Chapter 13.10 COMPREHENSIVE DRAINAGE PLAN

Chapter 13.10
COMPREHENSIVE DRAINAGE PLAN

Sections:

13.10.010 Comprehensive drainage plan permit procedures and requirements.

13.10.020 Exceptions to on-site stormwater management requirements – Exceptions for providing stormwater management.

13.10.030 General and technical criteria for stormwater management.

13.10.040 General and technical criteria for erosion and sediment control.

13.10.050 Construction inspection provisions.

13.10.060 Maintenance and repair of stormwater facilities.

13.10.010 Comprehensive drainage plan permit procedures and requirements.

(1) For the purposes of this section, when land-disturbing activity will be required of a contractor performing work pursuant to a construction contract, the preparation, submission and approval of a comprehensive drainage plan and/or an erosion and sediment control plan shall be the responsibility of the owner of the land upon which activity takes place.

(2) Except as provided in Section 62.1-44.15:56 and Section 62.1-44.15:31 of the Code of Virginia, as may be amended (state agency projects), no person may engage in any land-disturbing activity (except as provided under SCC 13.05.040) until submitting to the administrator a comprehensive drainage plan for the land-disturbing activity and such plan having been approved by the administrator and a VSMP permit or VESCP permit issued therefor.

(3) Where the land-disturbing activity results from the construction of a single-family residence, at the discretion of the administrator, an agreement in lieu of an erosion and sediment control plan and/or an agreement in lieu of a stormwater management plan may be permitted.

(4) No land owner shall receive any of the building, grading or other land development permits required for land-disturbance activities without first meeting the requirements of Division I of this title prior to commencing the proposed activity.

(5) Other city agencies authorized under any other law to issue grading, building or other permits for activities involving land-disturbing activities may not issue any such permit unless the applicant submits with the application an approved comprehensive drainage plan and certification that the plan will be followed.

(6) Should a land-disturbing activity associated with an approved plan in accordance with this section not begin within 180 days following approval or cease for more than 180 days, the administrator may evaluate the approved comprehensive drainage plan to determine whether the plan still satisfies the requirements of Division I of this title and to verify that all design factors are still valid. If the administrator finds the previously filed plan to be inadequate, a modified plan must be submitted and approved prior to the resumption of land-disturbing activities.

(7) Application Requirements. Unless specifically excluded or exempted by Division I of this title, any landowner desiring a VSMP permit or a VESCP permit for a land-disturbance activity shall submit a comprehensive drainage plan to the administrator for review and approval. Applications shall be accompanied by the following:

(a) VSMP general permit registration statement;

(b) VESCP permit application;

(d) Seven copies of the stormwater management final plan and previously approved concept plan, if required, in accordance with subsections (11) through (13) of this section and SCC 13.10.030;

(e) Seven copies of the erosion and sediment control plan in accordance with subsection (15) of this section and SCC 13.10.040;

(f) Seven copies of the stormwater pollution prevention plan in accordance with subsection (10) of this section (required for VSMP permits only);

(g) Seven copies of the pollution prevention plan in accordance with subsection (14) of this section (required for VSMP permits only); and

(h) Two copies of the stormwater management inspection and maintenance agreement documents in accordance with this section and SCC 13.10.060.

(8) No application for land development, land use conversion, land disturbance, or redevelopment will be approved unless it includes a comprehensive drainage plan, as required by Division I of this title, detailing how runoff and associated water quality and quantity impacts resulting from the activity will be controlled or managed.

(9) No building, grading, VSMP or VESCP permit shall be issued until a satisfactory comprehensive drainage plan, or a waiver thereof, has undergone a review and is approved by the administrator after determining that the plan or waiver is consistent with the requirements of Division I of this title.

(10) Stormwater Pollution Prevention Plan (SWPPP) Required.

