Article IV — GRADING DESIGN STANDARDS

5.1

Grading and erosion control plans shall conform to the standards set forth herein. In the event of conflict between the grading standards set forth in this Chapter and other requirements of law, the more stringent or protective requirement shall prevail. The following general requirements apply to all grading:

a)

Minimize the amount of soil exposed at any one (1) time by proper coordination of grading and construction.

b)

Divert runoff away from steep, bare slopes or other critical areas with proper diversion structures such as barriers, berms, ditches, or other devices.

c)

Design grading slopes to be compatible with adjacent area and to cause minimal disturbance to the terrain and natural features.

d)

Prevent silt, sedimentation, dust or other materials exceeding the natural background levels from leaving the disturbed area through the use of Best Management Practices.

e)

Retain as much natural vegetation as possible on site to stabilize hillsides, retain moisture, minimize erosion and siltation and preserve natural habitat.

f)

Conduct routine site inspections to ensure that erosion and dust control measures are in place and functioning properly and to correct problems where needed.

g)

Grading proposed in areas of Naturally Occurring Asbestos (NOA) shall comply with the Asbestos Dust Mitigation Measures.

h)

Certain projects may be required to obtain coverage under the Construction General Permit for Discharges of Storm Water administered by the Regional Water Quality Control Board. As a grading permit condition of approval, applicants may be required to file a Notice of Intent (NOI) to comply with the Construction General Permit.

6.1

Standard hours of operation shall be 7:00 a.m. until 7:00 p.m. pursuant to the Lake County Zoning Ordinance, Section 41.1(e).5. Grading activities between the hours of 7:00 p.m. and 7:00 a.m. are not permitted unless determination is made by the Administrative Official that the proposed activities will not be detrimental to the health, safety and welfare of the adjacent and neighboring properties.

6.2

The Administrative Official may permit extended hours of operation, if deemed not to be detrimental to the health, safety or welfare of adjacent properties, and if written request for such operations is submitted to the Community Development Department prior to commencement of such activities.

(Ord. No. 2830, § 1, 7-17-2007)

7.1

The Erosion Hazard Rating (EHR) system is used to classify the erodibility of soils based on their classification in the current Lake County Soil Survey. The classification organizes soils into three (3) categories: slight, moderate, and severe Erosion Hazard Rating. The classification is determined from evaluation of a combination of the erodibility of the particular soil profile and the percent slope on which it is found. The system was developed in conjunction with the Natural Resources Conservation Service and can be found in Appendix A.

(Ord. No. 2830, § 1, 7-17-2007)

8.1

Historical, Archaeological, Paleontological, and Native American sites shall be protected to the maximum extent possible. Pursuant to California Code of Regulations, Title 20, Section 2501 et seq., all information pertaining to cultural resource documentation associated with any grading permit application is considered confidential.

8.2

Human Remains: In the event human remains are discovered during the course of any grading project there shall be no further excavation or disturbance of the site or any nearby area reasonably suspected to overlie adjacent human remains until:

a)

The County Coroner has been informed and has determined that no investigation of the cause of death is required.

b)

If remains are of Native American origin;

The descendants of the deceased have made a recommendation to the landowner or the person responsible for the excavation work, for means of treating or disposing of, with appropriate dignity, the human remains and any associated grave goods as provided in Public Resources Code Section 5097.98, or

The Native American Heritage Commission was unable to identify a descendant or the descendant failed to make a recommendation within twenty-four (24) hours after being notified by the commission.

c)

Where the following conditions occur, the landowner or his authorized representative shall rebury the Native American human remains and associated grave goods with appropriate dignity on the property in a location not subject to further subsurface disturbance.

The Native American Heritage Commission is unable to identify a descendant;

The descendant identified fails to make a recommendation; or

The landowner or his authorized representative rejects the recommendation of the descendant, and the mediation by the Native American Heritage Commission fails to provide measures acceptable to the landowner.

8.2.1

Grading shall not resume until the permittee has submitted written documentation of the date and location, as well as the circumstances under which such a discovery was made to the Community Development Department accompanied by written documentation of contact with the County Coroner.

