopes shall not be made nearer to a site boundary line than one-fifth (⅕) of the vertical height of cut with a minimum of two (2') feet (six hundred ten (610) mm) and a maximum of ten (10') feet (three thousand forty-eight (3,048) mm). The setback may need to be increased for any required interceptor drains.

C. The toe of fill slope shall be made not nearer to the site boundary line than one-fifth (⅕) the height of the slope with a minimum of two (2') feet (six hundred ten (610) mm) and a maximum of twenty (20') feet (six thousand ninety-six (6,096) mm). Where a fill slope is to be located near the site boundary and the adjacent off-site property is developed, special precautions shall be incorporated in the work as the Building Official deems necessary to protect the adjoining property from damage as a result of such grading. These precautions may include, but are not limited to:

1. Additional setbacks;

2. Provision for retaining or slough walls;

3. Mechanical or chemical treatment of the fill slope surface to minimize erosion;

4. Provisions for the control of surface waters.

D. The Building Official may approve alternate setbacks. The Building Official may require an investigation and recommendation by a qualified engineer or engineering geologist to demonstrate that the intent of this Section has been satisfied.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. Unless otherwise recommended by a registered design professional, drainage facilities and terracing shall be provided in accordance with the requirements of this Section.

Exception: Drainage facilities and terracing need not be provided where the ground slope is not steeper than three (3) horizontal to one (1) vertical (thirty-three percent (33%)).

All areas shall be graded and drained so that water will not pond or accumulate. Drainage shall be effected in such a manner that it will not cause erosion or endanger the stability of any cut or fill slope or any building or structure.

Storm drainage and design standards not otherwise specified herein shall comply with Section 16.12.010 the County of Nevada Code.

B. Terraces at least six (6') feet (one thousand eight hundred twenty-nine (1,829) mm) in width shall be established at not more than thirty (30')-foot (nine thousand one hundred forty-four (9,144) mm) vertical intervals on all cut or fill slopes to control surface drainage and debris except that where only one (1) terrace is required, it shall be at mid-height. For cut or fill slopes greater than sixty (60') feet (eighteen thousand two hundred eighty-eight (18,288) mm) and up to one hundred twenty (120) feet (thirty-six thousand five hundred seventy-six (36,576) mm) in vertical height, one (1) terrace at approximately mid-height shall be twelve (12') feet (three thousand six hundred fifty-eight (3,658) mm) in width. Terrace widths and spacing for cut and fill slopes greater than one hundred twenty (120') feet (thirty-six thousand five hundred seventy-six (36,576) mm) in height shall be designed by the civil engineer and approved by the Building Official. Suitable access shall be provided to permit proper cleaning and maintenance.

Swales or ditches on terraces shall have a minimum gradient of five percent (5%) and must be paved with reinforced concrete not less than three (3") inches (seventy-six (76) mm) in thickness or an approved equal paving. They shall have a minimum depth at the deepest point of one (1) foot (three hundred five (305) mm) and a minimum paved width of five (5') feet (one thousand five hundred twenty-four (1,524) mm).

A single run of swale or ditch shall not collect runoff from a tributary area exceeding thirteen thousand five hundred (13,500) square feet (one thousand two hundred fifty-four and two tenths (1254.2) m 2 ) (projected) without discharging into a down drain.

C. Cut and fill slopes shall be provided with subsurface drainage as necessary for stability.

D. All drainage facilities shall be designed to carry waters to the nearest practicable drainage way approved by the Building Official or other appropriate jurisdiction as a safe place to deposit such waters. Erosion of ground in the area of discharge shall be prevented by installation of non-erosive down-drains or other devices.

Building pads shall have a drainage gradient of five percent (5%) toward approved drainage facilities, unless waived by the Building Official.

Exception: The gradient from the building pad may be two percent (2%) if all of the following conditions exist throughout the permit area:

E. No proposed fills are greater than ten (10') feet (three thousand forty-eight (3,048) mm) in maximum depth.

1. No proposed finish cut or fill slope faces have a vertical height in excess of ten (10') feet (three thousand forty-eight (3,048) mm).

