Chapter 17.95
STANDARD URBAN STORMWATER MITIGATION PLAN IMPLEMENTATION
Sections:
17.95.020 Scope and Applicability.
17.95.060 Best Management Practices (BMPs).
17.95.070 Control of Erosion of Slopes and Channels.
17.95.080 Signage of Storm Drains.
17.95.090 Outdoor Storage of Materials.
17.95.100 Outdoor Trash Storage Areas.
17.95.110 Maintenance of Best Management Practices.
17.95.120 Design Standards for Stormwater Pollution Control Requirements.
17.95.220 Alternative Compliance—Technical Infeasibility.
17.95.010 Purpose of Chapter.
The provisions of this chapter contain requirements for post-construction stormwater activities and facility operations of development and redevelopment projects to comply with the current “Waste Discharge Requirements for Municipal Separate Storm Sewer System (MS4)” issued by the California Regional Water Quality Control Board—Los Angeles Region (Order No. R4-2012-0175), which also serves as a National Pollutant Discharge Elimination System (NPDES) permit under the Federal Clean Water Act (NPDES No. CAS004001), and waste discharge requirements under California law (the “Municipal NPDES permit”), lessen the water quality impacts of development by using smart growth practices, and integrate low-impact development (LID) design principles to mimic predevelopment hydrology through infiltration, evapotranspiration and rainfall harvest, and use. LID shall be inclusive of previously adopted Standard Urban Stormwater Mitigation Plan (SUSMP) requirements.
Nothing in this chapter shall be interpreted to:
A. Infringe any right or power guaranteed by the California Constitution, including any vested property right; or
B. Require any action inconsistent with any applicable and lawfully adopted general plan, specific plan, plan amendment, or building code that conforms to the laws of California and the requirements of this chapter; or
C. Restrict otherwise lawful land use except as authorized by the laws of California, subject to the limitations of this chapter. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.020 Scope and Applicability.
A. Scope. This section contains requirements for stormwater pollution control measures in development and redevelopment planning priority projects and authorizes the City of Santa Clarita (City) to further define and adopt stormwater pollution control measures, to develop LID principles and requirements, including but not limited to the objectives and specifications for integration of LID strategies, and to grant alternate compliance as allowed by the municipal NPDES permit and collect fees from projects granted exceptions. Except as otherwise provided herein, the City shall administer, implement, and enforce the provisions of this section. Guidance documents supporting implementation of requirements in this chapter are hereby incorporated by reference, including SUSMP and the Los Angeles County Low Impact Development Standards Manual, and all future amendments.
B. Applicability.
1. All development projects equal to one (1) acre or greater of disturbed area that adds more than ten thousand (10,000) square feet of impervious surface area.
2. Single-family hillside homes.
3. Industrial parks with ten thousand (10,000) square feet or more of surface area.
4. Commercial malls with ten thousand (10,000) square feet or more of surface area.
5. Automotive service facilities (Standard Industrial Classification (SIC) of 5013, 5014, 5511, 5541, 7532-7534 and 7536-7539) with five thousand (5,000) square feet or more of surface area.
6. Retail gasoline outlets with five thousand (5,000) square feet or more of surface area.
7. Restaurants (Standard Industrial Classification (SIC) of 5812) with five thousand (5,000) square feet or more of surface area.
8. Parking lots with five thousand (5,000) square feet or more of impervious surface area or with twenty-five (25) or more parking spaces.
9. Street and road construction of ten thousand (10,000) square feet or more of impervious surface area.
10. Projects located in or directly adjacent to, or discharging directly to a significant ecological area (SEA), where the development will:
a. Discharge stormwater runoff that is likely to impact a sensitive biological species or habitat; and
b. Create two thousand five hundred (2,500) square feet or more of impervious surface area.
11. Redevelopment Projects.
a. Land disturbing activity that results in the creation, addition, or replacement of five thousand (5,000) square feet or more of impervious surface area on an already developed site on planning priority project categories.
b. Where redevelopment results in an alteration to more than fifty percent (50%) of impervious surfaces of a previously existing development, and the existing development was not subject to post-construction stormwater quality control requirements, the entire project must be mitigated.
c. Where redevelopment results in an alteration of less than fifty percent (50%) of impervious surfaces of a previously existing development, and the existing development was not subject to post-construction stormwater quality control requirements, only the alteration must be mitigated, and not the entire development.
d. Redevelopment does not include routine maintenance activities that are conducted to maintain original line and grade, hydraulic capacity, original purpose of facility or emergency redevelopment activity required to protect public health and safety. Impervious surface replacement, such as the reconstruction of parking lots and roadways which does not disturb additional area and maintains the original grade and alignment, is considered a routine maintenance activity. Redevelopment does not include the repaving of existing roads to maintain original line and grade.
e. Existing single-family dwelling and accessory structures are exempt from the redevelopment requirements unless such projects create, add, or replace ten thousand (10,000) square feet of impervious surface area.