8.2.3

If human remains are discovered before the lead agency has finished the CEQA process for issuance of a grading permit, the lead agency shall work with the Native American Heritage Commission and the applicant to develop an agreement for treating or disposing, with appropriate dignity, of the human remains and any associated grave goods.

8.3

Historical, Archaeological and Paleontological Resources

8.3.1

Grading activities shall avoid known historical resources, as well as known archeological or paleontological sites within the project site.

8.3.2

All known historic sites and all known archeological or paleontological sites shall be flagged and fenced during grading activities to prevent unintentional disturbance or destruction.

8.3.3

Any inadvertently discovered historical, archaeological, or paleontological resources shall be left unaltered. No items from the site shall be collected, disturbed or damaged and all items shall be protected until a qualified professional has examined and evaluated the location of the inadvertent discovery and has made recommendations for their treatment.

8.4

Native American Sites

8.4.1

Disturbance of known Native American sites or California Native American Graves Protection and Repatriation Act (CalNAGPRA) cultural items shall be avoided.

8.4.2

If grading activities result in inadvertent discovery of Native American sites or California Native American Graves Protection and Repatriation Act (CalNAGPRA) cultural items all grading activities shall immediately cease and the operator/discoverer must contact the local tribal office by telephone or in person, followed with written confirmation of the discovery. The operator/discoverer shall also contact the Lake County Community Development Department in the same manner listed as above.

8.4.3

Any inadvertently discovered Native American sites or CalNAGPRA cultural items shall be left unaltered. No items from the site shall be collected, disturbed or damaged and all items shall be protected until the local tribal authorities and a qualified professional have evaluated the location of the inadvertent discovery.

(Ord. No. 2830, § 1, 7-17-2007)

9.1

Watercourse Corridors:

9.1.1

Watercourse Corridors are determined as a function of Erosion Hazard Rating and the watercourse classification according to Table 1 below. Lakes that provide fish habitat shall be treated as Class I watercourses for the purposes of this Section. Lakes, vernal pools and wetlands that do not provide fish habitat but do provide habitat for aquatic non-vertebrates or macro-invertebrates shall be treated as Class II watercourses. Lakes, wetlands and vernal pools providing no habitat for aquatic life shall be treated as Class III watercourses. Corridors are measured outward from the top of the bank of a watercourse or the high water mark of a lake, wetland or vernal pool.

9.2

Standards

9.2.1

No person shall level, cause to be leveled or move, excavate, remove, dredge, pile, stockpile or otherwise change or cause to change the drainage patterns within his or their lands in any manner which changes the place of entry of such waters to his land, or to change the velocity and/or place of exit of waters from his land so as to cause damage to adjacent properties.

9.2.2

Fill placed in the FEMA-mapped floodplain shall be consistent with the requirements of Chapter 25 of the Lake County Code, Floodplain Management.

9.2.3

Excavated materials shall not be deposited or stored in or alongside watercourses, or where the materials may be displaced by high water or storm runoff mechanical disturbance, or wind erosion.

9.2.4

All soil disturbances shall use appropriate BMPs to the maximum extent practicable to prevent or minimize the discharge of sediments to the County's Storm Water Conveyance System.

9.2.5

Critical areas such as Watercourse Corridors and drainage channels shall be protected against erosion and construction site runoff.

9.2.6

Unless otherwise indicated on the approved grading plan, drainage devices and terracing shall conform to the provisions of this Section for cut and fill slopes steeper than three (3) units horizontal in one (1) unit vertical (thirty-three and one-third (33.3) percent). Cut and fill slopes shall be provided with subsurface drainage as necessary for stability.

9.2.7

All drainage devices shall be designed to carry surface water to the nearest practicable drainage facility approved by the Administrative Official. Erosion in the area of discharge shall be prevented by installation of non-erosive down drains or other devices.

9.2.8

Where necessary, check dams, riprap, interceptor drains, terraces or other devices or methods shall be employed to control erosion and ensure stability.

9.2.9

When drainage swales are used to divert surface waters, they shall be vegetated or protected, as necessary.

