Chapter 15.05
SITE DEVELOPMENT REGULATIONS

Sections:

15.05.010    Purpose.

15.05.020    Definitions.

15.05.030    Applicability.

15.05.040    Administration.

15.05.050    Deviations.

15.05.060    Site development permit required.

15.05.070    Preliminary grading worksheet.

15.05.080    Repealed.

15.05.090    Repealed.

15.05.100    Operating conditions and standards of performance.

15.05.110    Grading – Land development projects.

15.05.120    Grading – Individual lots.

15.05.130    Drainage.

15.05.140    Slopes.

15.05.150    Fill.

15.05.160    Rock and retaining walls.

15.05.170    Utilities.

15.05.180    Driveways – Design.

15.05.190    Inspections.

15.05.200    Final approval.

15.05.210    Stop work order/permit revocation.

15.05.220    Forest practices.

15.05.230    Repealed.

15.05.010 Purpose.

(1) This chapter is intended to regulate clearing, grading, and earthwork construction, including cuts and fills, within the City of Woodinville in order to protect public health, safety, welfare, and aesthetics by:

(a) Minimizing adverse stormwater impacts generated by the removal of vegetation and alteration of landforms;

(b) Protecting water quality from the adverse impacts associated with erosion and sedimentation;

(c) Minimizing aquatic and terrestrial wildlife habitat loss caused by the removal of vegetation;

(d) Protecting critical areas from adverse clearing and grading activities; and

(e) Preventing damage to property and harm to persons caused by excavations and fills. (Ord. 635 § 1, 2016)

15.05.020 Definitions.

Certain words and phrases used in this chapter, unless otherwise clearly indicated by their context, mean as follows:

(1) “Applicant” means a property owner or any person or entity acting as an agent for the property owner in an application for a development proposal, permit, or approval.

(2) “Bench” is a relatively level step excavated or constructed into earth material on which fill is to be placed.

(3) “Berm” is a mound or raised area used for the purpose of screening a site or operation.

(4) “Best management practices (BMPs)” mean the best available and reasonable physical, structural, managerial, or behavioral activities that, when used singly, or in combination, eliminate or reduce potential adverse impacts associated with clearing and grading.

(5) “Borrow” means earth material used in grading a site. This includes soil and rock material utilized from the site, moved within the site, or imported to the site.

(6) “Civil engineer” means an engineer who is licensed as a professional civil engineer by the State of Washington in accordance with Chapter 18.43 RCW.

(7) “Clearing” means the limbing, pruning, trimming, topping, cutting, or removal of vegetation or other organic plant matter by physical, mechanical, chemical, or other means.

(8) “Compaction” is the densification of fill soil or other materials by mechanical means.

(9) “Critical areas” means the environmentally sensitive areas described in WMC Title 21.

(10) “Development proposal” means any activities requiring a permit or other approval from the City of Woodinville relative to the use or development of land.

(11) “Director” means the Public Works Director or the Development Services Director or his/her designee.

(12) “Earth material” is any rock, natural soil or fill, or any combination thereof.

(13) “Engineering geologist” means a practicing engineering geologist licensed in the State of Washington.

(14) “Erosion” is the wearing away of the ground surface as the result of the movement of wind, water and/or ice.

(15) “Excavation” is the removal of earth material. The term “cut” can also be used to describe excavation.

(16) “Fill” is a deposit of earth material placed by mechanical or other means.

(17) “Geotechnical engineer” or “soils engineer” means a civil engineer who is licensed in the State of Washington and who has a minimum of five years of experience in the field of geotechnical, geological, or mining engineering.

(18) “Grade” means the elevation of the ground surface.

(a) “Existing grade” is the grade of the ground surface prior to any grading activity requested by the applicant at the time of permit application.

(b) “Rough grade” is the stage at which the grade approximately conforms to the approved site development permit.

(c) “Finish grade” is the grade that conforms to the approved site development permit at the conclusion of all grading efforts.

(19) “Grading” is any excavating, filling, removing of the duff layer, or combination thereof.

(20) “Grubbing” is the removal and disposal of all unwanted vegetative material from the earth’s surface including roots, sumps, sod, weeds, buried logs, and other debris.

(21) “Infrastructure improvements” means streets, drainage facilities, utilities, and associated appurtenances typically constructed as part of a development project for the purposes of serving the development.

(22) “Key” means a compacted fill placed in a trench excavated in earth material beneath the toe of a slope.

(23) “Modular block wall” means a wall constructed of manufactured modular wall units acting as a protective facing for an exposed soil face or as a gravity retaining wall. The height of a modular block wall is measured from the base of the bottom row of blocks to the top of the wall as illustrated below.

Figure 15.05.020(23) Modular Block Wall

(24) “Open space” means an area, unoccupied by buildings, roads, or parking areas that has been set aside in perpetuity as a naturally vegetated area. Such open space areas may include native growth protection easements (NGPE), retained vegetated easement areas (RVEA), critical areas, and other tracts of land and easement areas set aside for this purpose.

