Chapter 13.20 STORM WATER MANAGEMENT

There is adopted, and by this reference made a part of this chapter as though fully set forth herein at length, that certain document known as the technical manual adopted by the Department of Ecology, as and for the storm water control standards of the town, one copy of which is on file in the office of the town clerk/treasurer. (Ord. 311 § 1, 1995).

13.20.010 Findings of fact.

The Index town council hereby finds that:

(A) Storm water pollution is a problem associated with land utilization and development and the common occurrence of potential pollutants such as fertilizers, petroleum products, pet wastes and numerous others.

Land utilization and development is also known to increase both the volume and duration of peak flows. The resulting erosion, scouring, and deposition of sediment affect the ecological balance in the stream.

Sedimentation and storm water pollution cause diversity of species to decrease and allows more tolerant (and usually less desirable) species to remain.

Storm water pollution can cause or contribute to closure of swimming beaches and other restrictions on public use of the waters within Index, Washington.

(B) An expanding population and increased development of land may lead to: water quality degradation through discharge of nutrients, metals, oil and grease, toxic materials, and other detrimental substances; drainage and storm and surface water runoff problems within Index; and safety hazards to both lives and property posed by uncontrolled water runoff on streets and highways.

(C) Continuation of present storm water management practices, to the extent that they exist, will lead to water quality degradation, erosion, property damage, and endanger the health and safety of the inhabitants of Index.

(D) In the future such problems and dangers will be reduced or avoided if existing properties and future developers, both private and public, provide for storm water quality and quantity controls.

(E) Storm water quality and quantity controls can be achieved when land is developed or redeveloped by implementing appropriate best management practices (BMPs).

(F) Best management practices can be expected to perform as intended only when properly designed, constructed and maintained. (Ord. 312 § 1.1, 1995).

13.20.020 Need.

The Index town council finds that this chapter is necessary in order to:

(A) Maintain or eliminate water quality degradation;

(B) Prevent erosion and sedimentation in creeks, streams, ponds, lakes and other water bodies;

(C) Protect property owners adjacent to existing and developing lands from increased runoff rates which could cause erosion of abutting property;

(D) Preserve and enhance the suitability of waters for contact recreation, fishing, and other beneficial uses;

(E) Preserve and enhance the aesthetic quality of the water;

(F) Promote sound development policies which respect and preserve Index surface water, ground water and sediment;

(G) Ensure the safety of Index roads and rights-of-way;

(H) Decrease storm water-related damage to public and private property from existing and future runoff;

(I) To protect the health, safety, and welfare of the inhabitants of Index. (Ord. 312 § 1.2, 1995).

13.20.030 Purpose.

(A) The provisions of this chapter are intended to guide and advise all who conduct new development or redevelopment within Index. The provisions of this chapter establish the minimum level of compliance which must be met to permit property to be developed or redeveloped within Index.

(B) It is the purpose of this chapter to:

(1) Minimize water quality degradation and sedimentation in streams, ponds, wetlands, and other water bodies;

(2) Minimize the impact of increased runoff, erosion, and sedimentation caused by land development and maintenance practices;

(3) Maintain and protect ground water resources;

(4) Minimize adverse impacts of alterations on ground and surface water quantities, locations and flow patterns;

(5) Decrease potential landslide, flood and erosion damage to public and private property;

(6) Promote site planning and construction practices that are consistent with natural topographical, vegetational and hydrological conditions;

(7) Maintain and protect the Index storm water management infrastructure and those downstream;

(8) Provide a means of regulating clearing and grading of private and public land while minimizing water quality impacts in order to protect public health and safety; and

(9) Provide minimum development regulations and construction procedures which will preserve, replace or enhance, to the maximum extent practicable, existing vegetation to preserve and enhance the natural qualities of lands, wetlands, and water bodies. (Ord. 312 § 1.3, 1995).

13.20.040 Definitions.

For the purpose of this chapter, the following definitions shall apply:

(1) “American Public Works Association” or “APWA” means the adopted edition of the Washington State Chapter of the American Public Works Association.

(2) “Approval” means the proposed work or completed work conforms to this chapter in the opinion of the administrator.

(3) “As-graded” means the extent of surface conditions on completion of grading.

(4) “Basin plan” means a plan and all implementing regulations and procedures including but not limited to land use management adopted by ordinance for managing surface and storm water management facilities and features within individual subbasins.

(5) “Bedrock” means the more or less solid rock in place either on or beneath the surface of the earth. It may be soft, medium, or hard and have a smooth or irregular surface.

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

(7) “Best management practices” or “BMPs” means physical, structural, and/or managerial practices that, when used singly or in combination, prevent or reduce pollution of water. BMPs are listed and described in the manual.

(8) “Civil engineer” means a professional engineer licensed in the state of Washington in civil engineering who is experienced and knowledgeable in the practice of soils engineering.

(9) “Civil engineering” means the application of the knowledge of the forces of nature, principles of mechanics and the properties of materials to the evaluation, design and construction of civil works for the beneficial uses of mankind.

(10) “Clearing” means the destruction and removal of vegetation by manual or mechanical methods.

(11) “Compaction” means densification of a fill by mechanical means.

(12) “Critical areas” means, at a minimum, areas which include wetlands, frequently flooded areas, geologically hazardous areas, including unstable slopes, and associated areas and ecosystems.

