Article VIII. - Standards.

Sec. 11-22.Purpose.

Sec. 11-23.Cuts and fills.

Sec. 11-24.Dams and reservoirs.

Sec. 11-25.Drainage.

Sec. 11-26.Soil and other pollutant discharges.

Sec. 11-27.Storm water best management practices.

Sec. 11-28.Operations during the rainy season.

Sec. 11-29.Removal of vegetation.

Sec. 11-30.Revegetation.

Sec. 11-31.Protection of human remains and archaeological resources.

Sec. 11-32.Protection of watercourses.

Sec. 11-33.Setbacks for streams.

Sec. 11-34.Setbacks for lakes and ponds.

Sec. 11-35.Setbacks for wetlands.

Sec. 11-22. - Purpose.

This article provides ministerial standards for the proper conduct of grading, drainage improvement, and vineyard and orchard site development. All grading, drainage improvement, and vineyard and orchard site development shall be conducted in a manner consistent with the requirements of this article, regardless of whether a permit is required by this chapter.

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-23. - Cuts and fills.

(a) General. Cuts and fills shall be designed and constructed in compliance with the following requirements.

(1) Areas of Cuts and Fills. Cuts and fills shall be limited to the amount necessary for the intended use.

(2) Final contours. Contours, elevations, and shapes of finished surfaces shall be blended with adjacent natural terrain to achieve a consistent grade and natural appearance as follows:

(i) The top of cut slopes shall be rounded off to blend with the natural terrain.

(ii) Borders of cut slopes and fills shall be rounded off to a minimum radius of 5 feet to blend with the natural terrain.

(b) Cuts. Cuts shall be designed and constructed in compliance with the following requirements.

(1) Slope. The slope of cut surfaces shall be no steeper than two (2) units horizontal to one (1) unit vertical (fifty percent (50%)), unless a soils report justifies a steeper slope.

(2) Terracing and Drainage. Terracing and drainage of cuts shall be provided as required by subsection (d).

(c)   Fills. Fills shall be designed and constructed in compliance with the following requirements.
            (1)   Fill Location. Fill shall not be placed on natural slopes steeper than two (2) units horizontal to one (1) unit vertical (fifty
               percent (50%)).
            
(2)   Surface Preparation. Ground surfaces shall be prepared to receive fill by removing vegetation, topsoil, and other unsuitable
               materials, and scarifying the ground to provide a bond with the fill material.
            
(3)   Benching. Benching into sound bedrock or other competent material, as determined by a civil engineer, shall be required where
               existing grade is at a slope steeper than five (5) units horizontal to one (1) unit vertical (twenty percent (20)) and the
               depth of the fill exceeds five (5) feet. Benching shall be provided in accordance with Figure 11-1, subject also to the following
               requirements:
               (i)   A key at least ten (10) feet in width and two (2) feet in depth shall be installed.
(ii)   The key shall be installed at least one (1) foot into sound bedrock or other competent material.
(iii)   The area beyond the toe of the fill shall be sloped for sheet overflow or a non-erosive drain shall be provided.
(iv)   Cuts for benching and keys shall be accepted by a soils engineer as a suitable foundation for fill prior to the placement
                  of the fill material.
               

[IMAGE BELOW]

Figure 11-1—Benching Details

(4) Fill Material. Fill material shall not include organic, frozen, or other deleterious materials. No rock or similar irreducible material greater than 6 inches in any dimension shall be included in fills, except where a soils engineer devises a method of placement of larger rock, continuously inspects its placement, and approves fill stability, subject also to the following requirements:

(i) Potential rock disposal areas shall be shown on the plans and specifications.

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

(5) Fill Placement. Fills shall be constructed in lifts not exceeding eight (8) inches in depth. Completed fills shall be stable, well-integrated, and bonded to adjacent materials and the materials on which they rest. Fills shall be competent to support anticipated loads and be stable at the design slopes shown on the approved plans and specifications.