(25) “Permittee” means the person(s) or entity to whom a site development permit is issued.

(26) “Reinforced fill” or “reinforced soil” means soil fill designed by a geotechnical engineer which includes reinforcement consisting of metal or synthetic materials in bars, strips, grids, or sheets.

(27) “Retaining wall” means a wall designed to resist the lateral displacement of soil or other materials. The height of a cast-in-place concrete retaining wall is measured from the base of the foundation to the top of the wall as illustrated below.

Figure 15.05.020(27) Retaining Wall

(28) “Rockery” or “rock wall” means one or more courses of large rocks stacked near vertical in front of an exposed soil face to protect the soil face from erosion and sloughing. A rockery or rock wall is not a retaining wall. The height of a rock wall is measured from the base of the bottom row of rocks to the top of the wall as illustrated below.

Figure 15.05.020(28) Rockery

(29) “Shorelines” means those lands defined as shorelines of the State in the Shoreline Management Act of 1971. In the City of Woodinville, the Sammamish River and Little Bear Creek are designated as shorelines.

(30) “Site” is any lot or parcel of land or contiguous combination thereof where projects covered by this chapter are performed or permitted.

(31) “Site development permit” or “SDL” means the written permission of the Director to the permittee to proceed with the act of clearing and/or grading within the provisions of this chapter. The site development permit shall include permit documentation, the associated approved plans, and any conditions of approval.

(32) “Site restoration” is the permanent restoration of lands modified under the provisions of this code, typically in the form of the establishment of vegetation and drainage facilities to control the rate and erosive force of stormwater runoff.

(33) “Slope” is an inclined ground surface, the inclination of which is expressed as a ratio of horizontal distance to vertical height or as a percent.

(34) “Terrace” is a relatively level step excavated or constructed in the face of a graded slope surface for drainage and maintenance purposes. (Ord. 635 § 1, 2016)

15.05.030 Applicability.

(1) All clearing and grading activities within the City, regardless of whether a permit is required, shall meet the provisions of this chapter, including performance and restoration requirements and use best management practices to reduce erosion and protect water quality.

(2) All clearing and grading shall comply with the provisions of this municipal code including, but not limited to, the following:

(a) Chapter 12.09 WMC, Street and Construction Standards;

(b) Chapter 21.51 WMC, Critical Areas;

(c) Chapter 21.50 WMC, Tree Protection;

(d) Chapter 21.43 WMC, Landscaping;

(e) Chapter 21.70 WMC, Shoreline Management;

(f) Chapters 13.04 and 13.05 WMC for surface water runoff; and

(g) Requirements from Federal, State, and other local agencies.

(3) When another provision of the Woodinville Municipal Code conflicts with this chapter or when the provisions of this chapter are in conflict, that provision which provides greater environmental protection to critical areas shall apply, unless specifically provided otherwise in this chapter. (Ord. 635 § 1, 2016)

15.05.040 Administration.

(1) Conditions of Approval. The Director may impose conditions on permit approval as needed to mitigate identified project impacts and shall deny permit applications that are inconsistent with the provisions of this chapter. Permit approval shall only be granted if the following criteria are met:

(a) The proposal upholds public health, safety, and welfare;

(b) The proposal does not create long-term grading or drainage impacts on adjoining or downstream properties;

(c) The proposal reflects sound engineering and construction practices;

(d) The proposal protects critical areas pursuant to Chapter 21.51 WMC and shorelines pursuant to Chapter 21.70 WMC; and

(e) The proposal complies with Chapter 13.05 WMC and the adopted King County Surface Water Design Manual.

(2) Inspections. The Director is authorized to make such inspections and take such actions as may be required to enforce the provisions of this chapter, and to require as part of the application materials that the applicant grant permission for such entry and inspections.

(3) Right-of-Entry. Whenever necessary to make an inspection to enforce any of the provisions of this chapter, the Director may enter such property at all reasonable times to inspect the same or perform any duty imposed upon the Director by this chapter. If such property is occupied, the Director shall first present proper credentials and demand entry; and if such property is unoccupied, he or she shall first make a reasonable effort to locate the owner or other persons having charge or control of the property and demand entry. (Ord. 635 § 1, 2016)

15.05.050 Deviations.

(1) The Director shall have the authority to grant a deviation from the provisions of this chapter. Deviations to the provisions of this chapter may be granted, with or without conditions, when the following criteria are met:

(a) The deviation is in the public interest;

(b) The deviation does not negatively impact adjoining properties;

(c) The deviation is based upon sound engineering judgement;

(d) The deviation provides the same or greater level of safety; and

(e) The deviation includes appropriate provisions on maintenance as necessary. (Ord. 635 § 1, 2016)

15.05.060 Site development permit required.

The requirements for a site development permit are set forth in WMC 21.82.110. (Ord. 706 § 14, 2020; Ord. 635 § 1, 2016)

15.05.070 Preliminary grading worksheet.

(1) A preliminary grading worksheet shall be completed and submitted with the project permit application. The worksheet shall be used to make an early determination of the following:

(a) A site development permit is required or if the planned work is exempt;

