Chapter 16.50 DESIGN STANDARDS PERFORMANCE REQUIREMENTS

A. Cut slopes shall generally be no steeper than two horizontal to one vertical (2:1). In special circumstances where no evidence of previous instability exists and, when recommended in the soils engineering and engineering geologic report and approved by the Director of Development Services and the City Engineer, cut slopes may be constructed steeper than two to one (2:1). The soils reports must include calculations that show that the steeper slope has a factor of safety of greater than one and one-half, both in mass stability and surficial stability. Special designs to mitigate minor surficial instability may be considered for approval by the City Engineer.

B. Slopes steeper than two to one (2:1) shall not be approved if two to one (2:1) or flatter slopes are required as a condition of prior approval of any project without appropriate revision of said condition by the approving body. Cut slopes steeper than two to one (2:1) in granite or metamorphic rock may be required to be graded with “stairstep” benches no more than one foot high cut into the surface such that the average slope of the surface conforms to this title.

C. Cut slopes in Friars Formation material shall not be steeper than three horizontal to one vertical (3:1) unless the cut slope is buttressed or otherwise supported by competent material as recommended by the Soils Engineer or geologist and approved by the City Engineer.

D. Slope stability analysis shall accompany soils engineering reports for all cut slopes over two feet in height regardless of the slope ratio. The soils engineer shall consider both gross and surficial stability of the slope and provide a written statement accompanying the slope stability analysis referencing a minimum safety factor of one and one-half. In addition, the soils engineer shall recommend alternative methods of construction or reinforced safety walls or fencing necessary to ensure surficial stability or mitigate the effects of surficial instability. These analyses shall incorporate all data and information generated by the engineering geologist, geophysicist or geologist.

E. Where public streets are to be underlain by bedrock which can be excavated by grading equipment but cannot be excavated with conventional trenching equipment, the plans shall specify a zone in the street to be undercut and replaced as compacted fill to facilitate placement of utilities without resorting to blasting.

F. Any grading plan which proposes cut slopes having a vertical height of 30 feet or greater shall be subject to the review and approval of the City Council prior to permit issuance. Any adjacent retaining wall or crib wall height shall not be included in slope height calculations.

G. Exceptions to the above may be made for temporary slopes upon written request at the discretion of the City Engineer where the public health, safety or welfare is not threatened. (Ord. 655 § 3, 2007; Ord. 518, 1999; Ord. 345, 1991)

16.50.020 Fills – Maximum slope and construction.

A. Fill slopes shall be no steeper than two horizontal to one vertical (2:1), exclusive of benches or terraces.

B. All fill slopes shall be overfilled to a distance from finished slope face that will allow compaction equipment to operate freely within the zone of the finished slope, and then cut back to the finish grade to expose the compacted core. Alternate methods may be employed by the grading contractor subject to approval by the soils engineer and City Engineer. In such instances, the grading contractor shall provide detailed specifications for the method of placement and compaction of the soil within a distance of an equipment-width from the slope face.

C. Slope stability analyses shall accompany soils engineering reports for all fill slopes over two feet in height regardless of the slope ratio. The soils engineer shall consider both the gross and surficial stability of the slope and provide a written statement accompanying the slope stability analysis referencing a minimum safety factor of one and one-half. In addition, the soils engineer shall recommend alternative methods of construction, compaction, or reinforced safety fencing necessary to provide surficial stability.

D. At least 20 percent of the field density tests taken within 100 feet of slope during grading shall be located within three feet of the final slope location, and at least one density test shall be taken in the outer one-foot of finished slope face for every 5,000 square feet of slope area.

E. Fill slopes shall not be constructed on natural slopes steeper than two horizontal to one vertical (2:1), where the fill slope toe is within 12 feet horizontally of the top of existing cut slopes or in any Friars Formation materials, unless evidence is submitted by the soils engineer and/or engineering geologist which indicates adequate stability. Any such proposed slope must be approved by the City Engineer.

F. Any grading plan which proposes fill slopes having a vertical height of 30 feet or greater shall be subject to the review and approval of the City Council prior to permit issuance. Any contiguous retaining wall or crib wall height shall not be included in slope-height calculations.