(a) The stormwater pollution prevention plan (SWPPP) shall include the content specified in 9 VAC 25-870-54 of the VSMP Permit Regulations and must also comply with the requirements and general information set forth in 9 VAC 25-880-70, Section II (stormwater pollution prevention plan) of the general permit. Such requirements shall include, but not be limited to, the following:

(i) An approved erosion and sediment control plan in accordance with subsection (15) of this section and SCC 13.10.040;

(ii) An approved stormwater management plan in accordance with subsections (11) through (13) of this section and SCC 13.10.030;

(iii) An approved pollution prevention plan for regulated land-disturbing activities in accordance with subsection (14) of this section; and

(iv) A description of any additional control measures necessary to address a TMDL in accordance with subsection (16) of this section.

(b) The SWPPP shall be amended by the operator whenever there is a change in design, construction, operation, or maintenance that has a significant effect on the discharge of pollutants to state waters which is not addressed by the existing SWPPP.

(c) The SWPPP must be maintained by the operator at a central location on site. If an on-site location is unavailable, notice of the SWPPP’s location must be posted near the main entrance at the construction site. Operators shall make the SWPPP available for public review in accordance with Section II of the general permit, either electronically or in hard copy.

(11) Stormwater Management Concept and Final Plan Required. For newly developed projects which are being or will be developed in more than one phase, including all major subdivisions, a stormwater management plan shall consist of a concept plan for all phases of development and a final plan for the phase(s) submitted for permitting to ensure adequate planning for the management of stormwater runoff. All developments, except those exempted by Division I of this title, shall provide a final stormwater management plan. Both plans shall be in accordance with the criteria established in this section and SCC 13.10.030.

(12) Stormwater Management Concept Plan Required. A stormwater management concept plan shall include all information as required by this chapter in order to evaluate the environmental characteristics of the planning area, the potential impacts of all proposed development of the site, both present and future, on the water resources, and the effectiveness and acceptability of the measures proposed for managing stormwater generated at the project site.

(a) The concept plan should be prepared at the time of the preliminary plan of subdivision or other early step in the development process to identify the type of stormwater management measures necessary for the proposed project. The intent of this conceptual planning process is to ensure adequate planning for management of stormwater runoff from future development. To accomplish this goal, the following information shall be included in the concept plan:

(i) A map or maps indicating the location of existing and proposed buildings, roads, parking areas, utilities, riparian buffers, integrated management practices, structural stormwater management and existing two-foot contours. The map(s) shall also clearly show proposed land use, drainage patterns and boundaries and the limits of clearing and grading. The map(s) shall be at a minimum scale of one inch equals 100 feet.

(ii) A written description of the site plan and justification of proposed changes in natural conditions.

(iii) A written or graphic inventory of the natural resources at the site and surrounding area as it exists prior to the commencement of the project and a description of the watershed and its relation to the project site.

(iv) Existing Tree and Vegetation Plan. The plan shall include the following for the entire project area:

(A) The outline of existing masses of vegetation. Forested areas shall be separately identified.

(B) Description of Existing Conditions. A narrative shall describe the quality of the existing vegetation and the impacts of the development on the vegetation.

(C) Description of Preservation Strategies. A narrative shall be provided to describe strategies for preservation and protection of existing vegetation to remain.

(b) The city requires a concept plan to consider the maximum development potential of a site under existing zoning, regardless of whether the applicant presently intends to develop the site to its maximum potential.

(c) The applicant may be required to include within the stormwater concept plan measures for controlling existing stormwater runoff discharges from development or redevelopment occurring on a previously developed site in accordance with the standards of Division I of this title to the maximum extent practicable.

(13) Final Stormwater Management Plan Required. After review of the stormwater management concept plan, if required, and modifications to the concept plan as deemed necessary by the administrator, a final stormwater management plan must be submitted for approval.

(a) Final stormwater management plans must apply the stormwater management general and technical criteria set forth in subsections (11) through (13) of this section and in SCC 13.10.030 to the entire land-disturbing activity. Individual lots in new residential, commercial or industrial developments shall not be considered separate land-disturbing activities.