(b) A geotechnical report is required and whether a short letter-style report, or a longer formal report, is necessary; and

(c) Whether grading plans prepared by a licensed professional (either a civil engineer or engineering geologist) will be required. (Ord. 635 § 1, 2016)

15.05.080 Permit requirements.

Repealed by Ord. 706. (Ord. 635 § 1, 2016)

15.05.090 Expiration of permits and applications.

Repealed by Ord. 706. (Ord. 635 § 1, 2016)

15.05.100 Operating conditions and standards of performance.

(1) Minimize Potential Impacts. All clearing and grading activities shall be conducted so as to minimize potential adverse effects on forested lands, surface water quality and quantity, groundwater recharge, fish and wildlife habitat, adjacent properties, and downstream drainage channels. The applicant shall attempt to prevent impacts and minimize the clearing of naturally occurring vegetation, retain existing soils, and maintain the existing natural hydrological functions of the site.

(2) Stormwater Consistency of Standards. All standards under this code will be consistent with the adopted King County Surface Water Design Manual.

(3) Clearing and Grading and Land Disturbance Limits. When establishing clearing and grading areas, consideration shall be given to minimizing removal of existing trees and minimizing disturbance/compaction of native soils except as needed for building purposes. Clearing and grading areas and any other areas required to preserve critical areas, buffers, native growth protection easements, or tree retention areas shall be delineated on the site plans and the development site.

(a) Prior to beginning land disturbing activities, including clearing and grading, all clearing limits, critical areas and their buffers, and trees that are to be preserved within the construction area shall be clearly marked, both in the field and on the plans, to prevent damage and off-site impacts.

(4) Access. Access roads to sites shall be maintained and located to minimize problems of dust, mud and traffic circulation. Construction vehicle access shall be, whenever feasible, limited to one route. A temporary access road shall be provided at all sites. Access surfaces shall be stabilized to minimize the tracking of sediment onto adjacent roads by utilizing quarry spalls, crushed rock or other equivalent BMPs. Other measures may be required at the discretion of the Director in order to ensure that construction vehicles do not track sediment onto public streets in order to protect storm drains. All approach roads shall be kept clean. Wheel wash or tire baths shall be located on site if the stabilized construction entrance is not effective in preventing sediment from being tracked onto public roads. Sediment shall be removed from roads by shoveling or pickup sweeping and shall be transported to a controlled sediment disposal area. Street washing will be allowed only after sediment is removed in this manner. If sediment is tracked off site, public roads shall be cleaned thoroughly at the end of each day, or more frequently during wet weather. Street wash wastewater shall be controlled by pumping back on site or otherwise be prevented from discharging into systems tributary to State surface waters.

(5) Appearance. The site shall be operated and maintained in a neat and orderly manner, free from junk, trash, or unnecessary debris.

(6) Dust Suppression. Dust from clearing, grading, and other construction activities shall be minimized at all times. Impervious surfaces on or near the construction area shall be swept, vacuumed, or otherwise maintained to suppress dust. Any dust suppressants used shall be approved by the Director. Petrochemical dust suppressants are prohibited.

(7) Fencing and Flagging. Prior to the start of clearing and grading operations, the permittee shall identify all clearing limits with flagging and four-foot-high orange safety fencing or silt fence as approved by the Director:

(a) Along the entire buffer of all critical areas; and

(b) Around all hazards that may exist on the site.

(8) Tree Protection. Tree protection prescribed in Chapter 21.50 WMC shall be installed prior to clearing and grading activities. Fencing shall be installed at the critical root zone of protected trees and shall be four-foot-high chainlink fence. “Tree Protection Area, Entrance Prohibited” signage per Chapter 21.50 WMC shall be installed.

(9) Haul Routes. Prior to the start of clearing and grading operations, the permittee shall identify all proposed haul routes and access points to the site for review and approval by the City.

(10) Hazard Signs. Signs warning of hazardous conditions, if such exist, shall be affixed at locations as required by the Director, prior to the start of clearing and grading operations.

(11) Hours of Operation. Hours of operation shall conform to Chapter 8.08 WMC.

(12) Off-Site Construction. If construction necessitates access, construction, or intrusion onto or across property not under the permittee’s control, then the permittee must provide the City with a copy of a valid construction easement or right-of-entry before the permit can be issued.

(13) Other Pollutants. The permittee must properly handle and dispose of other pollutants that are on site during construction in accordance with the adopted King County Surface Water Design Manual so as to avoid possible health risks or environmental contamination. Direct and indirect discharge of pollutants to the drainage system, critical areas, wetlands, streams, or any other adjacent properties is prohibited. Storage of fuel or other hazardous substances on site is prohibited.

(14) Protect Adjacent and Downstream Property. The permittee shall at all times protect improvements to adjacent private properties and public rights-of-way or easements from damage during clearing and grading operations. The permittee shall restore public improvements damaged by his/her operations to the standards in effect at the time of the issuance of the permit. The permittee is responsible for following the erosion and sediment control measures outlined in the adopted King County Surface Water Design Manual.