G. Exceptions to the above may be made for temporary slopes upon written request at the discretion of the City Engineer where the public health, safety or welfare is not threatened. (Ord. 345, 1991)

16.50.030 Fills – Preparation of ground.

A. The ground surface shall be prepared to receive fill by removing vegetation, noncomplying fill, topsoil and other unsuitable materials, and by scarifying to provide a bond with the new fill. Where existing slopes exceed five feet in height and/or are steeper than five horizontal to one vertical (5:1), the ground shall be prepared by benching into sound bedrock or other competent material as determined by the soils engineer and approved by the City Engineer. The lowermost bench beneath the toe of a fill slope shall be a minimum 15 feet in width. The ground surface below the toe of fill shall be prepared for sheet flow runoff, or a paved drain shall be provided.

B. Where fill is to be placed over a cut slope, the bench under the toe of the fill shall be at least 15 feet wide and shall meet the approval of the soils engineer and/or engineering geologist as a suitable foundation for fill. (Ord. 345, 1991)

16.50.040 Fills – Fill material.

A. Detrimental amounts of organic material shall not be permitted in fills. Except as outlined below, no rock or similar irreducible material with a maximum dimension greater than 12 inches shall buried or placed in fills.

B. The City Engineer may permit placement of larger rock when the soils engineer properly devises a method of placement, continuously inspects placement, and approves the soil stability and competency. The following conditions shall also apply:

1. Prior to issuance of the grading permit, potential rock disposal area(s) shall be delineated on the grading plan.

2. Rock sizes greater than 12 inches in maximum dimension shall be six feet or more below grade, measured vertically, and/or 10 feet measured horizontally from slope faces whichever is greater.

When the design of the development or covenants and restrictions clearly provide irrevocable assurance that no structure or utilities will be placed on a precisely definable area, these burial depths may be reduced with the approval of the City Engineer.

3. Rocks greater than 12 inches shall be placed so as to be completely surrounded by soils; no nesting of rocks will be permitted. (Ord. 345, 1991)

16.50.050 Fills – Compaction.

A. All fills shall be compacted to a minimum of 90 percent of maximum density as determined by ASTM D1557-78 (five layer test). Field density tests shall be performed in accordance with ASTM D1556-78, or equivalent, as approved by the City Engineer. At least 25 percent of the total tests shall be by ASTM D1556-78 to verify the accuracy of the equivalent method. All such tests shall be reasonably uniformly distributed within the fill or fill slope surface so that the representative results are obtained.

B. Locations of field density tests shall be determined by the engineer or approved testing agency, but shall be sufficient in both horizontal and vertical placement to provide representative testing of all fill placed.

C. Supplemental testing shall be done in areas of a critical nature or where special emphasis has been placed by the soils engineer or geologist. This supplemental testing shall be in addition to a traditional network of representative sampling. Where very high potential expansion characteristics exist, as defined in the City Building Code, lesser compaction may be granted by the City Engineer upon justification and recommendation by the soils engineer in relation to foundation design.

D. Sufficient maximum density determinations by test method ASTM 1557-78 shall be performed during the grading operations to verify that the maximum density curves used are representative of the material placed throughout the fill. (Ord. 705 § 2, 2010; Ord. 345, 1991)

16.50.060 Fills – Buttress/stabilization fills.

Recommendations for buttress fills or stabilization fills by the soils engineer shall be accompanied by a report setting forth the soil or geologic factors necessitating the buttress/stabilization fill, stability calculations based on both static and pseudostatic conditions (pseudostatic loads need not normally be analyzed when bedding planes are flatter than 12 degrees from the horizontal), laboratory test data upon which the calculations are based, a copy of the approved grading plan showing the location of the buttress/stabilization fill, a scaled section of the buttress/stabilization, and recommendations with details of subdrain requirements. (Ord. 345, 1991)

16.50.070 Fills – Utility line backfill.

A. Backfills for on-site utility line trenches such as water, sewer, gas, and electrical services shall be compacted and tested in accordance with the above section. Alternate materials and methods may be used for utility line backfills, provided that the material specification and method of placement are recommended by the soils engineer and approved by the City Engineer prior to backfilling.