2. No existing slope faces steeper than one (1) unit vertical in ten (10) units horizontal (ten percent (10%) slope) have a vertical height in excess of ten (10) feet (three thousand forty-eight (3,048) mm).

When surface drainage is discharged onto any property, it shall be discharged in such a manner that it will not cause erosion or endanger any cut or fill slope or any building or structure. A grading and discharge plan shall be required which includes the analysis of the effect of the discharge.

F. Paved interceptor drains shall be installed along the top of all cut slopes where the tributary drainage area above slopes toward the cut and has a drainage path greater than forty (40') feet (twelve thousand one hundred ninety-two (12,192) mm) measured horizontally. Interceptor drains shall be paved with a minimum of three (3") inches (seventy-six (76) mm) of concrete or gunite and reinforced. They shall have a minimum depth of twelve (12") inches (three hundred five (305) mm) and a minimum paved width of thirty (30") inches (seven hundred sixty-two (762) mm) measured horizontally across the drain. The slope of drain shall be approved by the Building Official.

G. Drainage across property lines shall not exceed that which existed prior to grading. Excess or concentrated drainage shall be contained on site or directed to an approved drainage facility. Erosion of the ground in the area of discharge shall be prevented by installation of non-erosive down drains and other devices.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. The construction and design of all roadways shall be done in conformance with Section 12.04.310 under this Code.

B. The construction and design of all driveways shall be done in conformance with Chapter 4.03 of this Code.

1. At no place along the length of a driveway shall the grade be in excess of the established grades in Chapter 4.03.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. The following shall apply to the control of erosion and sediment from grading and construction activities resulting in land disturbance:

1. Plans shall be designed with long-term erosion and sediment control as a primary consideration;

2. Grading and construction activities during the rainy season shall provide erosion and sediment control measures except upon a clear demonstration to the satisfaction of the Building Official that at no stage of the work will there be any substantial risk of increased sediment discharge from the site;

3. Should land disturbance be permitted during the rainy season, the smallest practicable area of erodible land shall be exposed at any one time during grading operations and the time of exposure shall be minimized;

4. Natural features, including vegetation, terrain, watercourses and similar resources shall be preserved wherever possible. Limits of land disturbance shall be clearly defined and marked to prevent damage by construction equipment;

5. Permanent drought-resistant vegetation and structures for erosion and sediment control shall be installed as soon as possible;

6. Provision shall be made for long-term maintenance of permanent erosion and sediment control structures and vegetation;

7. No topsoil shall be removed from the site unless otherwise directed or approved by the Building Official. Topsoil overburden shall be stockpiled and redistributed within the graded area after rough grading to provide a suitable base for seeding and planting. Runoff from the stockpiled area shall be controlled to prevent erosion and resultant sedimentation of receiving water;

8. Runoff shall not be discharged from the site in quantities or at velocities substantially above those that occurred before land disturbance, or channeled, concentrated or redirected except into drainage facilities whose design has been specifically approved by the Building Official;

9. The permittee shall take reasonable precautions to ensure that vehicles do not track or spill earth materials into public streets and shall immediately remove such materials if this occurs.

B. Should increase sediment discharge occur or become imminent, the permittee shall take all necessary steps to control such discharge. Such steps may include construction of additional facilities or removal, or alteration of facilities required by approved erosion and sediment control plans. Facilities removed or altered shall be restored as soon as possible afterward or appropriate changes in the plan shall be immediately requested pursuant to this Chapter. Permittee shall take prompt action to resolve emergency problems; otherwise, the Building Official may take such actions as required to abate a hazardous public nuisance.

C. Erosion and sediment control plans prepared pursuant to this Chapter shall comply with all of the following:

1. The erosion and sediment control plan need not be a separate sheet if all facilities and measures can be shown on the grading sheets without obscuring the clarity of either the grading plan or the erosion and sediment control plan.

2. An erosion and sediment control plan shall be required for any grading project required to have a grading permit.

Exception: The Building Official determines that the grading and/or construction activity will not impose a significant erosion or sediment discharge hazard.