(15) Site Security. It shall be the permittee’s responsibility to provide adequate security for the site, as determined by the Director. Should the Director determine that additional measures are required to protect the public, the Director may require the entire site be fenced, gated, and locked and access restricted by the permittee.

(16) Wet Season Clearing and Grading. Clearing and grading shall be prohibited from October 1st to April 30th, the “wet season,” unless otherwise approved by the Director. Building construction, landscaping, road, and utility work may be permitted year-round, so long as such work conforms with all other provisions of this chapter. Clearing and grading may proceed during the wet season upon approval by the Director under the following conditions:

(a) Clearing and grading will only be allowed if, in the opinion of the Director, the site and proposed work pose little or no threat to adjoining properties and downstream drainage facilities;

(b) All sites must implement and maintain effective erosion and sedimentation control. An erosion and sediment control plan shall be prepared at the discretion of the Director that specifically identifies methods of erosion control for wet weather conditions to control erosion/sedimentation, surface water runoff, and safeguard slope stability. In a situation where erosion or sediment is not contained on site, construction activity shall cease immediately and notification of the Director shall be made within 24 hours;

(c) Extraordinary erosion control measures may be required;

(d) Construction of large cuts and fills will not be allowed; and

(e) Failure to comply with adequate TESC measures for the site will warrant a shutdown of the clearing and grading operations until the erosion and sediment control measures are reinstated.

(f) When approval is issued in the dry season (defined as the months of April through September), and work is allowed to continue in the wet season, the City may require additional measures to limit erosion/sedimentation. The Director may prohibit land-disturbing activities during certain days of the wet season. Determinations shall be made on a site-specific basis and evaluation of the following:

(i) Average existing slope on the site with clear delineation of regulated steep slopes.

(ii) Quantity of proposed cut and/or fill.

(iii) Classification of the predominant soils and their erosion and runoff potential.

(iv) Hydraulic connection of the site to features that are sensitive to erosion impacts.

(v) Storm events and periods of heavy precipitation.

(17) Soil Amendments. The duff layer and native topsoil shall be retained in an undisturbed state to the maximum extent practicable. Any duff layer or topsoil removed during grading shall be stockpiled on site in a designated, controlled area not adjacent to public resources and critical areas. The material shall be reapplied to other portions of the site where feasible.

(a) Except as otherwise provided in subsection (17)(b) of this section, areas that have been cleared and graded shall have the soil moisture-holding capacity restored to that of the original undisturbed soil native to the site to the maximum extent practicable. The soil in any area that has been compacted or that has had some or all of the duff layer or underlying topsoil removed shall be amended to mitigate for lost moisture-holding capacity. The amendment shall take place between May 1st and October 1st. The topsoil layer shall be a minimum of eight inches thick, unless the applicant demonstrates that a different thickness will provide conditions equivalent to the soil moisture-holding capacity native to the site. The topsoil layer shall have an organic matter content of between five to 10 percent dry weight and a pH suitable for the proposed landscape plants. When feasible, subsoils below the topsoil layer should be scarified at least four inches with some incorporation of the upper material to avoid stratified layers. Compost used to achieve the required soil organic matter content must meet the definition of “composted materials” in WAC 173-350-220.

(b) This subsection does not apply to areas that:

(i) Are subject to a State surface mine reclamation permit; or

(ii) At project completion are covered by an impervious surface, incorporated into a drainage facility or engineered as structural fill or slope.

(18) Protection of Critical Areas. The function and values of all critical areas, including all stream types, geologically sensitive areas, critical aquifer recharge areas, frequently flooded areas, wetlands, and fish and wildlife conservation areas or habitats, and their critical area buffers located on or adjacent to the site shall be protected from clearing and grading activities that result in sedimentation, erosion, and degradation. Such impacts shall be avoided by installing protection fencing around critical areas and buffers prior to any site disturbance, appropriate use of setbacks, erosion, and sediment control measures and other appropriate best development and management practices consistent with the adopted King County Surface Water Design Manual.

(19) Avoidance of Hazards. Land disturbance activities shall not result in off-site physical damage, nor pose a danger or hazard to life or property. Such activities shall neither contribute to nor create landslides, accelerated soil creep, or settlement of soils.

(20) Dewatering Devices.

(a) Foundation, vault, and trench dewatering water which has similar characteristics to stormwater runoff shall be discharged into a controlled conveyance system prior to discharge to a sediment pond. Channels must be stabilized according to the standards in the adopted King County Surface Water Design Manual.

(b) Clean, nonturbid dewatering water meeting the discharge requirements of the NPDES permit can be discharged to systems tributary to State surface waters, provided the dewatering flow does not cause erosion or flooding of receiving waters. These clean waters should not be routed through stormwater sediment ponds.

(c) Highly turbid or contaminated dewatering water shall be handled separately from stormwater.

(d) Other disposal options, depending on site constraints, may include the following; provided, that the discharge turbidity meets the Washington State Department of Ecology requirements:

(i) Infiltration.