C. Effective Date. This chapter shall take effect on January 1, 2016, and shall apply only to approval of discretionary (within the meaning of the California Environmental Quality Act, Public Resources Code Section 21000 et seq.) new development or redevelopment planning priority projects (as those terms are defined in this chapter). (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.030 Definitions.
For the purposes of this chapter, the following words and phrases shall have the meanings respectively ascribed to them by this chapter, unless clearly inapplicable. Words and phrases not ascribed a meaning by this chapter shall have the meanings ascribed by the “Waste Discharge Requirements for Municipal Separate Storm Sewer System (MS4) Discharges within the Coastal Watersheds of Los Angeles County, Except those Discharges Originating from the City of Long Beach MS4,” issued by the California Regional Water Quality Control Board—Los Angeles Region (Order No. R4-2012-0175), or as modified by the State Water Resources Control Board, if defined therein, and if not, by the regulations implementing Clean Water Act Section 402, and Division 7 of the California Water Code, as they may be amended from time to time, if defined therein, and if not, to the definitions in an applicable permit issued by the California Regional Water Quality Control Board—Los Angeles (Regional Board), as such permits may be amended from time to time.
“Automotive service facility” means a facility that is categorized in any one (1) of the following Standard Industrial Classification (SIC) and North American Industry Classification System (NAICS) codes. For inspection purposes, permittees need not inspect facilities with SIC codes 5013, 5014, 5541, and 5511, provided these facilities have no outside activities or materials that may be exposed to stormwater. (Source: Order No. R4-2012-0175.)
“Basin plan” means the Water Quality Control Plan, Los Angeles Region, Basin Plan for the Coastal Watersheds of Los Angeles and Ventura Counties, adopted by the Regional Water Board on June 13, 1994, and subsequent amendments. (Source: Order No. R4-2012-0175.)
“Best management practice (BMP)” means any practices or physical devices or systems designed to prevent or reduce pollutant loading from stormwater or nonstormwater discharges to receiving waters, or designed to reduce the volume of stormwater or nonstormwater discharged to the receiving water. (Source: Order No. R4-2012-0175.)
“Biofiltration” means a LID BMP that reduces stormwater pollutant discharges by intercepting rainfall on vegetative canopy, and through incidental infiltration and/or evapotranspiration, and filtration. Incidental infiltration is an important factor in achieving the required pollutant load reduction. Therefore, the term “biofiltration,” as used in this chapter, is defined to include only systems designed to facilitate incidental infiltration or achieve the equivalent pollutant reduction as biofiltration BMPs with an underdrain (subject to approval by the Regional Board’s Executive Officer). Biofiltration BMPs include bioretention systems with an underdrain and bioswales. (Modified from: Order No. R4-2012-0175.)
“Bioretention” means a LID BMP that reduces stormwater runoff by intercepting rainfall on vegetative canopy, and through evapotranspiration and infiltration. The bioretention system typically includes a minimum two (2) foot top layer of a specified soil and compost mixture underlain by a gravel-filled temporary storage pit dug into the in-situ soil. As defined in the municipal NPDES permit, a bioretention BMP may be designed with an overflow drain, but may not include an underdrain. When a bioretention BMP is designed or constructed with an underdrain it is regulated by the municipal NPDES permit as biofiltration. (Modified from: Order No. R4-2012-0175.)
“Bioswale” means a LID BMP consisting of a shallow channel lined with grass or other dense, low-growing vegetation. Bioswales are designed to collect stormwater runoff and to achieve a uniform sheet flow through the dense vegetation for a period of several minutes. (Source: Order No. R4-2012-0175.)
“Clean Water Act (CWA)” means the Federal Water Pollution Control Act enacted in 1972, by Public Law 92-500, and amended by the Water Quality Act of 1987. The Clean Water Act prohibits the discharge of pollutants to waters of the United States unless the discharge is in accordance with an NPDES permit.