(b) The stormwater management plan shall consider all sources of surface runoff and all sources of subsurface and groundwater flows converted to subsurface runoff.

(c) The final stormwater management plan, in addition to the information from the concept plan, shall include the following:

(i) Information on the type and location of stormwater discharges; information on the features to which stormwater is being discharged including surface waters or karst features, if present, and the pre-development and post-development drainage areas;

(ii) Contact information including the name, address, and telephone number of all persons having a legal interest in the property and the tax reference number, zoning, use and parcel number of the project property or properties, adjacent properties and other properties affected by the project, including reference to any immediately prior source deed for title to the property;

(iii) A narrative that includes a description of current site conditions and final site conditions;

(iv) A general description of the proposed stormwater management facilities and the mechanism through which the facilities will be operated and maintained after construction is complete;

(v) Information on the proposed stormwater management facilities, including:

(A) The type of facilities;

(B) Location, including geographic coordinates;

(D) The surface waters or karst features, if present, into which the facility will discharge;

(vi) Hydrologic and hydraulic computations, including runoff characteristics and the following information:

(A) Description of the design storm frequency, including intensity and duration;

(B) Time of concentration path shown on pre- and post-development drainage maps, to a common design point and labeled with type of flow, length and slope;

(D) Pre-development and post-development peak runoff rates and total runoff volumes for each drainage area;

(E) Infiltration rates, where applicable;

(F) Culvert capacities;

(G) Flow velocities;

(H) Data on the increase in rate and volume of runoff for the specified design storms;

(I) Documentation of sources for all computation methods and field test results;

(J) A table summarizing the calculations for each structural stormwater management and erosion control facility; and

(K) A summary table showing the pre-development and post-development drainage areas, peak runoff rates, and velocities for all required storm frequencies at each discharge point shall be provided on the final stormwater management plan;

(vii) Documentation and calculations verifying compliance with the water quality and quantity requirements of SCC 13.10.030;

(viii) A map or maps of the site that depicts the topography of the site and includes:

(A) All contributing drainage areas;

(B) Existing streams, ponds, culverts, ditches, wetlands, other water bodies, and floodplains;

(D) Current land use including existing structures, roads, and locations of known utilities and easements;

(E) Sufficient information on adjoining parcels to assess the impacts of stormwater from the site on these parcels;

(F) The limits of clearing and grading, and the proposed drainage patterns on the site;

(G) Proposed buildings, roads, parking areas, utilities, riparian buffers, integrated management practices, stormwater management facilities and sediment control facilities;

(H) Proposed land use with tabulation of the percentage of surface area to be adapted to various uses, including but not limited to planned locations of utilities, roads, and easements;

(I) Topographic base map of the site shall be at a minimum scale of one inch equals 100 feet and extend a minimum of 100 feet beyond the limits of the proposed development; and

(J) Existing and proposed two-foot contours with spot elevations at critical locations, including corners of pavement edges;

(ix) Soils Information. Geotechnical properties for the hydrologic and structural properties of soils, especially for dam embankments, shall be described in a soils report. The submitted report shall include boring depth, sampling frequency and types and associated laboratory testing with results and conclusions and follow the criteria in the Virginia Stormwater Management Handbook. Soil properties for infiltration facilities shall also conform to the guidance and specifications outlined in the Virginia Stormwater Management Handbook and the Virginia Stormwater Management BMP Clearinghouse website;

(x) Stormwater Planting Plan. The landscape plans shall be prepared and stamped by a registered professional engineer or landscape architect licensed in the Commonwealth of Virginia.

(A) This plan must be prepared by a qualified individual familiar with the selection of emergent and upland vegetation appropriate for the selected BMP.

(B) The city encourages the use of a vegetation strategy that can produce an aesthetically pleasing, compatible with its surroundings, facility while simultaneously augmenting pollutant removal capabilities and wildlife habitat. The Virginia Stormwater Management Handbook provides guidance in the plant selection and planting zone location for both within and surrounding the stormwater management facility;

(xi) Other Environmental Permits. The applicant shall assure that all other applicable environmental permits have been applied for prior to issuance of the site construction permit.