B. The final utility line backfill report from the project soils engineer shall include a statement of compliance by the soils engineer that the tested backfill is suitable for the intended use. (Ord. 345, 1991)

16.50.080 Berms.

Unless waived by the City Engineer, a compacted earthen berm shall be constructed at the top of all slopes steeper than five to one (5:1). The berm shall conform to the slope and shall be a minimum of six inches high and one foot wide. (Ord. 655 § 3, 2007; Ord. 345, 1991)

16.50.090 Setbacks – Generally.

The setbacks and other restrictions specified by this chapter are minimum and may be increased by the City Engineer or by the recommendation of a civil engineer, soils engineer or engineering geologist if necessary for safety and stability, to prevent damage of adjacent properties from deposition or erosion or to provide access for slope maintenance and drainage. Retaining walls may be used to reduce the required setbacks when approved by the City Engineer. (Ord. 345, 1991)

16.50.100 Setbacks – Location.

The tops and toes of slopes shall be set back from the outer boundaries of the permit area, including slope rights areas and easements, and from structures, in accordance with the latest adopted version of the City Building Code. Lot lines shall be located at the top of slopes, including berms, wherever practicable. (Ord. 705 § 2, 2010; Ord. 345, 1991)

16.50.110 Design standards for setbacks.

A. Setbacks between graded slopes (cut or fill) and structures shall be provided in accordance with Figure A set out in this chapter.

Notes for Figure A:

1. Property line setbacks shall also comply with the minimums in the zoning code.

2. Setbacks apply to manufactured and natural slopes steeper than 5:1. Setbacks from flatter slopes shall meet the approval of the City Engineer.

3. “B” may be reduced if an approved drainage device is installed or the total area of “B” is less than 200 square feet with roof gutters and downspouts provided. “D” may not be reduced.

4. If a retaining wall is placed at the toe of Slope 1, “A” may be reduced to six inches. “B” remains unchanged.

5. “B” is measured from the face of the structure to the top of berm or back of retaining wall. “D” is measured from the lower outside edge of the footing along a horizontal line to the face of the slope or back of retaining wall.

6. “C” may be reduced to zero if the building permit authorizes a combination structure wall-retaining wall with adequate drainage disposal.

7. Slopes over 30 feet high are subject to City Council approval. (Ord. 345, 1991)

16.50.120 Terraces and terrace drains.

A. Terraces at least eight feet in width shall be established at not more than 30-foot vertical intervals on all cut or fill slopes to control surface drainage and debris. Where only one terrace is required, it shall be at midheight. Terrace widths shall be subtracted from the horizontal component of the slope ratio so that slope faces do not exceed the maximum slope. Accordingly, each component section of the slope between terraces will be calculated independently. Terrace widths and spacing for cut-and-fill slopes greater than 90 feet in height shall be designed by the civil engineer upon recommendation of the soils engineer and approved by the City Engineer. Suitable access shall be provided to permit proper cleaning and maintenance.

B. Terrace drains shall be constructed on all terraces, using concrete with suitable reinforcement, with a minimum gradient of three percent unless waived by the City Engineer due to special circumstances. Construction of the drains shall be such that concrete is a minimum of one-half inch below (and a maximum of four inches below) the surface elevation of the adjacent grade. The terrace drain shall have a minimum depth at the deepest point of one foot and a minimum width of three feet (measured across the top), and shall be designed to accommodate the runoff intercepted.

C. Unless otherwise approved by the City Engineer, a single run of terrace drain shall not collect more than 15,000 square feet of drainage area without discharging into a downdrain or other approved collection device. Splash walls, velocity reducers, flow spreaders and other structures shall be provided to the satisfaction of the City Engineer. All downdrains shall be constructed of concrete with suitable reinforcement and shall equal the cross-sectional area of the terrace drain or be a pipe of approved material and of 12 inches minimum diameter.

D. Construction of the terrace drains shall be as described for gutters and downdrains herein, and shall be located on the terraces with one side of the ditch at least two feet from the toe of the slope.