“Commercial malls” means any development comprised of one (1) or more buildings forming a complex of stores, which sells various merchandise, with interconnecting walkways enabling visitors to easily walk from store to store, along with parking area(s). A commercial mall includes, but is not limited to: mini-malls, strip malls, other retail complexes, and enclosed shopping malls or shopping centers. (Source: Order No. R4-2012-0175.)
“Construction activity” means any construction or demolition activity, clearing, grading, grubbing, or excavation or any other activity that results in land disturbance. Construction does not include emergency construction activities required to immediately protect public health and safety or routine maintenance activities required to maintain the integrity of structures by performing minor repair and restoration work, maintain the original line and grade, hydraulic capacity, or original purposes of the facility. See “routine maintenance” definition for further explanation. Where clearing, grading, or excavating of underlying soil takes place during a repaving operation, State general construction permit coverage by the State of California general permit for stormwater discharges associated with industrial activities or for stormwater discharges associated with construction activities is required if more than one (1) acre is disturbed or the activities are part of a larger plan. (Source: Order No. R4-2012-0175.)
“Control” means to minimize, reduce, or eliminate by technological, legal, contractual, or other means, the discharge of pollutants from an activity or activities. (Source: Order No. R4-2012-0175.)
“Development” means construction, rehabilitation, redevelopment, or reconstruction of any public or private residential project (whether single-family, multi-unit, or planned unit development); industrial, commercial, retail, and other nonresidential projects, including public agency projects or mass grading for future construction. It does not include routine maintenance to maintain original line and grade, hydraulic capacity, or original purpose of facility, nor does it include emergency construction activities required to immediately protect public health and safety. (Source: Order No. R4-2012-0175.)
“Directly adjacent” means situated within two hundred (200) feet of the contiguous zone required for the continued maintenance, function, and structural stability of the environmentally sensitive area. (Source: Order No. R4-2012-0175.)
“Discharge” means any release, spill, leak, pump, flow, escape, dumping, or disposal of any liquid, semi-solid, or solid substance.
“Disturbed area” means an area that is altered as a result of clearing, grading, and/or excavation. (Source: Order No. R4-2012-0175.)
“Flow-through BMPs” means modular, vault type “high flow biotreatment” devices contained within an impervious vault with an underdrain or designed with an impervious liner and an underdrain. (Modified from: Order No. R4-2012-0175.)
“General construction activities stormwater permit (GCASP)” means the general NPDES permit adopted by the State Board, which authorizes the discharge of stormwater from construction activities under certain conditions.
“General industrial activities stormwater permit (GIASP)” means the general NPDES permit adopted by the State Board, which authorizes the discharge of stormwater from certain industrial activities under certain conditions.
“Green roof” means a LID BMP using planter boxes and vegetation to intercept rainfall on the roof surface. Rainfall is intercepted by vegetation leaves and through evapotranspiration. Green roofs may be designed as either a bioretention BMP or as a biofiltration BMP. To receive credit as a bioretention BMP, the green roof system planting medium shall be of sufficient depth to provide capacity within the pore space volume to contain the design storm depth and may not be designed or constructed with an underdrain. (Source: Order No. R4-2012-0175.)
“Hazardous material(s)” means any material(s) defined as hazardous by Division 20, Chapter 6.95 of the California Health and Safety Code.
“Hillside” means a property located in an area with known erosive soil conditions, where the development contemplates grading on any natural slope that is twenty-five percent (25%) or greater and where grading contemplates cut or fill slopes. (Source: Order No. R4-2012-0175.)
“Hydromodification” means the alteration of the hydrologic characteristics of coastal and noncoastal waters, which in turn could cause degradation of water resources. Hydromodification can cause excessive erosion and/or sedimentation rates, causing excessive turbidity, channel aggradation, and/or degradation. (Source: general construction activities stormwater permit.)
“Impervious surface” means any manmade or modified surface that prevents or significantly reduces the entry of water into the underlying soil, resulting in runoff from the surface in greater quantities and/or at an increased rate, when compared to natural conditions prior to development. Examples of places that commonly exhibit impervious surfaces include parking lots, driveways, roadways, storage areas, and rooftops. The imperviousness of these areas commonly results from paving, compacted gravel, compacted earth, and oiled earth.
“Industrial park” means land development that is set aside for industrial development. Industrial parks are usually located close to transport facilities, especially where more than one (1) transport modalities coincide: highways, railroads, airports, and navigable rivers. It includes office parks, which have offices and light industry. (Source: Order No. R4-2012-0175.)