(13) “Design storm” means a prescribed hyetograph and total precipitation amount (for a specific duration recurrence frequency) used to estimate runoff for as hypothetical storm of interest or concern for the purpose of analyzing existing drainage, designing new drainage facilities or assessing other impacts of a proposed project on the flow of surface water.

(14) “Detention” means the release of storm water runoff from the site at a slower rate that it is collected by the storm water facility system, the difference being held in temporary storage.

(15) “Detention facility” means an above or below ground facility, such as a pond or tank, that temporarily stores storm water runoff and subsequently releases it at a slower rate than it is collected by the drainage facility system. There is little or no infiltration of stored storm water.

(16) “Drainage basin” means a geographic and hydrologic subunit of a watershed.

(17) “Earth material” means any rock, natural soil or fill and/or any combination thereof.

(18) “Ecology” means the Washington State Department of Ecology.

(19) “Engineering geologist” means a geologist experienced and knowledgeable in engineering geology.

(20) “Engineering geology” means the application of geologic knowledge and principles in the investigation and evaluation of naturally occurring rock and soil for use in the design of civil works.

(21) “Erosion” means the wearing away of the land surface by running water, wind, ice, or other geological agents, including such processes as gravitational creep, detachment and movement of soil or rock fragments by water, wind, ice, or gravity.

(22) “Excavation” means the mechanical removal of earth material.

(23) “Existing site conditions” means:

(a) For developed sites with storm water facilities that have been constructed to meet the standards in the minimum requirements of the manual, “existing site conditions” shall mean the existing conditions on the site.

(b) For developed sites that do not have storm water facilities that meet the minimum requirements, “existing site conditions” shall mean the conditions that existed prior to local government adoption of a storm water management program. If in question, the existing site conditions shall be documented by aerial photograph records, or other appropriate means.

(c) For all sites in water quality sensitive areas as identified under minimum requirements no. 7, Water quality sensitive areas, “existing site conditions” shall mean undisturbed forest for the purpose of calculating runoff characteristics.

(d) For all undeveloped sites outside of water quality sensitive areas, “existing site conditions” shall mean the existing conditions of the site.

(24) “Experimental BMP” means a BMP that has not been tested and evaluated by the Department of Ecology in collaboration with local governments and technical experts.

(25) “Fill” means a deposit of earth material placed by artificial means.

(26) “Forest practice” means any activity conducted on or directly pertaining to forest land and relating to growing, harvesting, or processing timber, including but not limited to: road or trail construction, final and intermediate harvesting, precommercial thinning, reforestation, fertilization, prevention and suppression of diseases and insects, salvage of trees, and brush control.

(27) “Frequently flooded areas” means the 100-year floodplain designations of the Federal Emergency Management Agency and the National Flood Insurance Program.

(28) “Geologically hazardous areas” means areas that because of their susceptibility to erosion, sliding, earthquake or other geological events, are not suited to the siting of commercial, residential, or industrial development consistent with public health or safety concerns.

(29) “Grade” means the slope of a road, channel or natural ground; the finished surface of a canal bed, roadbed, top of embankment, or bottom of excavation; any surface prepared for the support of construction such as paving or the laying of a conduit.

(a) “Existing grade” means the grade prior to grading.

(b) “Rough grade” means the stage at which the grade approximately conforms to the approval plan.

(30) “Gradient terrace” means an earth embankment or a ridge-and-channel constructed with suitable spacing and an acceptable grade to reduce erosion damage by intercepting surface runoff and conducting it to a stable outlet at a stable nonerosive velocity.

(31) “(To) grade” means to finish the surface of a canal bed, roadbed, top of embankment or bottom of excavation.

(32) “Ground water” means water in a saturated zone or stratum beneath the surface of land or a surface water body.

(33) “Hydroperiod” means the seasonal occurrence of flooding and/or soil saturation; it encompasses depth, frequency, duration, and seasonal pattern of inundation.

(34) “Impervious surface” means a hard surface area which either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development, and/or a hard surface area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Common impervious surfaces include, but are not limited to, roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving, gravel roads, packed earthen materials, and oiled, macadam or other surfaces which similarly impede the natural infiltration of storm water. Open, uncovered retention/detention facilities shall not be considered as impervious surfaces.

(35) “Illicit discharge” means all non-storm water discharges to storm water drainage systems that cause or contribute to a violation of state water quality, sediment quality or ground water quality standards, including but not limited to interior flow drains, car washing and graywater systems.

(36) “Interflow” means that portion of rainfall that infiltrates into the soil and moves laterally through the upper soil horizons until intercepted by a stream channel or until it returns to the surface for example, in a wetland, spring or seep.

(37) “Land disturbing activity” means any activity that results in a change in the existing soil cover (both vegetative and nonvegetative) and/or the existing soil topography. Land disturbing activities include, but are not limited to, demolition, construction, clearing, grading, filling, and excavation.

(38) “Large parcel erosion and sediment control plan” or “large parcel ESC plan” means a plan to implement BMPs to control pollution generated during land disturbing activity.

(39) “Mitigation” means, in the following order of preference:

(a) Avoiding the impact altogether by not taking certain action or part of an action;

(b) Minimizing impacts by limiting the degree or magnitude of the action and its implementation, by using appropriate technology, or by taking affirmative steps to avoid or reduce impacts;

(d) Reducing or eliminating the impact over time by preservation and maintenance operations during the life of the action; and

(e) Compensation for the impact by replacing, enhancing, or providing substitute resources or environments.