3. Erosion and sediment control plans shall include an effective re-vegetation program to stabilize all disturbed areas that will not be otherwise protected. All such areas where construction activities have been completed between April 15th and October 15th shall be planted no later than November 1st. Land disturbance areas completed at other times of the year shall be planted within fifteen (15) days. If re-vegetation is infeasible or cannot be expected to stabilize an erodible area with assurance during any part of the rainy season and the unstable area exceeds two thousand five hundred (2,500) square feet, additional erosion and sediment control measures or irrigation of planted slopes may be required as appropriate to prevent increased sediment discharge.

4. Erosion and sediment control plans shall be designed to prevent increased discharge of sediment at all stages of grading and construction activities from initial disturbance of the ground to project completion. Every feasible effort shall be made to ensure that site stabilization is permanent. Plans shall indicate the implementation period and the stage of construction where applicable.

5. Erosion and sediment control plans shall comply with the recommendations of any Civil Engineer, Geotechnical Engineer, Engineering Geologist, Architect, or Soil Erosion Control Specialist involved in preparation of the grading plans.

6. The structural and hydraulic adequacy of all storm water containment or conveyance facilities shown on the erosion and sediment control plans shall be verified by a Civil Engineer, and he shall so attest on the plans. Sufficient calculations and supporting material to demonstrate such adequacy shall accompany the plans when submitted.

7. Erosion and sediment control plans shall be designed to meet anticipated field conditions.

8. Erosion and sediment control plans shall provide for inspection and repair of all erosion and sediment control facilities at the close of each working day during the rainy season, and for specific sediment clean-out and vegetation maintenance criteria.

9. Erosion and sediment control plans shall comply with any and all standards and specifications adopted herein for the control of erosion and sedimentation on grading sites. These standards and specifications shall be in general compliance with the Erosion and Sediment Control Guidelines for Developing Areas of the Sierras published by High Sierra Resource Conservation and Development Council.

10. For projects subject to the State requirements to prepare a SWPPP (Storm Water Pollution Prevention Program) a preliminary SWPPP may be submitted in lieu of the erosion and sediment control plan required by these regulations.

11. Erosion control measures shall be installed in accordance with the issued grading and/or construction plans prior to any rain event. Any grading completed between October 15th and April 15th shall have all erosion control materials that are required be installed in accordance with the issued construction and grading plans onsite.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. Grading operations for which a permit is required shall be subject to inspection by the Building Official. Professional inspection of grading operations shall be provided by the civil engineer, soils engineer, and the engineering geologist retained to provide such services in accordance with Subsection E herein for engineered grading and as required by the Building Official for regular grading.

B. The civil engineer shall provide professional inspection within such engineer's area of technical specialty, which shall consist of observation and review as to the establishment of line, grade and surface drainage of the development area. If revised plans are required during the course of the work, they shall be prepared by the civil engineer.

C. The soils engineer shall provide professional inspection within such engineer's area of technical specialty, which shall include observation during grading and testing for required compaction. The soils engineer shall provide sufficient observation during the preparation of the natural ground and placement and compaction of the fill to verify that such work is being performed in accordance with the conditions of the approved plan and the appropriate requirements of this Chapter. Revised recommendations relating to conditions differing from the approved soils engineering and engineering geology reports shall be submitted to the permittee, the Building Official and the civil engineer.

D. The engineering geologist shall provide professional inspection within such engineer's area of technical specialty, which shall include professional inspection of the bedrock excavation to determine if conditions encountered are in conformance with the approved report. Revised recommendations relating to conditions differing from the approved engineering geology report shall be submitted to the soils engineer.

E. The permittee shall be responsible for the work to be performed in accordance with the approved plans and specifications and in conformance with the provisions of this Code, and the permittee shall engage consultants, if required, to provide professional inspections on a timely basis. The permittee shall act as a coordinator between the consultants, the contractor and the Building Official. In the event of changed conditions, the permittee shall be responsible for informing the Building Official of such change and shall provide revised plans for approval.

Periodic progress reports may be required to be rendered by the permittee at commencement and completion of major key grading and erosion and sediment control operations.

No permittee shall be deemed to have complied with this Section until the Building Official has made a final inspection of the work and has certified in writing that the work has been completed in accordance with all requirements and conditions of the permit.