“Infiltration BMP” means a LID BMP that reduces stormwater runoff by capturing and infiltrating the runoff into in-situ soils or amended on-site soils. Examples of infiltration BMPs include infiltration basins, dry wells, and pervious pavement. (Source: Order No. R4-2012-0175.)
“Low impact development (LID)” means any building and landscape features designed to retain or filter stormwater runoff. (Source: Order No. R4-2012-0175.)
“MS4” means municipal separate storm sewer system (MS4). The MS4 is a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, manmade channels, or storm drains):
1. Owned or operated by a state, city, town, borough, county, parish, district, association, or other public body (created by or pursuant to State law) having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under State law such as a sewer district, flood control district or drainage district, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the CWA that discharges to waters of the United States;
2. Designed or used for collecting or conveying stormwater;
3. Which is not a combined sewer; and
4. Which is not part of a publicly owned treatment works, as defined in 40 C.F.R. Section 122.2.26(b)(8). (Source: Order No. R4-2012-0175.)
“National Pollutant Discharge Elimination System (NPDES)” means the national program for issuing, modifying, revoking and reissuing, terminating, monitoring and enforcing permits, and imposing and enforcing pretreatment requirements, under CWA Sections 307, 402, 318, and 405. The term includes an “approved program.” (Source: Order No. R4-2012-0175.)
“Natural drainage system” means a drainage system that has not been improved (e.g., channelized or armored). The clearing or dredging of a natural drainage system does not cause the system to be classified as an improved drainage system. (Source: Order No. R4-2012-0175.)
“New development” means land-disturbing activities; structural development, including construction or installation of a building or structure, creation of impervious surfaces; and land subdivision. (Source: Order No. R4-2012-0175.)
“Nonstormwater discharge” means any discharge to a municipal storm drain system not composed entirely of stormwater. (Source: Order No. R4-2012-0175.)
“Parking lot” means an area or facility for the temporary parking or storage of motor vehicles used for businesses or commerce, industry, or personal use, with a lot size of five thousand (5,000) square feet or more of surface area, or with twenty-five (25) or more parking spaces. (Source: Order No. R4-2012-0175.)
“Planning priority projects” means development projects subject to permittee conditioning and approval for the design and implementation of post-construction controls to mitigate stormwater pollution, prior to completion of the project(s). (Modified from: Order No. R4-2012-0175.)
“Pollutant” means any pollutant defined in Section 502(6) of the Federal Clean Water Act or incorporated into the California Water Code Section 13373. Pollutants may include, but are not limited to, the following:
1. Commercial and industrial wastes (such as fuels, solvents, detergents, plastic pellets, hazardous substances, fertilizers, pesticides, slag, ash, and sludge).
2. Metals (such as cadmium, lead, zinc, copper, silver, nickel, chromium, and nonmetals such as phosphorus and arsenic).
3. Petroleum hydrocarbons (such as fuels, lubricants, surfactants, waste oils, solvents, coolants, and grease).
4. Excessive eroded soil, sediment, and particulate materials in amounts that may adversely affect the beneficial use of the receiving waters, flora, or fauna of the State.
5. Animal wastes (such as discharge from confinement facilities, kennels, pens, recreational facilities, stables, and show facilities).
6. Substances having characteristics such as pH less than six or greater than nine, or unusual coloration or turbidity, or excessive levels of fecal coliform, or fecal streptococcus, or enterococcus.
“Project” means all development, redevelopment, and land-disturbing activities. The term is not limited to “project” as defined under CEQA (Public Resources Code Section 21065). (Source: Order No. R4-2012-0175.)
“Rainfall harvest and use” means a LID BMP system designed to capture runoff, typically from a roof, but can also include runoff capture from elsewhere within the site, and to provide for temporary storage until the harvested water can be used for irrigation or nonpotable uses. The harvested water may also be used for potable water uses if the system includes disinfection treatment and is approved for such use by the local building department. (Source: Order No. R4-2012-0175.)
“Receiving water” means water of the United States into which waste and/or pollutants are or may be discharged. (Source: Order No. R4-2012-0175.)