(ii) Transport off site in a vehicle, such as a vacuum flush truck, for legal disposal in a manner that does not pollute State waters.

(iii) On-site treatment using chemical treatment or other suitable treatment technologies.

(iv) Use of a sedimentation bag with outfall to a ditch or swale for small volumes of localized dewatering.

(21) Natural Features and Vegetation Retention. Vegetation, drainage, duff layer, native topsoil, and other natural features of the site should be preserved, and the clearing and grading be performed in a manner that attempts to limit areas of impact to the development area (e.g., structures, roads, utilities, sidewalks, parking, landscaping, etc.). Groundcover and tree disturbance shall be minimized, and root zones shall be protected. Land disturbance activities shall be conducted so as to expose the smallest practical area to erosion for the least possible time. Projects shall be phased to the maximum degree practical and shall take into account seasonal work limitations, to decrease exposed soils and minimize adverse impacts to natural features and vegetation resulting from land disturbance activities.

(22) Slash Removal. Slash from clearing shall preferably be chipped and spread across the site or removed before project completion.

(23) Revegetation. The site shall be revegetated and landscaped as soon as practical, in accordance with a revegetation plan, approved by the Director.

(a) A permanent revegetation plan, utilizing vegetation that is known to have a high natural survival rate, shall be implemented.

(b) Where permanent revegetation measures are not in place within seven days in the dry season and two days in the wet season, the applicant shall provide temporary revegetation or stabilization measures in accordance with the recommendations of the adopted King County Surface Water Design Manual, and maintain such measures in good condition until the permanent revegetation measures are installed and inspected by the City.

(i) Temporary revegetation during the dry season for all disturbed areas of the site (exposed and unworked) that are not covered by permanent improvements such as buildings, parking lots, and decks shall be hydro-seeded and irrigated within seven days until vegetation has been successfully established or the site otherwise revegetated or stabilized using straw mulch, or other approved methods, on an interim basis.

(ii) Temporary revegetation during the wet season for disturbed areas of the site (exposed and unworked) that are not covered by permanent improvements such as buildings, parking lots, and decks shall be hydro-seeded, otherwise revegetated, or stabilized using plastic sheeting or other approved methods, on a temporary basis within two days until vegetation has been successfully established.

(24) Construction Phasing. Development projects shall phase land disturbance to the maximum degree practicable and shall take into account seasonal work limitations in subsection (16) of this section. Construction stormwater pollution prevention plans (SWPPPs) shall indicate land clearing schedules intended to minimize the occurrence and extent of land disturbing activities in the wet season. Each phase of land disturbance shall comply with the requirements of this code.

(25) Maintenance. All temporary and permanent erosion and sediment control devices shall be maintained and repaired as needed. Erosion and sediment control devices that are damaged or not working properly shall be returned to operating condition within 24 hours of identifying they are not working properly or receiving notice from the City, or as otherwise directed by the Director. The contractor shall:

(a) Regularly inspect (weekly and within 24 hours after any runoff producing storm event during the dry season, and daily, including on weekends, during the wet season and during rainfall events) all temporary and permanent erosion and sedimentation BMPs and maintain them per the development standards so that they function as intended until the site has been permanently stabilized, and the potential for on-site erosion has passed. Inlets should be inspected weekly at a minimum and daily during storm events. Inlet protection devices should be cleaned or removed and replaced when sediment has filled one-third of the available storage (unless a different standard is specified by the product manufacturer).

(b) Return any BMPs that are not functioning properly to normal operating conditions within 24 hours of receiving notice from the City. BMPs that must be addressed include: critical area buffers/setbacks, stormwater/pollutant protection, natural feature preservation/vegetation retention, avoidance of hazards, revegetation, erosion and sediment control, and permanent retention/detention facilities. The responsibility for maintaining site stability and maintenance objectives for buffer vegetation and permanent erosion, sedimentation, and runoff control structures for the original permit requirements is the responsibility of the property owner once the work is complete and final restoration measures have been installed as per the plans or approved permit requirements.

(26) Site-Specific Requirements. Additional, site-specific requirements may be established after a site visit by the City. These requirements shall be based on specific site conditions and are limited to additional temporary erosion and sedimentation control and the mitigation of hazardous or potentially hazardous conditions that pose a threat off site or habitat preservation.

(27) Project Management.

(a) Construction site operators shall maintain, update and implement their SWPPP as required in the adopted King County Surface Water Design Manual. Construction site operators shall modify their SWPPP whenever there is a change in design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the State.

(b) The SWPPP shall be modified whenever there is a significant change in the design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the State.

(c) The SWPPP shall be modified if, during inspections or investigations conducted by the owner/operator or the applicable local or State regulatory authority, it is determined that the SWPPP is ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. The SWPPP shall be modified as necessary to include additional or modified BMPs designed to correct problems identified. Revisions to the SWPPP shall be completed within seven calendar days following the inspection. (Ord. 635 § 1, 2016)

15.05.110 Grading – Land development projects.

(1) For all land development projects such as subdivisions and short subdivisions, the permittee shall, after being issued the proper permits, clear and grade the property and install infrastructure improvements. Individual lots shall be cleared and graded as follows:

(a) Individual lots shall be cleared and graded as part of the overall project mass grading and construction of infrastructure. The individual lots shall be graded to accept the expected buildings and driveways. All lots shall be designed and constructed with due regard to the natural topography:

(i) Walls and slopes proposed as a means of grade separation between lots shall be constructed as part of the mass grading phase of the project and shall be constructed entirely on the downhill lot.