(6) Compaction.

(i) Fills Intended to Support Structures or Surcharges. Fills intended to support structures or surcharges shall be compacted to a minimum of ninety percent (90%) of maximum dry density, as determined by ASTM D 1557, Modified Proctor.

(ii) Fills Not Intended to Support Structures or Surcharges. Fills not intended to support structures or surcharges shall be compacted as follows:

(A) Fills greater than three (3) feet in depth shall be compacted to the density specified by a soils engineer.

(B) Fills no greater than three (3) feet in depth shall be compacted to the density necessary for the intended use.

(7) Slope. The slope of fill surfaces shall be no steeper than two (2) units horizontal to one (1) unit vertical (fifty percent (50 %)), unless a soils report justifies a steeper slope.

(8) Limitation on Fill in Flood-prone Urban Area. No fill shall be placed in the flood-prone urban area, unless an engineering analysis demonstrates that no adverse impact to drainage within the flood-prone urban area will result from the fill placement and related improvements.

(9) No Net Fill in Special Flood Hazard Areas. No fill shall be placed in any special flood hazard area, unless an engineering analysis demonstrates that no reduction in flood storage capacity within the special flood hazard area will result from the fill placement and related improvements.

(10) Terracing and Drainage. Terracing and drainage of fills shall be provided as required by subsection (d).

(d) Terracing and Drainage of Cuts and Fills. Terracing and drainage of cuts and fills shall be designed and constructed to ensure the integrity of the cuts and fills. The following requirements shall apply only to cuts and fills with surface slopes steeper than 3 units horizontal to one (1) unit vertical (thirty-three percent (33%). Additional requirements applicable to the provision of drainage improvements are established by Section 11-25.

(1) Agricultural Grading. Terracing and drainage of cuts and fills for agricultural grading shall be designed by a civil engineer and constructed in compliance with the civil engineer's requirements.

(2)   Construction Grading. Terracing and drainage of cuts and fills for construction grading shall conform to the following requirements.
               (a)   Terraces. Terraces shall be established on cut and fill slopes to control surface drainage and debris. Suitable access shall
                  be provided to permit proper cleaning and maintenance of terraces.
                  (A)   For cut and fill slopes up to thirty (30) feet in vertical height, terraces need not be provided.
(B)   For cut and fill slopes greater than thirty (30) feet and up to sixty (60) feet in vertical height, one (1) terrace at least
                     six (6) feet in width shall be established at mid-height.
                  
(C)   For cut and fill slopes greater than sixty (60) feet and up to one hundred twenty (120) feet in vertical height, terraces
                     at least six (6) feet in width shall be established at not more than thirty (30) foot intervals or one (1) terrace at least
                     twelve (12) feet in width shall be established at mid-height.
                  
(d)   For cut and fill slopes greater than one hundred twenty (120) feet in vertical height, terrace widths and spacing shall be
                     designed by a civil engineer.
                  
(ii)   Terrace Drainage.
                  (A)   Swales or Ditches. Swales or ditches shall be provided on terraces, and shall:
                     a.   Have a minimum gradient of twenty (20) units horizontal to one (1) unit vertical (five percent (5%));
b.   Be paved with reinforced concrete not less than three (3) inches in thickness, or with other materials suitable to the application;
                        and
                     
c.   Have a minimum depth of one (1) foot and a minimum width of five (5) feet.
(B)   Limitation on Single Run of Swale or Ditch. A single run of swale or ditch shall not collect runoff from a tributary area
                     exceeding thirteen thousand five hundred (13,500) square feet (projected) without discharging into a down drain.
                  
(iii)   Subsurface Drainage. Cut and fill slopes shall be provided with subsurface drainage as necessary for stability.
(iv)   Building Pad Drainage. Building pads shall have a drainage gradient of fifty (50) units horizontal to one (1) unit vertical
                  (two percent (2%)) toward approved drainage improvements.
               