(d) If an operator intends to meet the water quality and/or quantity requirements set forth in SCC 13.10.030 through the use of off-site compliance options, where applicable, then a letter of availability from the off-site provider must be included. Approved off-site options must achieve the necessary nutrient reductions prior to the commencement of the applicant’s land-disturbing activity except as otherwise allowed by Section 62.1-44.15:35 of the Code of Virginia.

(e) Elements of the final stormwater management plan that include activities regulated under Chapter 4 (Section 54.1-400 et seq.) of Title 54.1 of the Code of Virginia shall be appropriately sealed and signed by a professional registered in the Commonwealth of Virginia pursuant to Article 1 (Section 54.1-400 et seq.) of Chapter 4 of Title 54.1 of the Code of Virginia.

(f) A construction record drawing for permanent stormwater management facilities shall be submitted to the administrator. The construction record drawing shall be appropriately sealed and signed by a professional registered in the Commonwealth of Virginia, certifying that the stormwater management facilities have been constructed in accordance with the approved plan.

(14) Stormwater Pollution Prevention Plan (PPP) Required.

(a) Pollution Prevention Plan, required by 9 VAC 25-870-56 of the VSMP Permit Regulations, shall be developed, implemented, and updated as necessary and must detail the design, installation, implementation, and maintenance of effective pollution prevention measures to minimize the discharge of pollutants. At a minimum, such measures must be designed, installed, implemented, and maintained to:

(i) Minimize the discharge of pollutants from equipment and vehicle washing, wheel wash water, and other wash waters. Wash waters must be treated in a sediment basin or alternative control that provides equivalent or better treatment prior to discharge;

(ii) Minimize the exposure of building materials, building products, construction wastes, trash, landscape materials, fertilizers, pesticides, herbicides, detergents, sanitary waste, and other materials present on the site to precipitation and to stormwater; and

(iii) Minimize the discharge of pollutants from spills and leaks and implement chemical spill and leak prevention and response procedures.

(b) The pollution prevention plan shall include effective best management practices to prohibit the following discharges:

(i) Wastewater from washout of concrete, unless managed by an appropriate control;

(ii) Wastewater from washout and cleanout of stucco, paint, form release oils, curing compounds, and other construction materials;

(iii) Fuels, oils, or other pollutants used in vehicle and equipment operation and maintenance; and

(iv) Soaps or solvents used in vehicle and equipment washing.

(c) Discharges from dewatering activities, including discharges from dewatering of trenches and excavations, are prohibited unless managed by appropriate controls.

(15) Erosion and Sediment Control Plan Required. All erosion and sediment control plans and reports shall be appropriately sealed and signed by a professional engineer licensed in Virginia, in adherence to all minimum standards and requirements pertaining to the practice of that profession in accordance with Virginia Erosion and Sediment Control Regulations, certifying that the plan meets all submittal requirements outlined in Division I of this title and is consistent with good engineering practice.

(a) The erosion and sediment control plan(s) and narrative shall include all of the information required in the Checklist for Erosion and Sediment Control Plans and Narrative and the Minimum Standards Checklist found in the Virginia Erosion and Sediment Control Handbook. Both checklists shall be submitted with the erosion and sediment control plan.

(b) The documentation shall follow the format and conform to the approved standards and specifications for control techniques as set forth in the Virginia Erosion and Sediment Control Handbook, which by reference is adopted as a part of Division I of this title. The plan shall be consistent with the criteria, techniques and methods as set forth in the Minimum Standards (9 VAC 25-840-40) of the Virginia Erosion and Sediment Control Regulations adopted by the State Board.

(16) Additional Control Measures to Address a TMDL Required. In addition to the requirements of SCC 13.10.010 through 13.10.040, if a specific WLA for a pollutant has been established in a TMDL and is assigned to stormwater discharges from a construction activity, additional control measures must be identified and implemented by the operator so that discharges are consistent with the assumptions and requirements of the WLA in a State Water Control Board-approved TMDL.