“Redevelopment” means land-disturbing activity that results in the creation, addition, or replacement of five thousand (5,000) square feet or more of impervious surface area on an already developed site. Redevelopment includes, but is not limited to: the expansion of a building footprint; addition or replacement of a structure; replacement of impervious surface area that is not part of routine maintenance activity; and land-disturbing activity related to structural or impervious surfaces. It does not include routine maintenance to maintain original line and grade, hydraulic capacity, or original purpose of facility, nor does it include emergency construction activities required to immediately protect public health and safety. (Source: Order No. R4-2012-0175.)
“Restaurant” means a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and refreshment stands selling prepared foods and drinks for immediate consumption (SIC Code 5812). (Source: Order No. R4-2012-0175.)
“Retail gasoline outlet” means any facility engaged in selling gasoline and lubricating oils. (Source: Order No. R4-2012-0175.)
“Routine maintenance” means, but is not limited to, projects conducted to:
1. Maintain the original line and grade, hydraulic capacity, or original purpose of the facility.
2. Perform as-needed restoration work to preserve the original design grade, integrity and hydraulic capacity of flood control facilities.
3. Includes road shoulder work, regrading dirt or gravel roadways and shoulders, and performing ditch clean-outs.
4. Replacing existing lines with new materials or pipes and updating facilities to comply with applicable codes, standards, and regulations regardless if such projects result in increased capacity.
5. Repair leaks.
Routine maintenance does not include construction of new lines (i.e., that are not associated with existing facilities and are not part of a project to update or replace existing lines) or facilities resulting from compliance with applicable codes, standards, and regulations. (Source: Order No. R4-2012-0175.)
“Significant ecological areas (SEAs)” means areas that are determined to possess an example of biotic resources that cumulatively represent biological diversity, for the purposes of protecting biotic diversity, as part of the City of Santa Clarita General Plan. Areas are designated as SEAs if they possess one (1) or more of the following criteria:
1. The habitat of rare, endangered, and threatened plant and animal species.
2. Biotic communities, vegetative associations, and habitat of plant and animal species that are either one of a kind or are restricted in distribution on a regional basis.
3. Biotic communities, vegetative associations, and habitat of plant and animal species that are either one of a kind or are restricted in distribution in Los Angeles County.
4. Habitat that, at some point in the life cycle of a species or group of species, serves as a concentrated breeding, feeding, resting, or migrating grounds and is limited in availability either regionally or within Los Angeles County.
5. Biotic resources that are of scientific interest because they are either an extreme in physical/geographical limitations, or represent an unusual variation in a population or community.
6. Areas important as game species habitat or as fisheries.
7. Areas that would provide for the preservation of relatively undisturbed examples of natural biotic communities in Los Angeles County.
8. Special areas. (Source: Order No. R4-2012-0175.)
“Site” means land or water area where any facility or activity is physically located or conducted, including adjacent land used in connection with the facility or activity. (Source: Order No. R4-2012-0175.)
“Storm drain system” means any facilities or any part of those facilities, including streets, gutters, conduits, natural or artificial drains, channels, and watercourses, that are used for the purpose of collecting, storing, transporting or disposing of stormwater.
“Storm water” or “stormwater” means water that originates from atmospheric moisture (rain or snow) and that falls onto land, water, or other surfaces. Without any change in its meaning, this term may be spelled or written as one (1) word or two (2) separate words.
“Stormwater runoff” means that part of precipitation (rainfall or snowmelt), which travels across a surface to the storm drain system or receiving waters.
“SUSMP” means the Los Angeles Countywide Standard Urban Stormwater Mitigation Plan. The SUSMP was required as part of the previous municipal NPDES permit (Order No. 01-182, NPDES No. CAS004001) and required plans that designate best management practices (BMPs) that must be used in specified categories of development projects.
“Urban runoff” means surface water flow produced by storm and nonstorm events that is shed from both pervious and nonpervious surfaces. Nonstorm events that produce urban runoff include flow from residential, commercial, or industrial activities involving the use of potable and nonpotable water. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.040 Rate of Discharge.
No new development shall increase the peak rate of discharge of stormwater from the developed site if this increase would make downstream erosion more probable. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.050 Subdivision Design.
Unless inconsistent with vested rights, the site design for all subdivisions subject to this chapter, to the maximum extent practicable, shall:
A. Concentrate or cluster new development on portions of the site while leaving the remaining land in a natural undisturbed condition;
B. Limit clearing and grading of native vegetation to the minimum extent practicable, consistent with the construction of lots, and to allow access and provide fire protection;
C. Preserve riparian areas and wetlands. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.060 Best Management Practices (BMPs).