(Ord. No. 2830, § 1, 7-17-2007)

10.1

New road construction in State Responsibility Areas (SRA) areas shall be implemented according to standards and guidelines specified in Chapter 7 of Public Resources Code, Section 4290 and 4291, California Department of Forestry and Fire Protection, Fire Safe Regulations.

10.2

New road construction occurring concurrent with or as a result of the development of a subdivision shall conform to the Subdivision Ordinance, Chapter 17, of the Lake County Code and the Lake County Road Design and Construction Standards.

10.3

Driveways shall be constructed and surfaced in accordance with requirements of the Lake County Zoning Ordinance.

10.4

New road construction should be minimized by using existing roads when possible.

10.5

Roads should be contoured to the landscape to the maximum extent possible so as to minimize cuts, fills and vegetation clearing.

10.6

In-stream crossings shall be avoided whenever possible. Stream crossings should be designed to be consistent with the Lake County Hydrology Design Standards. California Department of Fish and Game Streambed Alteration Agreements are required for diversion or obstruction of the natural flow of, or substantial change or use of any material from the bed, channel, or bank of any watercourse or lake, or the deposit or disposal of debris, waste, or other material containing crumbled, flaked, or ground pavement where it may pass into any watercourse or lake. A 404 permit may also be required from the United States Army Corps of Engineers as well as a 401 Water Quality Certification from the California Regional Water Quality Control Board.

10.7

Road design should avoid flood plains, landslide or slip prone geologic areas, areas of highly erodible soils and mapped NOA areas when possible.

10.8

Road width and gradient should be minimized.

10.9

For commercial use, a driveway access grade of no more than eight (8) percent shall be allowed for the first forty (40) feet, thereafter a grade of over twelve (12) percent shall not be acceptable without prior approval of the Community Development Department and the Department of Public Works.

10.10

Private roads and driveways to residences shall have a gradient that is not to exceed sixteen (16) percent unless approved by the local fire district, California Department of Forestry and Fire Protection, or the Administrative Official.

10.11

All single lane roads shall provide for turnouts for passing. Turnouts should be located within visible distance of the others to allow for safe passing.

10.12

Dead end roads shall provide turnarounds at the end of the road.

10.13

Encroachment permits from the Lake County Department of Public Works or California Department of Transportation are required when any road or driveway intersects county or state roadways, or for any work within the County or State right-of-way.

10.14

No driveway shall be allowed to encroach closer than twenty (20) feet to the end or beginning of the radius on any street corner unless approved by the Department of Public Works.

10.15

The width of a driveway providing access to a parking lot from the public street or between separate parking areas on a site is to be a minimum of twelve (12) feet for one-way access, twenty (20) feet for multiple-family residential, and commercial or industrial two-way access.

10.16

No driveway entering onto a right-of-way shall exceed a width of thirty (30) feet.

(Ord. No. 2830, § 1, 7-17-2007)

11.1

Bridges built to span a watercourse shall be constructed to avoid altering the stream channel wherever possible. As much native riparian vegetation as possible shall be retained. All bridge plans shall be designed by a registered civil engineer. The bridge shall be constructed in compliance with requirements, when necessary, of the California Department of Fish and Game, the United States Army Corps of

Engineers, Lake County Hydrology Design Standards, the Lake County Floodplain Management Ordinance and any other agency with jurisdiction over the project.

(Ord. No. 2830, § 1, 7-17-2007)

12.1

General

Cuts and fills shall be limited to the minimum amount necessary to provide stable embankments and conform to the standards within this Section.

12.1.1

Grading project design and implementation shall maximize the retention of natural landforms and features. Contours, elevations and shapes of finished surfaces shall be blended with adjacent natural terrain to the maximum extent feasible.

12.1.2

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

12.1.3

All slopes shall be monitored and maintained by the permittee to assure the success of the erosion control measures and/or revegetation. Temporary or permanent irrigation shall be provided where necessary to assure the successful establishment of vegetation.

12.1.4

The faces of cut and fill slopes shall be prepared and maintained to control against erosion. This control may consist of effective planting. The protection for the slopes shall be installed as soon as practicable and prior to final inspection.