(v)   Surface Interceptor Drains. Surface interceptor drains shall be installed along the top of all cut and fill slopes where the
                  tributary drainage area above slopes towards the cut or fill and has a drainage path greater than forty (40) feet measured
                  horizontally. The drains shall be paved with reinforced concrete not less than three (3) inches in thickness, or with other
                  materials suitable to the application. The drains shall be designed to meet the SCWA Flood Control Design Criteria for a one
                  hundred (100) year design discharge. This surface interceptor drains requirement shall not apply to outslope constructed roadways
                  designed to prevent the concentration of storm water, provided that the stability of the cut and fill slope is maintained.
               

(e) Setbacks. Cut and fill slopes shall be set back from property lines in compliance with the following requirements. Setback dimensions shall be measured perpendicular to the property line and shall be as shown in Figure 11-2.

(1) Top of Slope. The setback at the top of a slope shall be not be less than that shown in Figure 11-2, or than is required to accommodate any required surface interceptor drains, whichever is greater.

(2) Toe of Slope. The setback at the toe of a slope shall not be less than that shown in Figure 11-2.

[IMAGE BELOW]

Figure 11-2—Cut and Fill Slope Setback Requirements

(f) Protection of Footings, Buildings, and Structures. Footings that may be affected by any excavation shall be underpinned or otherwise protected against settlement and shall be protected against lateral movement. Fills or other surcharge loads shall not be placed adjacent to any building or structure unless the building or structure is capable of withstanding the additional loads caused by the fill or surcharge. The rights of adjacent affected property owners shall be as set forth in Section 832 of the Civil Code.

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-24. - Dams and reservoirs.

(a)   Dams and Reservoirs Subject to County Jurisdiction. Dams and reservoirs within the county's jurisdiction shall be designed
            and constructed in compliance with the requirements of this chapter and the California Division of Safety of Dams Guidelines
            for Small Dams, except that:
            (1)   Minimum Freeboard and Residual Freeboard. The minimum freeboard (vertical distance from spillway crest to dam crest or reservoir
               crest where there is no dam) for spillways shall be specified by a civil engineer. The minimum residual freeboard (vertical
               distance from maximum reservoir stage for spillway design flood to dam crest or reservoir crest where there is no dam) shall
               be 1.5 feet.
            
(2)   Compaction. Embankments shall be compacted to a minimum of ninety percent (90%) of maximum dry density, as determined by ASTM
               D 1557, Modified Proctor.
            
(3)   Low Level Outlet. A low level outlet need not be provided where the reservoir floor is below grade and a pump capable of emptying
               or lowering the reservoir in case of emergency or for inspection and maintenance is installed.
            

(b) Dams and Reservoirs Subject to State Jurisdiction. Dams and reservoirs within the state's jurisdiction shall be designed and constructed in compliance with the requirements of the California Division of Safety of Dams.

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-25. - Drainage.

(a) Management of Storm Water. Grading and vineyard and orchard site development shall include the drainage improvements and/or other methods necessary to manage storm water runoff in compliance with the permit authority's best management practices guide.

(b) Natural Drainage Patterns and Storm Water Levels. Grading, drainage improvement, and vineyard and orchard site development shall be designed to maintain off-site natural drainage patterns, and limit post-development storm water levels in compliance with the permit authority's best management practices guide.

(c) Design and Construction of Drainage Improvements. Drainage improvements shall be designed and constructed in compliance with the permit authority's best management practices guide. Drainage improvements required for cuts and fills are also subject to Section 11-23(d).

(d) Disposal of Storm Water. Drainage improvements shall carry storm water to the nearest practicable disposal location and shall dissipate the energy or diffuse the flow prior to releasing the storm water off the site.