A. On the date the ordinance codified in this chapter takes effect, those BMPs which are listed in the Los Angeles County Low Impact Development (LID) Standards Manual shall be deemed to be incorporated by reference and adopted by this City and shall remain in effect until the City Council shall adopt by resolution a guidebook prepared or recommended by the City Engineer, categorizing development and BMPs for each category.
B. The City Engineer may from time to time revise the guidebook, and the City Council may adopt these revisions by resolution.
C. No BMP other than a structural or treatment control BMP shall be used in any development regulated under this chapter, unless the guidebook recommends that practice.
D. No structural or treatment control BMP may be used in any development regulated under this chapter unless the guidebook recommends that practice. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.070 Control of Erosion of Slopes and Channels.
BMPs used on slopes or channels in new development or redevelopment subject to this chapter shall:
A. Convey runoff from tops of slopes;
B. Eliminate or reduce flow to natural drainage systems, and for flows which cannot be eliminated, utilize natural drainage systems, rather than artificial drainage systems, to the maximum extent practicable;
C. Stabilize soil at permanent channel crossings;
D. Vegetate slopes with native or drought-tolerant species known to control erosion; and
E. Dissipate concentrated flows before they enter unlined channels. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.080 Signage of Storm Drains.
In the project area of new development or redevelopment subject to this chapter, a notice that dumping in storm drains and catch basins is illegal shall be:
A. Stenciled in paint or other permanent means at all storm drain inlets and catch basins within the project area;
B. Posted at all known public accesses to natural or artificial drainage channels within the project area; and
C. Maintained to preserve the sign. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.090 Outdoor Storage of Materials.
A. All materials stored outdoors in new development or redevelopment subject to this chapter which, if exposed to stormwater, may reasonably be expected to add pollutants to it, shall be thoroughly isolated from contact:
1. With stormwater, by enclosure in a structure; or
2. With stormwater, by a surrounding curb or other containment structure.
B. The storage area must be completely covered:
1. By impermeable paving; and
2. Any structure by an overhead covering that adequately diverts precipitation away from the ground between the material and the surrounding containment structure. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.100 Outdoor Trash Storage Areas.
Except where they serve only single-family residences, solid waste containers in new development or redevelopment subject to this chapter shall be stored in areas that:
A. Are isolated from contact with stormwater originating outside the storage area; and
B. Are surrounded with a barrier sufficient to prevent all trash and debris from being transported out of the storage area, except during collection. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.110 Maintenance of Best Management Practices.
A. Every person applying to the City for discretionary approval of any new development or redevelopment subject to this chapter, as part of that application, in a signed writing, shall agree to maintain any structural or treatment control BMP to be implemented in that development through means such as a covenant running with the land (such as covenants, conditions and restrictions, commonly known as CC&Rs), CEQA mitigation measures, conditional use permit or other legal agreement (collectively “agreement”).
B. The agreement described in subsection (A) of this section shall remain in force until ownership of the developed property has been entirely transferred, and upon transfer, shall be binding on the new owner(s). (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.120 Design Standards for Stormwater Pollution Control Requirements.
The site for every planning priority project shall be designed to control pollutants, pollutant loads, and runoff volume to the maximum extent feasible by minimizing impervious surface area and controlling runoff from impervious surfaces through infiltration, evapotranspiration, bioretention and/or rainfall harvest, and use.
A. A new single-family hillside home development shall include mitigation measures to:
1. Conserve natural areas;
2. Protect slopes and channels;
3. Provide storm drain system stenciling and signage;
4. Divert roof runoff to vegetated areas before discharge unless the diversion would result in slope instability or damage building foundations; and
5. Direct surface flow to vegetated areas before discharge, unless the diversion would result in slope instability or damage building foundations.
B. Street and road construction of ten thousand (10,000) square feet or more of impervious surface shall follow USEPA guidance regarding Managing Wet Weather with Green Infrastructure: Green Streets (December 2008 EPA-833-F-08-009) to the maximum extent practicable.
C. All other planning priority projects shall prepare a LID plan to comply with the following:
1. Retain stormwater runoff on site for the stormwater quality design volume (SWQDv) defined as the runoff from:
a. The eighty-fifth percentile twenty-four (24) hour runoff event as determined from the Los Angeles County eighty-fifth percentile precipitation isohyetal map; or
b. The volume of runoff produced from a seventy-five-hundredths (0.75) inch, twenty-four (24) hour rain event, whichever is greater.