E. In special circumstances, when recommended in the soil engineering report, and approved by the City Engineer, fill slopes constructed at inclinations no steeper than two to one may be constructed without terraces. However, the global slope stability analysis calculations shall demonstrate a factor of safety no less than 1.5. In addition, slope stability calculations for surficial stability shall demonstrate a factor of safety no less than 1.5 for a depth of wetting corresponding to four feet and assuming slope-parallel seepage. Finally, analyses shall be submitted that demonstrate that the removal of terraces will not create adverse slope erosion debris and surface drainage conditions. (Ord. 655 § 3, 2007; Ord. 345, 1991)

16.50.130 Interceptor drains.

Concrete interceptor drains shall be installed along the top or toes of all cut or fill slopes where the tributary drainage area directs runoff over the slope or toward or along the toe of slope unless waived by the City Engineer. (Ord. 345, 1991)

16.50.140 Subsurface drainage.

A. Cut-and-fill slopes shall be provided with subsurface drainage as necessary for stability, and as recommended by the soils engineer, geologist and/or the engineering geologist.

B. All canyons and buttress fills shall be provided with subdrains approved by the City Engineer. (Ord. 345, 1991)

16.50.150 Pad grading.

Stormwater runoff from lots or adjacent properties shall not be carried over cut or fill slopes steeper than five to one (5:1). Such runoff shall be provided for as follows:

A. Whenever practicable, each lot shall be graded so that stormwater will drain from the back yard through the side yard and front yard with a grade of one percent minimum directly to an abutting street or approved drainage facility, without flowing across other lots or cut-and-fill slopes. Pads shall be rough graded to a minimum slope of one and one-half percent to ensure that finished grading provides one percent minimum slope on swales. Where the velocity of the flow is found to be erosive, an improved drainage device shall be required.

B. When the above is not possible, as determined by the City Engineer, stormwater shall be collected along the top of banks or at the rear of the graded lots by means of improved gutters, interceptor drains five feet from the structure, or in area drains, and carried to properly sized outfalls or devices which shall not be allowed to drain across the surface of sidewalks.

C. Area drains shall be sized by the engineer’s hydraulic calculations and in every case shall be a minimum of four inches in diameter and constructed of solid-wall pipe (not corrugated). Minimum slope shall be one-half percent and cleanouts shall be provided every 100 feet and at angle points and junctions in the system. An alternative overflow shall be designed and constructed to ensure the safety of the structure and adjacent properties in the event of drain blockage.

D. All foundations shall be designed and installed to produce a finished floor elevation a minimum of six inches above surrounding grade.

E. 1. No landscape area shall allow ponding of water within five feet of any structure. Irrigation and rain runoff shall not be designed to overflow sidewalks or patio areas.

2. Catchbasins and area drains shall be installed in all landscape areas adjacent to structures and bounded by hardscape areas within five feet of the structure. Catchbasins in these areas shall be provided at a minimum of every 10 feet measured longitudinally along the face of the structure.

F. Finished grading shall slope away from the perimeter of the building toward the pad swale (that goes around the building) at a slope of two percent for a minimum of five feet. This requirement shall also apply to all flatwork and landscaped areas adjacent to the structure.

G. The discharge from any downdrain, ditch or pipe shall be controlled so as to prevent the erosion of the adjacent grounds, and installed a minimum of five feet beyond any structure on top or toe of slope. Velocities shall be reduced by means of adequately sized aprons of rock, grouted riprap, or box-type energy dissipaters. Riprap sizing shall be designed based upon flow velocities and riprap shall be placed in a manner so as not to create other erosion problems and in conformance with standard specifications.

H. Surface drainage shall not be carried across a lot or parcel within three feet of a structure without the use of an approved drainage structure.

I. Roof gutters shall not be tied into sanitary sewer systems. (Ord. 705 § 2, 2010; Ord. 345, 1991)

16.50.160 Retaining walls.

A. Retaining walls may be specified by referencing a current City-adopted standard design with clear notation on the plans of specific wall heights, dimensions, reinforcement options, exceptions, and modifications. All exceptions and modifications must be justified by the engineer of work to the satisfaction of the City Engineer.

B. Any special retaining wall designs must be performed by a registered structural engineer or a registered civil engineer competent in structural calculations. Complete structural calculations must be provided to the City for review and approval. The City Engineer may require special inspections in accordance with PMC 16.52.110.

C. Cross-sectional views of all retaining walls must be provided on the grading plan.

D. All retaining walls shall include an engineered foundation drain system consisting, at a minimum, of the following:

1. A minimum four-inch-diameter solid-wall pipe with perforations, at a minimum slope of one percent, encased in approved filter rock, wrapped in an approved geotextile fabric; or

2. A prefabricated drainage system equal to Miradrain 6000 with perforated solid-wall pipe; and

3. Where determined necessary by the City Engineer, a waterproofing system and/or vertical drainage system behind the wall.