(40) “Natural location” means the location of those channels and other non-manmade conveyance systems as defined by the first documented topographic contours existing for the subject property, either from maps or photographs, or such other means as appropriate.

(41) “New development” means the following activities: land disturbing activities, structural development, including construction, installation or expansion of a building or other structure; creation of impervious surfaces; and subdivision and short subdivision of land as defined in RCW 58.17.020.

(42) “Permanent storm water quality control (PSQC) plan” means a plan which includes permanent BMPs for the control of pollution from storm water runoff after construction and/or land disturbing activity has been completed.

(43) “Person” means any individual, partnership, corporation, association, organization, cooperative, public or municipal corporation, agency of the state, or local government unit, however designated.

(44) “Pollution” means contamination or other alteration of the physical, chemical, or biological properties, of waters of the state, including change in temperature, taste, color, turbidity, or odor of the waters, or such discharge of any liquid, gaseous, solid, radioactive or other substance into any waters of the state as will or is likely to create a nuisance or render such waters harmful, detrimental or injurious to the public health, safety or welfare, or to domestic, commercial, recreational, or other legitimate beneficial uses, or to livestock, wild animals, birds, fish or other aquatic life.

(45) “Redevelopment” means, on an already developed site, the creation or addition of impervious surfaces, structural development including construction, installation or expansion of a building or other structure, and/or replacement of impervious surface that is not part of a routine maintenance activity, and land disturbing activities associated with structural or impervious redevelopment.

(46) “Regional retention/detention system” means a storm water quality control structure designed to correct existing excess surface water runoff problems of a basin or subbasin. The area downstream has been previously identified as having existing or predicted significant and regional flooding and/or erosion problems. This term is also used when a detention facility is used to detain storm water runoff from a number of different businesses, or areas within a catchment.

(47) “Retention/detention facility (R/D)” means a type of drainage facility designed either to hold water for a considerable length of time and then release it by evaporation, plant transpiration, and/or infiltration into the ground; or to hold surface and storm water runoff for a short period of time and then release it to the surface and storm water management system.

(48) “Site” means the portion of a piece of property which is directly subject to development.

(49) “Slope” means the degree of deviation of a surface from the horizontal, measured as a numerical ratio, percent, or in degrees. Expressed as a ration, the first number is the horizontal distance (run) and the second if the vertical distance (rise), as 2:1. A 2:1 slope is a 50 percent slope. Expressed in degrees, the slope is the angle from the horizontal plane, with a 90-degree slope being vertical (maximum) and 45-degree being a 1:1 or 100 percent slope.

(50) “Small parcel erosion and sediment control plan” or “small parcel ESC plan” means a plan for small sites to implement temporary BMPs to control pollution generated during the construction phase only, primarily erosion and sediment.

(51) “Soil” means the unconsolidated mineral and organic material on the immediate surface of the earth that serves as a natural medium for the growth of land plants.

(52) “Source control BMP” means a BMP that is intended to prevent pollutants from entering storm water. A few examples of source control BMPs are erosion control practices, maintenance of storm water facilities, and constructing roofs over storage and working areas.

(53) “Storm water” means that portion of precipitation that does not naturally percolate in to the ground or evaporate, but flows via overland flow, interflow, channels or pipes into a defined surface water channel, or a constructed infiltration facility.

(54) “Storm water drainage system” means constructed and natural features which function together as a system to collect, convey, channel, hold, inhibit, retain, detain, infiltrate, divert, treat or filter storm water.

(55) “Storm water facility” means a constructed component of a storm water drainage system, designed or constructed to perform a particular function, or multiple functions. Storm water facilities include but are not limited to: ditches, culverts, street gutters, detention or retention basins, and catchbasins.

(56) “Storm water management manual” or “manual” means the manual adopted by reference and prepared by Ecology that contains BMPs to prevent or reduce pollution.

(57) “Storm water site plan” means a plan which includes an erosion and sediment control (ESC) plan and/or a permanent storm water quality control plan (PSQCP). For small sites, this plan is the equivalent of a small parcel erosion control plan. Guidance on preparing a storm water site plan is contained in the manual.

(58) “Toe of slope” means a point or line of slope in an excavation or cut where the lower surface changes to horizontal or meets the existing ground slope.

(59) “Top of slope” means a point or line on the upper surface of a slope where it changes to horizontal or meets the original surface.

(60) “Treatment BMP” means a BMP that is intended to remove pollutants from storm water, a few examples of treatment BMPs are detention ponds, oil/water separators, biofiltration swales and constructed wetlands.

(61) “Unstable slopes” means those sloping areas of land which have in the past exhibited, are currently exhibiting, or will likely in the future exhibit mass movement of earth.

(62) “Water body” means surface water including rivers, streams, and wetlands.

(63) “Watershed” means a geographic region within which water drains into a particular river, stream, or body of water as identified and numbered by the State of Washington Water Resource Inventory Areas (WRIAs) as defined in Chapter 173-500 WAC.

(64) “Wetlands” means those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marches, bogs, and similar areas. This includes wetlands created, restored or enhanced as part of a mitigation procedure. This does not include constructed wetlands or the following surface waters of the state intentionally constructed from sites that are not wetlands: irrigation and drainage ditches, farm ponds, and landscape amenities.

(65) “Vegetation” means all organic plant life on the surface of the earth. (Ord. 312 § 2, 1995).