The permittee shall provide adequate access to the site for inspection by the Building Official during the performance of all work and for a minimum period of one (1) year after acceptance by the Building Official of all improvements pursuant to this Section.

F. The Building Official shall inspect the project at the various stages of work requiring approval to determine that adequate control is being exercised by the professional consultants.

G. If, in the course of fulfilling their respective duties under this Section, the civil engineer, the soils engineer, or the engineering geologist finds that the work is not being done in conformance with this Chapter or the approved grading plans, the discrepancies shall be reported immediately in writing to the permittee and to the Building Official.

H. If the civil engineer, the soils engineer, or the engineering geologist of record is changed during grading, the work shall be stopped until the replacement has agreed in writing to accept their responsibility within the area of technical competence for approval upon completion of the work. It shall be the duty of the permittee to notify the Building Official in writing of such change prior to the recommencement of such grading.

I. As a condition of the permit, the Building Official may require the permittee to provide, at permittee's expense, a Geotechnical Engineer or Civil Engineer to perform continuous inspection work, and upon completion of the work to provide a written statement acknowledging that they have inspected the work and that in their professional judgment the work was performed in accordance with the approved plans and specifications. The permittee shall make contractual arrangements for such services and be responsible for payment of all costs. Continuous inspection by a Geotechnical Engineer or Civil Engineer shall include, but not be limited to, the following situations:

1. During the preparation of a site for the placement of fills which exceed five (5') feet in depth on slopes which exceed ten percent (10%) and during the placing of such fills; however, for vehicular pathways, fill placement shall be continuously inspected when fills exceed ten (10') feet in height.

2. During the preparation of a site for the placement of any fill and during the placement of such fill which is intended to support any building or structure.

3. During the installation of subsurface drainage facilities.

Reports filed by the Geotechnical Engineer or Civil Engineer regarding special inspection shall state in writing that from his personal knowledge the work performed during the period covered by the report has been performed in substantial accordance with the approved plans and specifications.

The use of a Geotechnical Engineer or Civil Engineer for inspections shall not preclude the Building Official from conducting inspections using their own or other authorized inspectors as may be necessary.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))

A. Upon completion of the rough grading work and at the final completion of the work, the following reports and drawings and supplements thereto are required for engineered grading or when professional inspection is performed for regular grading, as applicable.

1. An as-built grading plan prepared by the civil engineer retained to provide such services in accordance with Section 14.12.150.E showing original ground surface elevations, as-graded ground surface elevations, lot drainage patterns, and the locations and elevations of surface drainage facilities and of the outlets of subsurface drains. As-constructed locations, elevations and details of subsurface drains shall be shown as reported by the soils engineer.

Civil engineers shall state that to the best of their knowledge the work within their area of responsibility was done in accordance with the final approved grading plan.

2. A report prepared by the soils engineer retained to provide such services in accordance with Section 14.12.150.C of this Chapter, including locations and elevations of field density tests, summaries of field and laboratory tests, other substantiating data, and comments on any changes made during grading and their effect on the recommendations made in the approved soils engineering investigation report. Soils engineers shall submit a statement that, to the best of their knowledge, the work within their area of responsibilities is in accordance with the approved soils engineering report and applicable provisions of this Section.

3. A report prepared by the engineering geologist retained to provide such services in accordance with Section 14.12.150.E, including a final description of the geology of the site and any new information disclosed during the grading and the effect of same on recommendations incorporated in the approved grading plan. Engineering geologists shall submit a statement that, to the best of their knowledge, the work within their area of responsibility is in accordance with the approved engineering geologist report and applicable provisions of this Chapter.

4. The grading contractor shall submit, in a form prescribed by the Building Official, a statement of conformance to said as-built plan and the specifications.

B. The permittee shall notify the Building Official when the grading operation is ready for final inspection. Final approval shall not be given until all work, including installation of all drainage facilities and their protective devices, and all erosion-control measures have been completed in accordance with the final approved grading plan, and the required reports have been submitted.

(Ord. 2374. (01/14/2014); Ord. 2424. (12/13/2016); Ord. 2473. (01/14/2020); Ord. 2515. (12/06/2022); Ord. 2515. (12/13/2022); Ord. 2531. (10/24/2023))