(e) Prevention of Soil Loss. Drainage improvements shall prevent or minimize soil loss through the use of storm drain culverts (pipes), storm drain inlets and outlets, storm drain outfalls, energy dissipators, flow dispersion, check dams, rolling dips, critical dips, proper location and sizing of culverts, revegetation of exposed or disturbed slopes, minimizing cross drains through road outsloping, minimizing the use of artificial slopes, and other best management practices referenced or detailed in the permit authority's best management practices guide.

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-26. - Soil and other pollutant discharges.

Grading, drainage improvement, and vineyard and orchard site development shall be designed and conducted in compliance with the following requirements.

(a) During operations, soil and other pollutant discharges shall be prevented or controlled through the use of best management practices in compliance with the permit authority's best management practices guide.

(b) Prior to final inspection, all disturbed surfaces shall be revegetated as provided by Section 11-30, unless covered with impervious or other improved surfaces authorized by the approved plans and specifications, and permanent best management practices referenced or detailed in the permit authority's best management practices guide shall be installed to control soil and other pollutant discharges.

(c) Post-development, soil and other pollutant discharges shall be limited in compliance with the permit authority's best management practices guide.

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-27. - Storm water best management practices.

Grading, drainage improvement, and vineyard and orchard site development shall be conducted in compliance with the following requirements.

(a) During the rainy season, storm water best management practices referenced or detailed in the permit authority's best management practices guide shall be implemented and functional on the site at all times.

(b) During the non-rainy season, on any day when the National Weather Service forecast is a chance of rain of thirty (30) percent or greater within the next twenty-four (24) hours, storm water best management practices referenced or detailed in the permit authority's best management practices guide shall be implemented and functional on the site if necessary to prevent soil and other pollutant discharges.

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-28. - Operations during the rainy season.

Grading, drainage improvement, and vineyard and orchard site development shall be conducted in compliance with the following requirements during the rainy season (October 15 through April 15).

(a) Construction Grading and Drainage Improvement. Construction grading and drainage improvement shall be permitted during the rainy season only when on-site soil conditions permit the work to be performed in compliance with this chapter. The area of erodible land exposed at any one (1) time during the work shall not exceed one (1) acre or twenty percent (20%)of the site, whichever is greater, and the time of exposure shall be minimized to the maximum extent practicable.

(b)   Agricultural Grading and Drainage Improvement, and Vineyard and Orchard Site Development.
               (1)   Agricultural grading and drainage improvement, and initial land preparation work for vineyard and orchard planting, shall
                  be permitted during the rainy season only from April 1 to April 15, and only when on-site soil conditions permit the work
                  to be performed in compliance with this chapter.
               
(2)   Initial land preparation work for vineyard and orchard replanting shall be permitted during the rainy season only from October
                  15 to November 15 and from April 1 to April 15, and only when on-site soil conditions permit the work to be performed in compliance
                  with this chapter.
               
(3)   Final land preparation and planting work for vineyard and orchard planting and replanting shall be permitted during the rainy
                  season only when on-site soil conditions permit the work to be performed in compliance with this chapter.
               

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-29. - Removal of vegetation.

Grading, drainage improvement, and vineyard and orchard site development shall be designed and conducted in compliance with the following requirements.

(a) The limits of grading, drainage improvement, and vineyard or orchard site development shall be defined and marked on the site to prevent damage to surrounding vegetation.

(b) Any existing vegetation within the limits of grading, drainage improvement, or vineyard or orchard site development that is to remain undisturbed by the work shall be identified and protected from damage by marking, fencing, or other measures.

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-30. - Revegetation.

Grading, drainage improvement, and vineyard and orchard site development shall replant disturbed surfaces in compliance with the approved plans and specifications and the following requirements.

(a) Preparation for Revegetation. Topsoil removed from the surface in preparation for grading, drainage improvement, and vineyard and orchard site development shall be stored on or near the site and protected from soil loss while the work is underway, provided that such storage shall not cause damage to root systems of trees intended to be preserved.