E. Where a walkway is within two feet of the top of a retaining wall greater than 30 inches in height, a guardrail 42 inches in height shall be constructed to the specifications of the latest adopted version of the City Building Code.

F. Where a driveway, roadway, or parking area is within five feet of the top of a retaining wall, a vehicle guardrail shall be constructed to the specifications of the latest adopted San Diego Regional Standard Drawings or any alternate approved by the City Engineer.

G. Where a driveway is within five feet of the top of a slope steeper than five to one (5:1), a minimum six-inch-high berm or curb shall be constructed at the edge of the driveway.

H. Wall design shall conform to the requirements of the City Zoning Code.

I. All retaining walls shall be set back a minimum of six inches from adjacent property lines.

J. Asphalt or concrete chevrons shall be installed adjacent to all curbs where the lateral grade exceeds 10 percent, except where sidewalks are installed.

K. The grading plan shall clearly indicate which walls are to be constructed as a part of this permit and which walls are to be constructed and inspected under the authority of a building permit after rough grade approval. Any temporary slopes shall be clearly shown on the plan. (Ord. 705 § 2, 2010; Ord. 345, 1991)

16.50.170 Erosion and sediment control required.

A. Plans for an erosion control system shall be prepared and submitted for the review and approval of the City Engineer as a part of any application for a permit under this division. The erosion control system shall comply with the requirements of the latest State general construction stormwater permit (NPDES Permit No. CAS000002) and any amendments thereto; the MS4 Permit; and the City’s stormwater management and discharge control ordinance (Chapter 13.09 PMC) to satisfy the requirements for erosion control and eliminate the discharge of sediment and pollutants. The erosion control plan shall include, but not be limited to, the following information:

1. Name, address and a 24-hour phone number of the owner or responsible party, and the person or contractor responsible for installing and maintaining the erosion control system and performing emergency erosion control work;

2. The name, address and signature of the civil engineer or person who prepared the plan;

3. All desilting basins, debris basins, silt traps, and other desilting, velocity retarding and protection facilities necessary to adequately protect the site and downstream properties from erosion and its effects, preserve natural hydrologic features, and preserve riparian buffers and corridors;

4. The streets, easements, drains, and other improvements;

5. The location and placement of gravel bags, diverters, check dams, slope planting, drains, and other erosion controlling devices and measures required by the BMP Manual; and

6. Access routes to all such erosion control facilities and how access shall be maintained during inclement weather.

B. Erosion control system standards shall be as follows:

1. Erosion and sediment control BMPs shall be implemented as required by the City’s BMP Manual.

2. The permittee or owner shall be responsible for control of erosion on all areas of grading until acceptance of the completed grading by the City Council. This responsibility extends to completed and occupied lots.

3. No earth or organic material shall be deposited or placed where it may be directly carried into a stream or body of standing water.

4. Maintenance and repair of required temporary sediment or siltation basins shall be provided for by the developer for a minimum of three years after completion and acceptance of the work. A special bond to ensure adequate maintenance and repair, in an amount to be determined by the City Engineer, shall be required for that period.

5. Equipment and workers for emergency work shall be made available at all times. One hundred twenty-five percent of all necessary materials shall be available on site and stockpiled at convenient locations to facilitate rapid construction of temporary devices at all times.

6. All removable protective devices shown shall be in place at the end of each working day when there is a 50 percent chance of rain within a 48-hour period. If the developer does not provide the required installation or maintenance of erosion control structures within two hours of notification at the 24-hour number on the plans, the City Engineer may order City crews or the City’s contractor to do the work or may issue contracts for such work and charge the cost of this work, along with reasonable overhead charges, to the cash deposits or other instruments implemented for this work without further notification to the owner. No additional work on the project, except erosion control work, may be performed until the full amount drawn from the deposit is restored by the developer.

7. At any time of year, an inactive site shall be fully protected from erosion and discharges of sediment. Flat areas with less than five percent grade shall be fully covered unless sediment control is provided through desilting basins at all project discharge points. A site is considered inactive if construction activities have ceased for a period of 14 or more consecutive days.