12.1.5

Any area proposed for cut or fill shall be cleared. For the purposes of this Section, clearing shall consist of removal and disposal of all trees, roots, brush or other vegetation, as well as the removal of any down timber, and debris.

12.1.6

All topsoil should be stockpiled separate from other spoils so as to preserve the resource for revegetation and contained using approved BMPs to prevent sediment-laden storm water from leaving the site.

12.2

Cuts

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

12.2.1

The slope of the cut shall be no steeper than is safe for the intended use and shall be no steeper than two (2) units horizontal in one (1) unit vertical (fifty (50) percent) unless the permittee furnishes a soils engineering and/or geology report affirming the stability and safety of a steeper slope.

12.2.2

The toe of the cut shall be made no closer to the property boundary line than one-half (0.5) the height of the slope with a minimum of two (2) feet and a maximum of ten (10) feet. The setback may be increased if interceptor drains are required. Setback dimensions shall be horizontal distances measured perpendicular to the property boundary.

12.2.3

The Administrative Official may approve alternative setbacks. The Administrative 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.

12.2.4

Trenches and pits shall be promptly backfilled and compacted to reduce the risk of erosion.

12.2.5

Excavated materials removed during grading operations shall be handled in accordance with the following methods:

a)

Stockpile sufficient topsoil onsite if necessary to use on area to be revegetated.

b)

Locate and protect stockpiled soil, using approved BMPs, so that it will not erode as a result of wind or rain.

c)

Apply mulch or other protective coverings on stockpiled material that will be exposed through the winter season.

d)

Dispose of material not intended to be used onsite in a manner and location approved by the Administrative Official and in compliance with the Asbestos Dust Mitigation Plan, if applicable.

12.3

Fills

Unless otherwise recommended in the approved soils engineering report, fills shall conform to the provisions of this Section. In the absence of an approved soils engineering report, these provisions may be waived by the Administrative Official for minor fills not intended to support structures.

12.3.1

The source for all fill materials shall be identified and submitted with the application. The Ultramafic, Serpentine Rock and Soils Map of Lake County shall be consulted to determine the potential for serpentine in fill materials. Use of serpentine material as fill shall require an Asbestos Dust Mitigation Plan. Import of serpentine fill shall require a Lake County Air Quality Management District-issued plan.

12.3.2

Fill slopes shall not be constructed on natural slopes steeper than one (1) unit vertical in two (2) units horizontal (fifty (50) percent). The ground surface shall be prepared to receive fill by removing vegetation, unsuitable fill, topsoil and other unsuitable materials, scarifying to provide a bond with the new fill and, where the slopes are steeper than one (1) unit vertical in five (5) units horizontal (twenty (20) percent) and the height is greater than five (5) feet, by benching into sound bedrock or other competent materials as determined by the soils engineer.

12.3.3

When fill is to be placed over a cut, the bench under the toe of a fill in a slope steeper than five (5) units horizontal in one (1) unit vertical (twenty (20) percent) shall be at least ten (10) feet 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.

12.3.4

The toe of the fill slope shall be made no closer to the property boundary line than one-half (0.5) the height of the slope with a minimum of two (2) feet and a maximum of twenty (20) feet. Setback dimensions shall be horizontal distances measured perpendicular to the property boundary. 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 Administrative 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:

a)

Additional setbacks.

b)

Provisions for retaining or slough walls.

c)

Stabilization of the fill slope surface to minimize erosion.

d)

Provisions for the control and protection of surface waters.

The Administrative Official may approve alternative setbacks. The Administrative 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.

12.3.5

Unsuitable materials shall not be permitted in fills. Unsuitable fill materials include: rocks or other irreducible materials exceeding twelve (12) inches in diameter, broken asphalt, vegetation and brush, soils high in organic material or other materials not capable of proper compaction, not conducive to stability or having the potential for environmental impact.