(b) Methods of Revegetation. Mulching, seeding, planting of groundcover, shrubs or trees, or other suitable stabilization measures shall be used to protect exposed soil to minimize soil loss, and to maximize slope stability. Use of drought-tolerant, fire resistant native plant species is encouraged; use of invasive plant species identified in the permit authority's best management practices guide is prohibited.

(c)   Timing of Revegetation Measures. Temporary or permanent revegetation shall be installed as soon as practical after vegetation
            removal, but in all cases prior to:
            Permanent revegetation or landscaping shall be installed prior to final inspection.
            
            
            (1)   October 15 for all grading and drainage improvement;
(2)   October 15 for all initial land preparation work for vineyard and orchard planting, and all final land preparation and planting
               work; and
            
(3)   November 15 for all initial land preparation work for vineyard and orchard replanting.

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-31. - Protection of human remains and archaeological resources.

In the event that human remains or archaeological resources are discovered during grading, drainage improvement, and vineyard and orchard site development, all work shall be halted in the vicinity of the find, the permit authority shall be notified, and the following shall occur before work may be resumed:

(a) Human Remains. If human remains or suspected human remains are discovered, the permittee or the property owner shall notify the county coroner and comply with all state law requirements, including Health and Safety Code Section 7050.5 and Public Resources Code Section 5097.98, to ensure proper disposition of the human remains or suspected human remains, including those identified to be Native American remains.

(b) Archaeological Resources. If archaeological resources or suspected archaeological resources are discovered, the permit authority shall notify the State Historic Preservation Officer and the Northwest Information Center at Sonoma State University, and the permittee or the property owner shall retain a qualified archeologist to evaluate the find to ensure proper disposition of the archaeological resources or suspected archaeological resources. All costs associated with the evaluation and mitigation of the find shall be the responsibility of the permittee or the property owner. The permit authority shall provide notice of the find to any tribes that have been identified as having cultural ties and affiliation with the geographic area in which the archaeological resources or suspected archaeological resources were discovered, if the tribe or tribes have requested notice and provided a contact person and current address to which the notice is to be sent. The permit authority may consult with and solicit comments from notified tribes to aid in the evaluation, protection, and proper disposition of the archaeological resources or suspected archaeological resources. The need for confidentiality of information concerning the archaeological resources or suspected archaeological resources shall be recognized by all parties. For the purposes of this section, archaeological resources include historic or prehistoric ruins, burial grounds, pottery, arrowheads, midden, or culturally modified soil deposits. Artifacts associated with prehistoric ruins include humanly modified stone, shell, bone, or other cultural materials such as charcoal, ash, and burned rock indicative of food procurement or processing activities. Prehistoric domestic features include hearths, fire pits, or floor depressions; mortuary features are typically represented by human skeletal remains.

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-32. - Protection of watercourses.

Grading, drainage improvement, and vineyard and orchard site development within, adjacent to, or involving the alteration of watercourses shall comply with the provisions of Article II (Water Clarity) of Chapter 23 of this code and the following requirements.

(a) Flood Carrying Capacity. The flood carrying capacity of any altered or relocated portion of a watercourse shall be maintained.

(b) Obstruction of Watercourses. Watercourses shall not be obstructed unless alternate drainage improvements complying with Section 11-25 are installed.

(d) Heavy Equipment. Heavy equipment shall not cross or disturb channels of actively flowing streams without best management practices referenced or detailed in the permit authority's best management practices guide in place.

(e) Materials Storage. Excavated materials and soil amendment and fertilizing materials shall not be deposited or stored in or adjacent to a watercourse where they can be washed away by high water or storm runoff.

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-33. - Setbacks for streams.