(ii) If lots are expected to be constructed for a daylight basement type building, the lot shall be prepared as near as possible for such a building, by grading a terrace at some distance from the street. The excess material from the terrace shall be hauled off site or utilized as fill, if suitable elsewhere on the project.

(b) The land developer may elect to defer clearing and grading of individual lots and only construct the infrastructure for the project. Clearing and grading of the deferred lots shall be in accordance with applicable criteria set forth in WMC 15.05.120. (Ord. 635 § 1, 2016)

15.05.120 Grading – Individual lots.

Individual lots may be cleared and graded with the following restrictions:

(1) Grading across property boundaries will only be allowed if a separate site development is issued for the grading activity for each affected lot.

(2) Any grading of the property and individual lots shall generally conform to the natural topography of the property and adjacent properties, and all provisions of this chapter. (Ord. 635 § 1, 2016)

15.05.130 Drainage.

All clearing and grading operations shall take all necessary precautions, through the use of best management practices, to control drainage within the site and off site to avoid damage to adjoining properties and drainage facilities and prevent impacts to water quality:

(1) In addition to the measures in this and the adopted King County Surface Water Design Manual, the Director may impose the following erosion control measures, or other additional measures, as appropriate for the project:

(a) Flow control facilities shall be installed for the duration of the clearing and grading operations in accordance with the adopted King County Surface Water Design Manual.

(b) Cut and fill slopes shall be provided with subsurface drainage as necessary for stability.

(c) All building lots shall be graded and prepared such that all roof, yard, wall, slope, driveway, and footing drains can be connected directly by gravity to the project’s drainage system. Discharge to an alternate location may be allowed only with prior approval of the Director, and appropriate easements from affected downstream property owners. (Ord. 635 § 1, 2016)

15.05.140 Slopes.

Slopes shall be constructed with due regard for drainage, access, maintenance, impacts to adjacent property, and aesthetics. Constructed slopes shall comply with all applicable codes and standards and the following criteria:

(1) Cut and fill surfaces shall be no steeper than is safe for the intended use. Slopes shall be constructed no steeper than 2H:1V. Steeper slopes may be constructed upon approval of the Director and the City’s concurrence with the recommendations of a geotechnical engineer, for those areas lying outside the building envelope. In addition, the following standards shall apply to cut and fill slopes:

(a) Clearing and grading on slopes shall meet any critical areas standards set forth in Chapter 21.51 WMC.

(b) Intercept any groundwater, subsurface water, or surface water drainage encountered on a cut slope and discharge it at a location approved by the Director. Off-site stormwater (run-on) or groundwater shall be diverted away from slopes and undisturbed areas with interceptor dikes, pipes and/or swales. Off-site stormwater should be managed separately from stormwater generated on the site.

(c) Excavated material shall be placed in a manner consistent with safety and space considerations.

(d) Check dams shall be placed at regular intervals within constructed channels that are cut down a slope.

(e) At the top of slopes, collect drainage in pipe slope drains or protected channels to prevent erosion. Temporary pipe slope drains shall handle the expected peak 10-minute flow velocity from a Type 1A, 10-year, 24-hour frequency storm for the developed condition. Alternatively, the 10-year, one-hour flow rate predicted by an approved continuous runoff model, increased by a factor of 1.6, may be used. The hydrologic analysis shall use the existing land cover condition for predicting flow rates from tributary areas outside the project limits. For tributary areas on the project site, the analysis shall use the temporary or permanent project land cover condition, whichever will produce the highest flow rates. Bare soil areas should be modeled as “landscaped area.”

(2) Existing slopes shall not be oversteepened beyond the criteria in subsection (1) of this section by placing fill or by constructing a fill wall near the top of the slope.

(3) If building sites are prepared by constructing slopes near the property line, the slope between building sites shall be constructed during the mass grading of the project, entirely on one lot.

(4) Drainage at the top and toe of any slope shall be appropriately collected and discharged:

(a) The ground surface above a slope shall be graded to direct surface runoff to an appropriate collection point. Water shall not be allowed to discharge over the top of a slope.

(b) Slopes shall not be constructed in a location or manner in which surface runoff and debris are permitted to drain onto an adjacent property.

(c) Slopes shall be designed and protected to minimize erosion.

(d) Terraces at least 10 feet in width shall be sloped away from the face of a slope and shall be established at not more than 25-foot vertical intervals to control surface drainage and debris. Swales or ditches on terraces shall have a maximum gradient of five percent.