2. Minimize hydromodification impacts to natural drainage systems, as defined in the municipal NPDES permit, as described below:
a. Projects disturbing an area greater than one (1) acre but less than fifty (50) acres must demonstrate the project is designed to retain on site, through infiltration, evapotranspiration, and/or harvest and use, the stormwater volume from the runoff of the ninety-fifth percentile, twenty-four (24) hour storm event, or the runoff flow rate, volume, velocity, and duration for the post-development condition for the two (2) year, twenty-four (24) hour rainfall event; or
b. Projects disturbing fifty (50) acres or more must demonstrate the project infiltrates on site at least the runoff from a two (2) year, twenty-four (24) hour storm event, or the runoff flow rate, volume, velocity, and duration for the post-development condition for the two (2) year, twenty-four (24) hour rainfall event. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.190 Violations.
A. Violation of any provision of this chapter shall be both a misdemeanor and a public nuisance.
B. The remedies specified in this chapter shall not exclude any other legal remedy that may be available to the City. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.200 Inspections.
A. The City Engineer and such officers as the City Engineer may designate shall enforce the provisions of this chapter.
B. As necessary, these officers may, at a reasonable time and in a manner authorized by the laws of California, enter and make inspections on any property regulated under this chapter. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.210 Fees.
The City Council may establish and fix the amount of fees for services provided under this chapter, as authorized under Sections 66016 and 66018 of the California Government Code and this code. (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)
17.95.220 Alternative Compliance—Technical Infeasibility.
When, as determined by the City Engineer or his/her appointee, one hundred percent (100%) on-site retention of the SWQDv is technically infeasible, partially or fully, the infeasibility shall be demonstrated in the submitted LID plan. The technical infeasibility may result from conditions that may include, but are not limited to:
A. The infiltration rate of saturated in-situ soils is less than three-tenths (0.3) inch per hour, and it is not technically feasible to amend the in-situ soils to attain an infiltration rate necessary to achieve reliable performance of infiltration or bioretention BMPs in retaining the SWQDv on site;
B. Locations where seasonal high groundwater is within five (5) to ten (10) feet of surface grade;
C. Locations within one hundred (100) feet of a groundwater well used for drinking water;
D. Brownfield development sites or other locations where pollutant mobilization is a documented concern;
E. Locations with potential geotechnical hazard;
F. Smart growth and infill or redevelopment locations, where the density and/or nature of the project would create significant difficulty for compliance with the on-site volume retention requirement.
If partial or complete on-site retention is technically infeasible, the project site may biofiltrate one and one-half (1.5) times the portion of the remaining SWQDv that is not reliably retained on site. Biofiltration BMPs must adhere to the design specifications provided in the municipal NPDES permit.
1. Additional alternative compliance options, such as off-site infiltration, may be available to the project site. The project site should contact the City Engineer or his/her appointee to determine eligibility. Alternative compliance options are further specified in the Los Angeles County 2014 Low Impact Development Standards Manual (2014 LID Standards Manual).
G. The remaining SWQDv that cannot be retained or biofiltered on site must be treated to reduce pollutant loading. BMPs must be selected and designed to meet pollutant-specific benchmarks as required per the municipal NPDES permit. Flow-through BMPs may be used to treat the remaining SWQDv and must be sized based on a rainfall intensity of:
1. Two-tenths (0.2) inches per hour, or
2. The one (1) year, one (1) hour rainfall intensity as determined from the most recent Los Angeles County isohyetal map, whichever is greater.
H. A multi-phased project may comply with the standards and requirements of this section for all of its phases by: (1) designing a system acceptable to the City Engineer to satisfy these standards and requirements for the entire site during the first phase, and (2) implementing these standards and requirements for each phase of development or redevelopment of the site during the first phase or prior to commencement of construction of a later phase, to the extent necessary to treat the stormwater from such later phase. For purposes of this section, “multi-phased project” shall mean any planning priority project implemented over more than one (1) phase and the site of a multi-phased project shall include any land and water area designed and used to store, treat, or manage stormwater runoff in connection with the development or redevelopment, including any tracts, lots, or parcels of real property, whether developed or not, associated with, functionally connected to, or under common ownership or control with such development or redevelopment. (Source: Order No. R4-2012-0175.) (Ord. 13-8 § 4 (Exh. A), 6/11/13; Ord. 15-4 § 1, 5/26/15)