Grading and vineyard and orchard site development shall be set back from streams in compliance with the requirements in Table 11-5, unless stricter requirements are established in the general plan, local coastal program, and/or zoning code. Existing vegetation shall be retained in setback areas to filter soil and other pollutants carried in storm water. Vegetative filter strips may be installed in setback areas in compliance with the permit authority's best management practices guide to enhance filtration. Grassy avenues and turnarounds for agricultural crops may be located within vegetative filter strips. This setback requirement shall not apply to grading for bridges, stream crossings, and approaches; dams and reservoirs; drainage improvements; trails; public projects; resource conservation, restoration, or enhancement projects; or stream bank restoration or stabilization.

Table 11-5—Stream Setback Requirements

Grading and Vineyard and Orchard Site Development for Vineyard and Orchard Planting

[TABLE BELOW]

Type of Stream	Soils on Grading or Planting Area	Natural Slope of Grading or Planting Area	Setback
Stream designated in the general plan, local coastal program, and/or zoning code	No highly erodible soils	Slope is no steeper than 15 percent	25 feet from the top of bank
Stream designated in the general plan, local coastal program, and/or zoning code	No highly erodible soils	Slope is no steeper than 15 percent	50 feet from the top of bank
Stream designated in the general plan, local coastal program, and/or zoning code	Any highly erodible soils	Slope is no steeper than 10 percent	25 feet from the top of bank
Stream designated in the general plan, local coastal program, and/or zoning code	Any highly erodible soils	Slope is steeper than 10 percent	50 feet from the top of bank
Stream not designated in the general plan, local coastal program, and/or zoning code	Not applicable	Not applicable	25 feet from the top of bank

Vineyard and Orchard Site Development for Vineyard and Orchard Replanting

[TABLE BELOW]

Type of Stream	Soils on Replanting Area	Natural Slope of Replanting Area	Setback
Stream designated in the general plan, local coastal program, and/or zoning code	Not applicable	Not applicable	25 feet from the top of bank
Stream not designated in the general plan, local coastal program, and/or zoning code	Not applicable	Not applicable	25 feet from the top of bank

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-34. - Setbacks for lakes and ponds.

Grading and vineyard and orchard site development shall be set back from lakes and ponds in compliance with the requirements in Table 11-6, unless stricter requirements are established in the general plan, local coastal program, and/or zoning code. Existing vegetation shall be retained in setback areas to filter soil and other pollutants carried in storm water. Vegetative filter strips may be installed in setback areas in compliance with the permit authority's best management practices guide to enhance filtration. Grassy avenues and turnarounds for agricultural crops may be located within vegetative filter strips. This setback requirement shall not apply to grading for drainage improvements; trails; public projects; resource conservation, restoration, or enhancement projects; or lake or pond maintenance.

Table 11-6—Lake and Pond Setback Requirements

[TABLE BELOW]

Type of Water Body	Setback
Lake	50 feet from the high water mark, unless the area slopes away from the lake and the grading or vineyard or orchard site development will not compromise the structural integrity of the lake.
Pond	50 feet from the high water mark, unless the area slopes away from the pond and the grading or vineyard or orchard site development will not compromise the structural integrity of the pond.

(Ord. No. 5891, § 7, 12-9-2008.)

Sec. 11-35. - Setbacks for wetlands.

Grading, drainage improvement, and vineyard and orchard site development shall be set back from wetlands in compliance with the requirements in Table 11-7, unless stricter requirements are established in the general plan, local coastal program, and/or zoning code. Existing vegetation shall be retained in setback areas to filter soil and other pollutants carried in storm water. Vegetative filter strips may be installed in setback areas in compliance with the permit authority's best management practices guide to enhance filtration. Grassy avenues and turnarounds for agricultural crops may be located within vegetative filter strips.

Table 11-7—Wetlands Setback Requirements

[TABLE BELOW]

Type of Wetlands	Setback
Wetlands designated in the general plan, local coastal program, and/or zoning code	100 feet from the delineated edges
Wetlands not designated in the general plan, local coastal program, and/or zoning code	50 feet from the delineated edges, unless a wetlands biologist recommends a lesser setback

(Ord. No. 5891, § 7, 12-9-2008.)