12.3.6

Except as permitted by the Administrative Official, no rock or similar irreducible material with a maximum dimension greater than twelve (12) inches shall be buried or placed in fills. However, the Administrative Official may permit placement of larger rocks 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:

a)

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

b)

Rock sizes greater than twelve (12) inches in maximum dimension shall be ten (10) feet or more below grade, measured vertically.

c)

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

12.3.7

All fills shall be planted, mulched and maintained or otherwise protected from the effects of storm runoff and wind erosion.

12.3.8

All fills shall be compacted to a minimum of ninety (90) percent of maximum density. All fills shall be tested for relative compaction by a qualified geotechnical testing agency, unless waived by the Administrative Official.

Compaction Exceptions:

a)

Compaction may be less than ninety (90) percent of maximum density within six (6) inches of the slope surface when surface material is placed and compacted by a method acceptable to the Administrative Official for the planting of slopes.

b)

Fills not intended to support structures or roads may not need to be compacted to these standards if the Administrative Official determines that such compaction is unnecessary for safety and the purpose of the grading project.

(Ord. No. 2830, § 1, 7-17-2007)

13.1

The proposed site of the reservoir or dam should avoid locations:

a)

Identified as a lake, marsh, Class I or II Watercourse, wetland, identified on the Lake County General Plan Critical Resource Area Map, or any vernal pool habitat areas unless the project is reviewed subject to CEQA. or;

b)

Identified on any published geology or soils map as prone to slip or landslide without the preparation of a Geotechnical Report.

13.2

All construction operations shall be so conducted as to avoid stream sedimentation in accordance with the requirements of the State Water Resources Control Board and the Department of Fish and Game.

13.3

All cuts or fills shall be carried to lines, grades, and dimensions shown on the approved site plan.

13.4

Areas to be cleared shall consist of the reservoir area, site of dam embankment, a 25-foot strip adjoining the downstream toe of the dam embankment, spillway area, and borrow and stockpile areas. Clearing shall consist of removal and disposal of all trees, brush, down timber, and debris.

13.5

The entire foundation area for the dam embankment and other structures and all portions of the borrow areas shall be grubbed. Grubbing of foundation areas shall consist of the removal of all stumps and roots one and one-half (1½) inches or more in diameter to a depth of three (3) feet below natural ground surface. The borrow areas shall be grubbed to the extent necessary to obtain material free of stumps and roots. The

entire area to be occupied by the foundation of the dam shall be stripped to material having strength parameters equal to or greater than those required of the embankment material.

13.6

It is the intent of these standards that all required excavation materials suitable for embankment shall be utilized in the permanent construction. Suitable materials shall be excavated separately from the materials to be wasted. The suitable materials shall be segregated by loads during the excavation operations and shall be placed in the designated final locations directly from excavation. Excavated materials, if any, which are unsuitable for, or in excess of, dam embankment or other construction requirements, shall be disposed of within the vicinity as directed. Waste areas shall be left reasonably smooth, shall be sloped to drain, and shall be revegetated or surfaced according to the appropriate standards.

13.7

The source for all material necessary for construction of required embankments shall be identified and submitted with the application. Use of material from approved borrow areas shall be stripped of all topsoil containing humus, roots, rubbish, and other materials not suitable for placing in the compacted fill. Materials containing brush, root, sod, or other perishable materials will not be considered suitable. The sequence of stripping operations shall be coordinated with the excavation and fill so as to effect required moisture control with minimum addition of moisture to the excavated material.

13.8

Embankments shall be constructed to the lines and grades and cross-sections indicated on the approved site plan. The applicant shall maintain and protect the embankment in a satisfactory condition at all times until final completion and acceptance of all work by the Lake County Community Development Department.

13.9

The planting of trees and shrubs is not allowed on embankments and within fifteen (15) feet of the toe of the dam.

13.10

Approval of an application to construct a dam or reservoir does not grant the right to appropriate water. For information concerning water rights, applicants are referred to Division 1 of the Water Code and to the State Water Resources Control Board.

(Ord. No. 2830, § 1, 7-17-2007)

14.1

Native vegetation shall be retained and protected, where its removal is not necessary to implement the grading project or to meet fire safety regulations.

14.1.1

Where vegetation must be removed, the method shall be one that minimizes the erosive effects of the removal.