13.20.050 Abrogation and greater restrictions.

It is not intended that this chapter repeal, abrogate, or impair any existing regulations, easements, covenants, or dead restrictions. However, where this chapter imposes greater restrictions, the provisions of this chapter shall prevail. (Ord. 312 § 3.1, 1995).

13.20.060 Interpretation.

The provisions of this chapter shall be held to be minimum requirements in their interpretation and application and shall be liberally construed to serve the purposes of this chapter. (Ord. 312 § 3.2, 1995).

13.20.070 Conflicts.

When any provision of any other chapter of the town of Index conflicts with this chapter, that which provides more environmental protection shall apply unless specifically provided otherwise in this chapter. (Ord. 312 § 3.3, 1995).

13.20.080 Applicability.

(A) The town of Index is authorized to adopt written procedures for the purpose of carrying out the provisions of this chapter. Prior to fulfilling the requirements of this chapter, the town of Index shall not grant any approval or permission to conduct a regulated activity including but not limited to the following: building permit, commercial or residential; binding site plan; conditional use permit; franchise right-of-way construction permit; grading and clearing permit; master plan development; planned unit development; right-of-way permit; shoreline substantial development permit; shoreline variance; shoreline conditional use permit; shoreline environmental redesignation; unclassified use permit; variance; zone reclassification; subdivision; short subdivision; special use permit; utility and other use permit; zone reclassification; or any subsequently adopted permit or required approval not expressly exempted by this chapter.

(B) Regulated activities shall be conducted only after the town of Index approves a storm water site plan which includes one or more of the following as required by this chapter:

(1) Small parcel erosion and sediment control plan;

(2) Large parcel erosion and sediment control plan;

(3) Permanent storm water quality control (PSQC) plan. (Ord. 312 § 4, 1995).

13.20.090 Regulated activities.

Consistent with the minimum requirements contained in this chapter, the town of Index shall approve or disapprove the following activities, unless exempted in Section 13.20.100 of this chapter:

(A) New Development.

(1) Land disturbing activities;

(2) Structural development, including construction; installation or expansion of a building or other structure;

(3) Creation of impervious surfaces;

(4) Class IV general forest practices that are conversions from timber land to other uses;

(5) Subdivision, short subdivision and building site plans, as defined in RCW 58.17.020.

(B) Redevelopment. On an already developed site, the creation or addition of impervious surfaces, structural development including construction, installation or expansion of a building or other structure, land disturbing activity, and land disturbing activities associated with structural or impervious redevelopment. (Ord. 312 § 5.1, 1995).

13.20.100 Exemptions.

(A) Commercial agriculture and forest practices regulated under Title 222 WAC, except for Class IV general forest practices that are conversions from timber land to other uses, are exempt from the provisions of this chapter.

(B) Development undertaken by the Washington State Department of Transportation in state highway right-of-way is regulated by Chapter 173-270 WAC, the Puget Sound Highway Runoff Program.

(C) All other new development and redevelopment is subject to the minimum requirements of this chapter. (Ord. 312 § 5.2, 1995).

13.20.110 Storm water management manual adopted.

The latest edition of Ecology’s storm water management manual is hereby adopted by reference and is hereafter referred to as the manual. (Ord. 312 § 6.1, 1995).

13.20.120 Storm water best management practices (BMPs).

(A) General. BMPs shall be used to control pollution from storm water. BMPs shall be used to comply with the standards of this chapter. BMPs are in the manual.

(B) Experimental BMPs. In those instances where appropriate BMPs are not in the manual, experimental BMPs should be considered. Experimental BMPs are encouraged as a means of solving problems in a manner not addressed by the manual in an effort to improve storm water quality technology. Experimental BMPs must be approved in accordance with the approval process outlined in the manual. (Ord. 312 § 6.2, 1995).

13.20.130 Illicit discharges.

Illicit discharges to storm water drainage systems are prohibited. (Ord. 312 § 6.3, 1995).

13.20.140 Small parcel minimum requirements.

(A) The following new development shall be required to control erosion and sediment during construction, to permanently stabilize soil exposed during construction, and to comply with small parcel requirements 1 through 5 in Sections 13.20.150 through 13.20.190:

(1) Individual, detached, single-family residences and duplexes.

(2) Creation or addition of less than 5,000 square feet of impervious surface area.

(3) Land disturbing activities of less than one acre.

(B) Compliance shall be demonstrated through the implementation of an approved small parcel erosion and sediment control plan. (Ord. 312 § 7.1, 1995).

13.20.150 Small parcel requirement no. 1 – Construction access route.

Construction vehicle access shall be, whenever possible, limited to one route. Access points shall be stabilized with quarry spall or crushed rock to minimize the tracking of sediment onto public roads. (Ord. 312 § 7.1.1, 1995).

13.20.160 Small parcel requirement no. 2 – Stabilization of denuded areas.

All exposed soils shall be stabilized by suitable application of BMPs, including but not limited to sod or other vegetation, plastic covering, mulching, or application of ground base on areas to be paved. All BMPs shall be selected, designed and maintained in accordance with an approved manual. From October 1st through April 30th, no soils shall remain exposed for more than two days. From May 1st through September 30th, no soils shall remain exposed for more than seven days. (Ord. 312 § 7.1.2, 1995).

13.20.170 Small parcel requirement no. 3 – Protection of adjacent properties.

Adjacent properties shall be protected from sediment deposition by appropriate use of vegetative buffer strips, sediment barriers or filters, dikes or mulching, or by a combination of these measures and other appropriate BMPs. (Ord. 312 § 7.1.3, 1995).