C. No grading work shall be allowed between October 1st and the following April 30th on any site when the City Engineer determines that erosion, mudflow, or sediment or silt discharge may adversely affect downstream properties, drainage courses, storm drains, streets, easements, or public or private facilities or improvements unless an approved erosion control system has been implemented on the site. If the City determines that it is necessary for the City to cause erosion control measures to be installed or cleanup to be done, the developer shall pay all of the City’s direct and indirect costs, including extra inspection, supervision and reasonable overhead charges.

D. Advanced treatment for sediment shall be required for construction sites determined by the City Engineer to be an exceptional threat to water quality. In evaluating the threat to water quality, the City Engineer shall consider the following factors:

1. Soil erosion potential or soil type;

2. The site’s slopes;

3. Project size and type;

4. Sensitivity of receiving waters;

5. Proximity to receiving waters;

6. Non-stormwater discharges;

7. Ineffectiveness of other BMPs; and

8. Any other relevant factors. (Ord. 775 § 7, 2015)

16.50.180 Debris on public street.

A. The California Vehicle Code and this code forbid the placing, dumping or depositing of dirt and rocks on the public streets or any portion of the public right-of-way. All vehicles engaged in hauling materials under the permit provisions of this division shall refrain from depositing dirt or debris on the public streets by any means, including, but not limited to, spillage from the bed of a truck or other vehicle and debris collected on the wheels of the haul vehicle.

B. The permittee conducting any earth-moving operation under this division which requires vehicles to haul earth materials on any public street shall be responsible for the complete removal of such materials from the street, including earth, mud, or other material spilled, dumped, or deposited on a public street. If the permittee fails to immediately remove completely such spillage, and it is necessary for the City to cause such removal to be made, the permittee and/or the property owner shall be liable to pay the City the full cost of such removal work plus reasonable overhead. The grading deposit may be used by the City for this purpose without notice to the owner. An additional cash deposit may be required prior to resumption of grading to ensure the cleanup of public streets. (Ord. 345, 1991)

16.50.190 Dust control.

The contractor/permittee conducting any earth-moving operation under this division shall be responsible for controlling dust at all times. (Ord. 345, 1991)

16.50.200 Protection of adjoining property.

Each adjacent owner is entitled to the lateral and adjacent support which his land receives from the adjoining land, subject to the right of the owner of the adjoining land to make proper and usual excavations on the same for purposes of construction or improvement, under the following conditions:

A. Any owner of land, or his lessee, intending to permit or to make an excavation greater than 10 feet in depth within 10 feet of his property lines shall give reasonable notice to the owner or owners of land abutting the property lines affected by such excavation, stating the depth for which such excavation is intended to be made and when the excavation will begin.

B. In making any excavation, reasonable care and skill shall be used and reasonable precautions taken that the soil of adjoining property will not cave in or settle to the detriment of any building or other structure which may be thereon. Excavations shall meet all State and Federal regulations, including, but not limited to, obtaining CAL OSHA permits.

C. No grading shall be approved which, in the opinion of the City Engineer, physically prevents the use of existing legal access to any parcel.

D. No rock blasting shall be permitted until a preblast survey of the surrounding property is conducted to the satisfaction of the City Engineer. During rock blasting, seismic recordings shall be taken for all blasts at locations and levels approved by the City Engineer. All blasting shall conform to the requirements of the City Engineer.

1. The contractor shall prepare a site plan, to scale, showing where the blasting will occur and all the buildings and utilities within 500 feet.

2. A preblast survey of all buildings within 300 feet will automatically be required. Other structures within 500 feet should be surveyed, if they are more than 15 years old and/or sensitive, such as historical buildings. The preblast surveys shall be submitted with the permit application. Alternately, a letter from an authorized survey service may be submitted with a scale drawing showing distances to all structures to be surveyed prior to the blast.

3. A seismic monitor shall be located adjacent to the closest building or most sensitive building. The seismic recordings shall be submitted to the project inspector as soon as they are available.

4. Ground accelerations shall be limited to 1.0 feet per second per second (fpss) in the area of new construction, and 0.5 fpss around older or sensitive buildings.

5. The blasting contractor shall notify in writing all residents within 500 feet of the blast area. At a minimum, the notice is to be in the form of a door-hanger stating the approximate time the blast or blasts will occur. The notices are to be in place at least 48 hours prior to blasting.