14.1.2

When vegetation is to be removed, the location of mature trees, defined as greater than five (5) inches diameter at breast height (DBH), that are to be removed and retained shall be clearly indicated. Vegetation to be preserved shall be clearly flagged or fenced off before any clearing or land disturbance begins.

14.1.3

Clearing shall be staged so as to minimize soil exposure during any one time, particularly during the winter season.

14.1.4

Cleared vegetation should be disposed of by chipping and spreading as mulch wherever feasible.

14.1.5

If vegetation disposal is proposed to be accomplished through burning, material to be burned shall be piled in a manner and in such locations as will cause the least fire risk and damage to adjacent vegetation as well as neighboring residences. Burning shall comply with the Lake County Air Quality Management District and local fire district regulations and permits.

14.2

Rangeland Management

14.2.1

Rangeland management constitutes land management practices including, but not limited to, burning, chipping, chaining and grubbing, that are related to fire control and clearing of understory vegetation without disturbing mature trees as defined by exceeding five (5) inches diameter at breast height (DBH). Rangeland management activities do not constitute agricultural activities under this Ordinance and past rangeland management activities do not fall under the definition of agricultural grading.

(Ord. No. 2830, § 1, 7-17-2007)

15.1

Whenever possible, topsoil onsite shall be separated and stored, protected from erosion and storm water runoff utilizing approved BMPs appropriate to the site conditions, in preparation of revegetation.

15.2

All land clearing that is not intended to support a structure shall be revegetated, preferably with native species consistent with fire safe practices, unless otherwise determined by the Administrative Official to be impractical due to site characteristics.

15.3

Temporary vegetation such as annual grasses and legumes shall be planted on sites that will not be brought to final grade by the end of the grading season or for sites that are likely to be re-disturbed.

15.4

Whenever practical, mulching, seeding, plantings of shrubs and trees and/or other stabilization measures shall be used for slope protection and for stabilization of soil storage areas and sediment containment systems. Preference should be given to using native, locally adapted grasses, shrubs and trees whenever feasible. Drought tolerant and fire-resistant native plants species shall be encouraged. Plants shall be maintained and watered at intervals sufficient to assure survival and growth.

15.5

Vegetation shall be maintained until permanent establishment is achieved. Temporary or permanent irrigation shall be provided where necessary to assure the successful establishment of vegetation.

(Ord. No. 2830, § 1, 7-17-2007)

16.1

Dust control measures shall be implemented on all sites to minimize fugitive dust emissions from the project site.

16.2

Asbestos dust mitigation measures shall be utilized for all grading located where Naturally Occurring Asbestos is disturbed.

16.3

Dust control is considered a temporary measure and shall be used as an interim treatment between site disturbance and final construction, paving or revegetation.

16.4

Dust control measures may consist of approved chemical, structural, or mechanical methods and shall be reapplied at the necessary intervals to prevent wind erosion.

16.5

Proper equipment and adequate water and/or dust palliatives, minimized vehicular speeds, installation and maintenance of cover crops and avoidance of work during periods of sustained high winds shall be used to

minimize airborne particulates.

16.6

Adequate dust control measures shall prevent dust from exiting the project site and prevent the occurrence of a detriment, nuisance, or annoyance or endanger the comfort, repose, health, safety of any considerable number of persons or the public or cause, or have the tendency to cause, injury or damage to business or property.

16.7

All grading operations on a project should be suspended when winds carry dust beyond the project site property lines despite the implementation of dust control measures or, in mapped NOA areas, when sustained wind speeds exceed ten (10) mph, unless adequate dust control can be maintained to prevent visible dust generation.

16.8

If the grading project is located in a mapped NOA area or if soils containing greater than one-quarter (0.25) percent asbestos are subject to disturbance, grading activities shall meet the requirements of the Asbestos Dust Mitigation Plan.

16.9

Serpentine materials shall not be used for surfacing and are required to be encapsulated and maintained with non-asbestos containing cover material that will prevent the release of asbestos fibers pursuant to the specifications of the approved plan.

(Ord. No. 2830, § 1, 7-17-2007)