13.20.180 Small parcel requirement no. 4 – Maintenance.

All erosion and sediment control BMPs shall be regularly inspected and maintained to ensure continues performance on their intended function. (Ord. 312 § 7.1.4, 1995).

13.20.190 Small parcel requirement no. 5 – Other BMPs.

As required by the town of Index, other appropriate BMPs to mitigate the effects of increased runoff shall be applied. (Ord. 312 § 7.1.5, 1995).

13.20.200 Large development minimum requirements – New development.

(A) All new development that includes the creation or addition of 5,000 square feet, or greater, of new impervious surface area and/or land disturbing activity of one acre or greater shall comply with minimum requirements no. 1 through no. 11 in Sections 13.20.220 through 13.20.320.

Compliance shall be demonstrated through the implementation of an approved storm water site plan consisting of a large parcel ESC plan and a PSQC plan, as appropriate.

(B) All new development that includes the creation or addition of 5,000 square feet, or greater, of new impervious surface area and land disturbing activity of less than one acre shall comply with minimum requirements no. 2 through no. 11 in Sections 13.20.230 through 13.20.320 and the small parcel erosion and sediment control plan and a PSQC plan.

Compliance shall be demonstrated through the implementation of an approved storm water site plan that includes a small parcel erosion and sediment control plan and a PSQC plan.

This section does not apply to the construction of individual, detached, single-family residences and duplexes. Those types of new development are included in the small parcel minimum requirements. (Ord. 312 § 7.2.1, 1995).

13.20.210 Large development minimum requirements – Redevelopment.

(A) Where redevelopment of greater than or equal to 5,000 square feet occurs: New development minimum requirements no. 1 through no. 11 in Sections 13.20.220 through 13.20.320 shall apply to that portion of the site that is being redeveloped, and source control BMPs shall be applied to the entire site, including adjoining parcels if they are part of the project.

(B) In addition to the above requirements, where one or more of the following conditions apply, a storm water management plan shall be prepared that includes a schedule for implementing the minimum requirements to the maximum extent practicable, for the entire site, including adjoining parcels if they are part of the project.

(1) Existing sites greater than one acre in size with 50 percent or more impervious surface.

(2) Sites that discharge to a receiving water that has a documented water quality problem. Subject to local priorities, a documented water quality problem includes, but is not limited to, water bodies:

(a) Listed in reports required under Section 305(b) of the Clean Water Act, and designated as not supporting beneficial uses;

(b) Listed under Section 304(i)(1) (A)(ii), or 304(i)(1)(B) of the Clean Water Act as not expected to meet water quality standards or water quality goals.

(3) Sites where the need for additional storm water control measures have been identified through a basin plan, the watershed ranking process under Chapter 400-12 WAC, or through Growth Management Act planning. (Ord. 312 § 7.2.2, 1995).

13.20.220 Minimum requirement no. 1 – Erosion and sediment control.

(A) All new development and redevelopment that includes land distributing activities greater than or equal to one acre shall comply with erosion and sediment control requirements in subsection D of this section. Compliance with the erosion and sediment control requirements shall be demonstrated through implementation of an approved large parcel erosion and sediment control plan.

(B) All new development and redevelopment that includes land disturbing activities of greater than one acre shall comply with the small parcel minimum requirements found in Section 13.20.140.

(C) Compliance with the small parcel requirements shall be demonstrated through implementation of a small parcel erosion and sediment control plan.

(D) The following erosion and sediment control requirements shall be met:

(1) Erosion and Sediment Control Requirement No. 1 – Stabilization and Sediment Trapping. All exposed and unworked soils shall be stabilized by suitable application of BMPs. From October 1st to April 30th, no soils shall remain unstabilized for more than two days. From May 1st to September 30th, no soils shall remain unstabilized for more than seven days. Prior to leaving the site, storm water runoff shall pass through a sediment pond or sediment trap, or other appropriate BMPs.

(2) Erosion and Sediment Control Requirement No. 2 – Delineate Clearing and Easement Limits. In the field, mark clearing limits and/or any easements, setbacks, sensitive/critical areas and their buffers, trees and drainage courses.

(3) Erosion and Sediment Control Requirement No. 3 – Protection of Adjacent Properties. Properties adjacent to the project site shall be protected from sediment deposition.

(4) Erosion and Sediment Control Requirement No. 4 – Timing and Stabilization of Sediment Trapping Measures. Sediment ponds and traps, perimeter dikes, sediment barriers, and other BMPs intended to trap sediment on-site shall be constructed as a first step in grading. These BMPs shall be functional before land disturbing activities take place. Earthen structures such as dams, dikes, and diversions shall be seeded and mulched according to the timing indicated in erosion and sediment control requirement no. 1.

(5) Erosion and Sediment Control Requirement No. 5 – Cut and Fill Slopes. Cut and fill slopes shall be designed and constructed in a manner that will minimize erosion. In addition, slopes shall be stabilized in accordance with erosion and sediment control requirement no. 1.

(6) Erosion and Sediment Control Requirement No. 6 – Controlling Off-Site Erosion. Properties and waterways downstream from development sites shall be protected from erosion due to increases in the volume, velocity, and peak flow rate of storm water runoff from the project site.