6. The applicant shall pay an appropriate administrative fee, as established by City Council resolution, which may be amended from time to time, for processing of each blasting permit. (Ord. 683 § 65, 2008; Ord. 345, 1991)

16.50.210 Drainage easement.

For all drainageways where the competent functioning of the drainageway is essential to the protection and use of multiple properties, a covenant and/or deed restriction shall be recorded by the applicant, placing the responsibility for the maintenance of the drainageways on the owner of record of each respective lot affected. Permanent off-site drainage easements, as required by the City Engineer, shall be acquired by the permittee. Such easements shall be subject to approval of the City Engineer and City Attorney and recorded prior to issuance of the grading permit. (Ord. 345, 1991)

16.50.220 Expansive soils.

A. Tests for expansive soils shall be performed on soils within four feet of the finish grade of any area intended or designed as a location for a building. Whenever expansive soils are encountered in this zone then:

1. The permittee shall cause such expansive soil to be removed to a minimum depth of four feet below finish grade and replaced with properly compacted, nonexpansive soil; or

2. The Soils Engineer may recommend a modification to the requirement for removal and replacement of the expansive soils reported on the project. In that case, the Soils Engineer shall make recommendations for the design of footings, foundations, slabs, and other load-bearing features, or for other special procedures which will alleviate any problem created by the remaining expansive soils.

B. In general, at the discretion of the Soils Engineer, expansive soil from cut areas shall be placed in the lower extremities of embankments, and nonexpansive materials shall be reserved, stockpiled, or otherwise handled so that they may be placed as a cap over expansive soils.

C. Expansive soils which cannot be disposed of on-site, as described above, shall be disposed of off-site by either:

1. Their disposal outside the City limits; or

2. Their disposal at another location within the City, provided the location is covered by a valid grading permit or stockpile permit and the expansive soils can be disposed of at such location with the written approval of the owner and Soils Engineer. (Ord. 345, 1991)

16.50.230 Asphalt concrete pavement.

A. Requirements. For the purpose of this chapter, asphalt concrete (A.C.), aggregate base (A.B.), prime coat, tack coat and seal coat shall meet the current standards of the City for road construction and/or the approval of the City Engineer.

B. Cost Estimates. Asphalt concrete is classified as a secondary drainage device when used for roadway and parking lot surfacing and other similar uses. Accordingly, the cost of all paving, with the exception of single-family driveways, shall be included in the engineer’s cost estimate.

C. Subgrade Compaction. Subgrade earth materials must be compacted to a minimum of 12 inches in depth and shall comply with all other requirements of this division.

D. Soil Sterilization. Unless otherwise approved by the City Engineer, subgrade earth materials shall be sterilized with nonpollutant materials to preclude plant growth.

E. Pavement Structural Section. The project soils engineer or design civil engineer shall recommend a pavement structural section(s) for parking lots/service roads, private streets, and dedicated streets for all developments based on:

1. Soils tests of the subgrade soil(s) performed in accordance with the latest revision of ASTM 1557-82; and

2. Anticipated traffic and/or loading conditions. Design shall be in accordance with the CalTrans Highway Design Manual. The structural sections shall be not less than the minimum standards established by the City. Minimum traffic index for pavement design shall be 4.5.

F. All adjoining pavement edges shall be saw-cut for butt joints or ground with a minimum of one and one-half inches of asphalt applied. No feathering is allowed.

G. Minimum overlay depth shall be one and one-half inches.

H. A minimum cross slope of two percent shall be utilized on all asphalt road and driveway pavement sections. Parking lots shall have a minimum cross slope of one percent. Concrete drainage structures placed at less than one percent slope must have grade stakes set by the engineer of work at no greater than 20-foot intervals.

I. Maximum gradient for parking stalls shall be eight percent.

J. Maximum gradient change in driveways and parking lots shall be eight percent in every 20 horizontal feet. (Ord. 705 § 2, 2010; Ord. 553, 2002; Ord. 345, 1991)

16.50.240 Retention of topsoil.

Unless otherwise specifically noted on the approved plan, the topsoil removed in conjunction with grading activities shall be retained on-site and reused in areas slated for on-site landscaping, plant habitat restoration or revegetation, as deemed appropriate by the Director of Development Services. (Ord. 518, 1999; Ord. 345, 1991)