(5) Setbacks. The tops and the toes of cut and fill slopes shall be set back from property boundaries as far as necessary, as determined by a geotechnical engineer for safety of the adjacent properties and to prevent damage resulting from water runoff or erosion. The tops and toes of cut and fill slopes shall be set back from structures as far as is necessary, as determined by a geotechnical engineer for adequacy of foundation support and to prevent damage as a result of water runoff or erosion. Slope setbacks shall be as follows:

(a) The top of slopes shall be no nearer the property line than five horizontal feet or one-fifth the vertical height of the slope, whichever is greater.

(b) The toe of fill slopes shall be no nearer the property line than five horizontal feet or one-half the vertical height of the slope, whichever is greater.

(c) Rockeries shall be set back a minimum distance of 20 feet to allow for future maintenance. (Ord. 635 § 1, 2016)

15.05.150 Fill.

(1) Preparation of Ground. The ground surface shall be prepared to receive fill by removing vegetation and unsuitable soil and material such as concrete rubble, topsoil, tree stumps, and brush. Where slopes receiving fill are steeper than five horizontal to one vertical, the fill material shall be benched into adequate bearing nonorganic soil.

(2) Fill Material. All on-site materials used as fill on the site shall conform to the specifications identified in the approved soils report.

(3) Compaction. All engineered fill material shall be mechanically compacted as determined by the design engineer or per the permit requirements as determined by the Director. At a minimum, all fills or embankments shall be compacted to a minimum density of 90 percent of Modified Proctor (ASTM D1557) unless different requirements are required to meet low impact development (LID) requirements as determined by the Director. (Ord. 635 § 1, 2016)

15.05.160 Rock and retaining walls.

Walls shall be designed and constructed with due regard for drainage, access, maintenance, impacts to adjacent property, and aesthetics. All walls shall be constructed in accordance with all applicable codes and standards and the following criteria:

(1) Rockeries may be used for erosion protection of cut or fill slopes. The primary function of a rock wall is to protect the slope face from soil erosion and sloughing. Rockeries may not be used to support building foundation loads or fills that support building foundation loads.

(2) Any wall supporting a surcharge or over four feet in height shall require a separate building permit.

(3) All walls shall be provided with a wall drainage system. The wall drainage system shall discharge at an appropriate location:

(a) Wall drains shall be connected to the storm drainage stub provided for the lot, if possible.

(b) Wall drains shall not discharge onto a downhill property, unless the downhill property is a vegetated area that has been set aside as permanent open space or critical area, with approval from the City and affected property owner.

(c) Wall drains shall not discharge onto a steep slope as defined by WMC 21.51.250(2)(b)(vi) or areas susceptible to erosion.

(d) The area above the wall shall be graded to channel water in a direction parallel to the face of the wall until the water can be collected in a pipe or drain, or discharged at an appropriate location.

(4) All walls parallel to a building shall be set back from the building a minimum of five feet. This setback applies to the horizontal space between the wall and the building as measured from the front face of a wall or the cut slope for a wall and the face of the building.

(5) Walls existing at the time of the ordinance codified in this chapter, if constructed under a valid permit, may be repaired or replaced to their original height.

(6) Walls shall not support earth, walls, or other structures on an adjacent property.

(7) Walls taller than eight feet must be screened if visible from adjacent property or a public right-of-way.

(8) Walls shall not be located in separate tracts or public rights-of-way for the purposes of circumventing the provisions of this chapter.

(9) Walls shall not be stacked wherein a lower wall is supporting an upper wall unless the lower wall is designed to do so. Minimum horizontal spacing between rock or retaining walls, as measured from face to face, shall be no less than the thickness of the lower wall plus the height of the lower wall.

(10) When preparing a grading plan and designing a driveway or private road, use of a retaining wall to support the roadway shall be considered only after other design options are exhausted. When a roadway must be supported by a retaining wall, the City may require additional building setbacks, easements or other restrictions and provisions to allow proper maintenance of the wall.

(11) Walls shall not be located or constructed so as to impede travel on the public right-of-way or impinge on it.

(12) The area above the wall shall be designed and constructed to prevent surface water and debris from flowing over the top of the wall, and to allow for access and maintenance to the area above the wall. The area between the wall and the building shall be graded no steeper than five percent, perpendicular to the face of the wall, for a distance of five feet, for that area located within five feet of the building.

(13) Walls shall not be used to break up a slope or to circumvent the definition of or the restrictions for steep slope hazard areas as described in Chapter 21.51 WMC.