(7) Erosion and Sediment Control Requirement No. 7 – Stabilization of Temporary Conveyance Channels and Outlets. All temporary on-site conveyance channels shall be designed, constructed and stabilized to prevent erosion from the expected velocity of flow from a two-year, 24-hour frequency storm for the developed condition. Stabilization adequate to prevent erosion of outlets, adjacent streambanks, slopes and downstream reaches shall be provided at the outlet of all conveyance systems.

(8) Erosion and Sediment Control Requirement No. 8 – Storm Drain Inlet Protection. All storm drain inlets made operable during construction shall be protected so that storm water runoff shall not enter the conveyance system without first being filtered or otherwise treated to remove sediment.

(9) Erosion and Sediment Control Requirement No. 9 – Underground Utility Construction. The construction of underground utility lines shall be subject to the following criteria:

(a) Where feasible, no more than 500 feet of trench shall be opened at one time.

(b) Where consistent with safety and space considerations, excavated material shall be placed on the uphill side of the trench.

(10) Erosion and Sediment Control Requirement No. 10 – Construction Access Routes. Wherever construction vehicle access routes intersect paved roads, provisions must be made to minimize the transport of sediment (mud) onto the paved road. If sediment is transported onto a road surface, the road shall be cleaned thoroughly at the end of each day. Sediment shall be removed from roads by shoveling or sweeping and be transported to a controlled sediment disposal area. Street washing shall be allowed only after sediment is removed in this manner.

(11) Erosion and Sediment Control Requirement No. 11 – Removal of Temporary BMPs. All temporary erosion and sediment control BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no linger needed. Trapped sediment shall be removed or stabilized on-site. Disturbed soil areas resulting from removal shall be permanently stabilized.

(12) Erosion and Sediment Control Requirement No. 12 – Dewatering Construction Sites. Dewatering devices shall discharge into a sediment trap or sediment pond.

(13) Erosion and Sediment Control Requirement No. 13 – Control of Pollutants Other Than Sediment on Construction Sites. All pollutants other than sediment that occur on-site during construction shall be handled and disposed of in a manner that does not cause contamination of storm water.

(14) Erosion and Sediment Control Requirement No. 14 – Maintenance. All temporary and permanent erosion and sediment control BMPs shall be maintained and repaired as needed to assure continued performance of their intended function. All maintenance and repair shall be constructed in accordance with an approved manual.

(15) Erosion and Sediment Control Requirement No. 15 – Financial Liability. Performance bonding, or other appropriate financial instruments, shall be required for all projects to ensure compliance with the approved erosion and sediment control plan. (Ord. 312 § 7.2.3, 1995).

13.20.230 Minimum requirement no. 2 – Preservation of natural drainage systems.

Natural drainage patterns shall be maintained and discharges from the site shall occur at the natural location, to the maximum extent practicable. (Ord. 312 § 7.2.4, 1995).

13.20.240 Minimum requirement no. 3 – Source control of pollution.

(A) Source control BMPs shall be applied to all projects to the maximum extent practicable. Source control BMPs shall be selected, designed, and maintained according to an approved manual.

(B) An adopted and implemented basin plan (minimum requirement no. 9) may be used to develop source control requirements that are tailored to a specific basin, however, in all circumstances, source control BMPs shall be required for all sites. (Ord. 312 § 7.2.5, 1995).

13.20.250 Minimum requirement no. 4 – Runoff treatment BMPs.

(A) All projects shall provide treatment of storm water. Treatment BMPs shall be sized to capture and treat the water quality design storm, defined as the six-month, 24-hour return period storm. The first priority for treatment shall be to infiltrate as much as possible of the water quality design storm, only if site conditions are appropriate and ground water quality will not be impaired. Direct discharge of untreated storm water to ground water is prohibited. All treatment BMPs shall be selected, designed, and maintained according to an approved manual.

(B) Storm water treatment BMPs shall not be built within a natural vegetated buffer, except for necessary conveyance systems as approved by the town of Index.

(C) An adopted and implemented basin plan (minimum requirement no. 9) may be used to develop runoff treatment requirements that are tailored to a specific basin. (Ord. 312 § 7.2.6, 1995).

13.20.260 Minimum requirement no. 5 – Streambank erosion control.

The requirement below applies only to situations where storm water runoff is discharged directly or indirectly to a stream and must be met in addition to meeting the requirements in minimum requirement no. 4, runoff treatment BMPs:

(A) Storm water discharges to streams shall control streambank erosion by limiting the peak rate of runoff from individual development sites to 50 percent of the existing condition two-year, 24-hour and 100-year, 24-hour design storms. As the first priority, streambank erosion control BMPs shall utilize infiltration to the fullest extent practicable, only if site conditions are appropriate and ground water quality is protected. Streambank erosion control BMPs shall be selected, designed, and maintained according to an approved manual.

(B) Storm water treatment BMPs shall not be built within a natural vegetated buffer, except for necessary conveyance systems as approved by the town of Index.

(C) An adopted and implemented basin plan (minimum requirement no. 9) may be used to develop streambank erosion control requirements that are tailored to a specific basin. (Ord. 312 § 7.2.7, 1995).

13.20.270 Minimum requirement no. 6 – Wetlands.

(A) The requirements below apply only to situations where storm water discharges directly or indirectly through a conveyance system into a wetland and must be met in addition to meeting the requirements in minimum standard no. 4, runoff treatment BMPs.

(1) Storm water discharges to wetlands must be controlled and treated to the extent necessary to meet the State Water Quality Standards, Chapter 173-201 WAC, or Ground Water Quality Standards, Chapter 173-200 WAC, as appropriate.

(2) Discharges to wetlands shall maintain the hydroperiod and flows of existing site conditions to the extent necessary to protect the characteristic uses of the wetland.

Prior to discharging to a wetland, alternative discharge locations shall be evaluated and natural water storage and infiltration opportunities outside the wetland shall be maximized.

(3) Created wetlands that are intended to mitigate for loss of wetland acreage, function and value shall not be designed to also meet storm water.

(4) In order for constructed wetlands to be considered treatment systems, they must be constructed on sites that are not wetlands and they must be managed for storm water treatment. If these systems are not managed and maintained in accordance with an approved manual for a period exceeding three years these systems may no longer be considered constructed wetlands. Discharged from constructed wetlands to waters of the state (including discharges to natural wetlands) are required under Chapter 90.48 RCW, Chapter 173-201 WAC, and Chapter 173-200 WAC.

(5) Storm water treatment BMPs shall not be built within a natural vegetated buffer, except for necessary conveyance systems as approved by the local government.

(B) An adopted and implemented basin plan (minimum requirement no. 9) may be used to develop requirements for wetlands that are tailored to a specific basin. (Ord. 312 § 7.2.8, 1995).

13.20.280 Minimum requirement no. 7 – Water quality sensitive areas.

(A) Where the town of Index determines that the minimum requirements do not provide adequate protection of water quality sensitive areas, either on-site or within the basin, more stringent controls shall be required to protect water quality.

(B) Storm water treatment BMPs shall not be built within the natural vegetative buffer, except for necessary conveyance systems as approved by the local government.

(C) An adopted and implemented basin plan may be used to develop requirements for water quality sensitive areas that are tailored to a specific basin. (Ord. 312 § 7.2.9, 1995).

13.20.290 Minimum requirement no. 8 – Off-site analysis and mitigation.

All development projects shall conduct an analysis of off-site water quality impacts resulting from the project and shall mitigate these impacts. The analysis should extend a minimum of one-fourth of a mile downstream from the project. The existing or potential impacts to be evaluated and mitigated shall include, at a minimum, but not be limited to:

(1) Excessive sedimentation;

(2) Streambank erosion;

(3) Discharges to ground water contributing or recharge zones;

(4) Violations of water quality standards;

(5) Spills and discharges of priority pollutants. (Ord. 312 § 7.2.10, 1995).

13.20.300 Minimum requirement no. 9 – Basin planning.

Adopted and implemented watershed-based plans may be used to modify any or all of the minimum requirements; provided, that the level of protection for surface or ground water achieved by the basin plan will equal or exceed that which would be achieved by the minimum requirements in the absence of a basin plan. Basin plans shall evaluate and include, as necessary, retrofitting of BMPs for existing development and/or redevelopment in order to achieve watershed-wide pollutant reduction goals. Standards developed from basin plans shall not modify any of the above requirements until the basin plan is formally adopted and fully implemented by the town of Index. Basin plans shall be developed according to an approved manual. (Ord. 312 § 7.2.11, 1995).

13.20.310 Minimum requirement no. 10 – Operation and maintenance.

An operation and maintenance schedule shall provide for all proposed storm water facilities and BMPs and the party (or parties) responsible for maintenance and operation shall be identified. (Ord. 312 § 7.2.12, 1995).

13.20.320 Minimum requirement no. 11 – Financial liability.

Performance bonding or other appropriate financial instruments shall be required for all projects to ensure compliance with these standards. (Ord. 312 § 7.2.13, 1995).

13.20.330 Minimum requirements – Exceptions.

Exceptions to minimum requirements no. 1 through no. 11 may be granted prior to permit approval and construction. An exception may be granted following a public hearing; provided, that a written finding of fact is prepared that addresses the following:

(A) The exception provides equivalent environmental protection and is in the overriding public interest; and that the objectives of safety, function, environmental protection and facility maintenance, based upon sound engineering, are fully met;

(B) That there are special physical circumstances or conditions affecting the property such that the strict application of these provisions would deprive the applicant of all reasonable use of the parcel of land in question, and every effort to find creative ways to meet the intent of the minimum standards has been made;

(C) That the granting of the exception will not be detrimental to the public health and welfare nor injurious to other properties in the vicinity and/or downstream and to the quality of the waters of the state; and

(D) The exception is the least possible exception that could be granted to comply with the intent of the minimum requirements. (Ord. 312 § 7.2.14, 1995).

13.20.340 Director.

The town of Index mayor or designee shall administer this chapter and shall be referred to as the director. The director shall have the authority to develop and implement administrative procedures to administer and enforce this chapter. (Ord. 312 § 8.1, 1995).

13.20.350 Applications – Review and approval.

The director may approve, conditionally approve or deny any application for activities regulated by this chapter. (Ord. 312 § 8.2, 1995).

13.20.360 Enforcement authority.

The director shall enforce this chapter. (Ord. 312 § 8.3, 1995).

13.20.370 Inspections.

All activities regulated by this chapter, except those exempt in Section 13.20.100, shall be inspected by the director. The director shall inspect projects at various stages of the work requiring approval to determine that adequate control is being exercised. Stages of work requiring inspection include, but are not limited to, preconstruction; installation of BMPs; land disturbing activities; installation of utilities, landscaping, retaining walls and completion of project. When required by the director, a special inspection and/or testing shall be performed. (Ord. 312 § 8.4, 1995).