(14) Walls constructed between lots shall be constructed entirely on the downhill side of the property line entirely on one lot, including the wall drainage system. (Ord. 635 § 1, 2016)

15.05.170 Utilities.

The installation of utilities (e.g., water, sewer, and drainage pipes) across steep topography on single-family lots greatly reduces the amount of buildable space on the lot. Cutting, filling or constructing walls within storm, water, and sanitary sewer easements is prohibited, unless specific written approval from the utility owner is provided. It shall be the permittee’s responsibility to obtain said approval, and provide a copy to the City. (Ord. 635 § 1, 2016)

15.05.180 Driveways – Design.

Lots shall be prepared to accept a driveway meeting all applicable public works standards regarding width and slope. Where a lot fronts on a steep roadway, the driveway shall be narrowed and/or lengthened in order to meet the standards regarding driveway slope. Where increased driveway lengths are required, subdivisions and short plats shall contain a note on the face of the plat indicating those lots affected, and to what degree the driveways are to be lengthened. (Ord. 635 § 1, 2016)

15.05.190 Inspections.

(1) All projects with a site development permit are subject to City inspections to ensure compliance with the permit, and that adequate control is being exercised by the contractor, civil engineer, and geotechnical engineer. The City shall specify the general stages of work when inspection is required and may require inspection and testing by an approved testing agency, to be paid by the permittee.

(2) The permittee shall employ qualified professionals to perform inspections of the site grading when using an approved testing agency. (Ord. 635 § 1, 2016)

15.05.200 Final approval.

(1) The Director shall give final approval to the clearing and grading operations once all the work is completed per the permit. The following must be completed, as a minimum, prior to final approval:

(a) All clearing and grading must be complete;

(b) The site shall be permanently stabilized, temporary erosion control measures removed, and storm drainage control facilities constructed and operational;

(c) The site shall be in a neat and orderly manner, free from junk, trash, debris, equipment, stockpiles and other construction materials;

(d) All required inspection, observation, and testing summary reports, as-built drawings, and other documentation as required by the permit shall be submitted and approved by the City;

(e) The site shall be free of hazards; and

(f) All disputes regarding property damage caused by the clearing and grading operations shall be resolved to the satisfaction of the Director or judicial authority.

(2) The City shall not issue final approval for any development proposal or issue a certificate of occupancy or final building inspection for property which has not received final approval for the clearing and grading operations. (Ord. 635 § 1, 2016)

15.05.210 Stop work order/permit revocation.

(1) Permit Suspension/Revocation. The Director may suspend work or revoke a site development permit, as appropriate, whenever:

(a) The work is not authorized by a valid permit;

(b) The permittee requests such revocation or suspension;

(c) The work does not proceed in accordance with the plans, as approved, or is not in compliance with the requirements of this chapter or other City ordinances;

(d) Entry upon the property for the purposes of investigation or inspection has been denied;

(e) The permittee has made a misrepresentation of a material fact in applying for such permit;

(f) The progress of the work indicates that the plan is or will be inadequate to protect the public, the adjoining property, the street, protected areas, the drainage system, or other utilities;

(g) The required project security has expired or has been expended to the point that it no longer provides assurance of completion of the project in compliance with the permit approval; or

(h) The permit has not been acted upon or extended within the time allowed pursuant to WMC 15.05.090.

(2) Stop Work Order. The Director shall issue the permittee a written stop work order specifying the nature of the violation or problem which must be remedied prior to resuming other work on the project. If the permittee does not comply with the order within the time specified, the Director, as an alternative to other remedies, may enter the project site and perform the required work. All costs incurred by the City in performing such work shall be drawn against the surety posted by the permittee to ensure the enforcement of the provisions of the permit. In the absence of sufficient surety, the City may place a lien against the property in the amount of the funds expended to perform the required work.

(3) Restoration. Violators of this chapter, or of a permit issued hereunder, shall be responsible for restoring unlawfully damaged areas in conformance with a restoration plan, approved by the Director, which provides for repair of any environmental and property damage, and restoration of the site; and which results in a site condition that, to the greatest extent practical, equals the site condition that would have existed in the absence of the violation(s).

(4) Prohibition of Further Approvals. The City shall not accept, process, or approve any application for development proposal, or issue a certificate of occupancy or final building inspection for property on which a violation of this chapter has occurred until the violation is cured by restoration or other means acceptable to the Director and by payment of any penalty imposed for the violation. (Ord. 635 § 1, 2016)

15.05.220 Forest practices.

(1) Class IV Forest Practice. Under a Class IV forest practice, all clearing not otherwise exempted under this chapter shall be subject to the requirements of this chapter. All such clearing shall be subject to the State Environmental Policy Act, Chapter 43.21C RCW, and the City shall accept or assume lead agency status. The review of the Class IV application shall be consolidated with the review of the associated development permit or approval. Clearing independent of permit or approval shall require a separate site development permit pursuant to this chapter. The City will also combine its SEPA review of Class IV forest practices and City permits.

(2) Development applications on lands cleared or graded pursuant to a Class I, II, III or IV special forest practice as defined in Chapter 76.09 RCW, or cleared or graded without forest practices or City authorization, shall be denied for a period of six years unless the applicant demonstrates that the clearing was consistent with requirements of this chapter or the applicant adequately restores the site. Restoration shall include, but is not limited to, reforestation, erosion control, critical areas enhancement and restoration, surface water management controls, and compliance with other applicable City and State regulations. Administrative rules may set out further details as to how restoration is accomplished and when it will be deemed sufficient. (Ord. 635 § 1, 2016)

15.05.230 Violations – Penalties.

Repealed by Ord. 685. (Ord. 635 § 1, 2016)