13.20.380 Enforcement.

Enforcement action shall be in accordance with this chapter whenever a person has violated any provision of this chapter. The choice of enforcement action and the severity of any penalty shall be based on the nature of the violation, the damage or risk to the public or to public resources and/or the degree of bad faith of the person subject to the enforcement action. (Ord. 312 § 9.1, 1995).

13.20.390 Stop work order.

The director shall have the authority to serve a person with a stop work order if an action is being undertaken in violation of this chapter.

(A) Content of Order. The order shall contain:

(1) A description of the specific nature, extent, and time of violation and the damage or potential damage; and

(2) A notice that the violation or the potential violation cease and desist and, in appropriate cases, the specific corrective action to be taken within a given time. A civil penalty under Section 13.20.400 may be issued with the order.

(B) Notice. A stop work order shall be imposed by a notice in writing, either by certified mail with return receipt requested or by personal service, to the person incurring the same.

(C) Effective Date. The stop work order issued under this section shall become effective immediately upon receipt by the person to whom the order is directed.

(D) Compliance. Failure to comply with the terms of a stop work order shall result in enforcement actions including, but not limited to, the issuance of a civil penalty. (Ord. 312 § 9.2, 1995).

13.20.400 Civil penalty.

A person who fails to comply with the requirements of this chapter, who fails to conform to the terms of an approval or order issued, who undertakes new development without first obtaining town of Index approval, or who fails to comply with a stop work order issued under these regulations shall be subject to a civil penalty.

(A) Amount of Penalty. The penalty shall not be less than $100.00 or exceed $500.00 for each violation. Each day of continued violation or repeated violation shall constitute a separate violation.

(B) Aiding or Abetting. Any person who, through an act of commission or omission, aids or abets in the violation shall be considered to have committed a violation for the purpose of the civil penalty.

(C) Notice of Penalty. A civil penalty shall be imposed by a notice in writing, either by certified mail with return receipt requested or by personal service, to the person incurring the same from the town of Index. The notice shall describe the violation, approximate the date(s) of violation, and shall order the acts constituting the violation to cease and desist, and, in appropriate cases, require necessary corrective action within a specific time.

(D) Application for Remission or Mitigation. Any person incurring a penalty may apply in writing within 15 days of the receipt of the penalty to the town of Index for remission or mitigation of such penalty. Upon receipt of the application, the town of Index may remit or mitigate the penalty only upon a demonstration of extraordinary circumstances, such as the presence of information or factors not considered in setting the original penalty. The decision may be appealed to the town of Index within 15 days of the decision. (Ord. 312 § 9.3, 1995).

13.20.410 Penalties due when.

Penalties imposed under Section 13.20.400 shall become due and payable 15 days after receiving it unless application for remission or mitigation is made or an appeal is filed. Whenever an application for remission or mitigation is made, penalties shall become due and payable 30 days after receipt of the decision regarding the remission or mitigation. Whenever an appeal of penalty is filed, the penalty shall become due and payable after all review proceedings and a final decision has been issued confirming all or part of the penalty. If the amount of a penalty owed the town of Index is not paid within the time specified, the town of Index may take actions necessary to recover such penalty. (Ord. 312 § 9.3.1, 1995).

13.20.420 Exception – Board of appeals.

After a public hearing, the town of Index may grant an exception from the requirements of this chapter. In granting any exception, the town of Index may prescribe conditions that are deemed necessary or desirable for the public interest. (Ord. 312 § 10.1, 1995).

13.20.430 Exception – Finding of fact required.

Exceptions to minimum requirements no. 1 thorough no. 11 may be granted prior to permit approval and construction. An exception may be granted following a public hearing; provided, that a written finding of fact is prepared that addresses the following:

(B) That there are special physical circumstances or conditions affecting the property such that the strict application of these provisions would deprive the applicant all reasonable use of the parcel of land in question, and every effort to find creative ways to meet the intent of the minimum standards has been made;

(C) That the granting of the exception will not be detrimental to the public health and welfare, nor injurious to other properties in the vicinity and/or downstream and to the quality of waters of the state; and

(D) The exception is the least possible exception that could be granted to comply with the intent of the minimum requirements. (Ord. 312 § 10.2, 1995).

13.20.440 Exception – Prior approval.

Any exception shall be approved prior to permit approval and construction. (Ord. 312 § 10.3, 1995).

13.20.450 Exception – Duration.

Exceptions granted shall be valid for two years, unless granted for a shorter period. (Ord. 312 § 10.4, 1995).

13.20.460 Right of appeal.

All actions of the town of Index shall be final and conclusive, unless within 15 days of the date of the town of Index’s action the original applicant or an adverse party gives written notice to appeal to the town of Index for review of the action. (Ord. 312 § 10.5, 1995).

13.20.470 Maintenance – Minimum standards.

The following are the minimum standards for the maintenance of storm water facilities:

(A) Facilities shall be inspected annually and cleaned of debris, sediment and vegetation when they affect the functioning and/or design capacity of the facility.

(B) Grassy swales and other biofilters shall be inspected monthly and mowed or replanted as necessary. Clippings are to be removed and properly disposed of.

(C) Where lack of maintenance is causing or contributing to a water quality problem, immediate action shall be taken to correct the problem. Within one month, the director shall revisit the facility to assure that it is being maintained. (Ord. 312 § 12, 1995).