(17) Stormwater Management Inspection and Maintenance Agreements.

(a) The administrator shall require the provision of long-term responsibility for and maintenance of stormwater management facilities and other techniques specified to manage the quality and quantity of runoff. Such requirements shall be set forth in an instrument recorded in the local land records prior to general permit termination, VESCP authority permit termination or earlier as required by the administrator and shall at a minimum:

(i) Be submitted to the administrator for review and approval prior to the approval of the stormwater management plan;

(ii) Be stated to run with the land;

(iii) Provide for all necessary access to the property for purposes of maintenance and regulatory inspections;

(iv) Provide for inspections and maintenance and the submission of inspection and maintenance reports to the administrator; and

(v) Be enforceable by all appropriate governmental parties.

(b) A copy of the recorded agreement shall be submitted to the administrator.

(c) The inspection and maintenance agreement shall be prepared, executed and submitted to the city in the form currently provided by the city engineering department, as revised from time to time.

(d) At the discretion of the administrator, such recorded instruments need not be required for stormwater management facilities designed to treat stormwater runoff primarily from an individual residential lot on which they are located, provided it is demonstrated to the satisfaction of the administrator that future maintenance of such facilities will be addressed through an enforceable mechanism at the discretion of the administrator.

(e) If a recorded instrument is not required pursuant to subsection (17)(d) of this section, the applicant shall develop a strategy for addressing maintenance of stormwater management facilities designed to treat stormwater runoff primarily from an individual residential lot on which they are located. Such a strategy may include periodic inspections, homeowner outreach and education, or other method targeted at promoting the long-term maintenance of such facilities. Such facilities shall not be subject to the requirement for an inspection to be conducted by the administrator. This strategy shall be submitted to the administrator for review and approval prior to issuance of a VSMP permit or VESCP permit. (Ord. 2014-09; Ord. 2009-09; Ord. 2007-30; Ord. 2007-20. Code 1985, § 11-20).

13.10.020 Exceptions to on-site stormwater management requirements – Exceptions for providing stormwater management.

(1) The minimum requirements for stormwater management may be waived, in whole or in part, upon written request of the applicant; provided, that at least one of the following conditions applies:

(a) It can be demonstrated that the proposed development is not likely to impair attainment of the objectives of Division I of this title;

(b) Alternative minimum requirements for on-site management of stormwater discharges are established in a stormwater management plan that was previously approved by the administrator;

(c) Provisions are made to manage stormwater by an off-site facility. Off-site facilities shall be in accordance with 9 VAC 25-870-69 of the VSMP Permit Regulations. The off-site facility is required to be designed and adequately sized to provide a level of stormwater control that is equal to or greater than that which would be afforded by on-site practices and to be constructed prior to the on-site land development activity. The owner shall designate a legally obligated entity responsible for long-term operation and maintenance of the stormwater practice; or

(d) The administrator finds that meeting the minimum on-site management requirements is not feasible due to the natural or existing physical characteristics of a site.

(e) Economic hardship is not sufficient reason to grant an exception from the requirements of Division I of this title.

(2) The administrator grants a waiver from strict compliance with stormwater management provisions that are not achievable, only if acceptable mitigation measures are provided. However, to be eligible for a waiver, the applicant must demonstrate to the satisfaction of the administrator that the immediately downstream waterways will not be subject to:

(a) Deterioration of existing culverts, bridges, dams, and other structures;

(b) Deterioration of biological functions or habitat;

(d) Increased threat of flood damage to public health, life and property.

(3) If the waiver request meets all of the above conditions and is acceptable to the administrator, the administrator shall approve the waiver.

(4) Off-Site Stormwater Management Facilities. In lieu of providing on-site stormwater management, an applicant may obtain a waiver of the required stormwater management by entering into an agreement with the city for the granting of an easement or the dedication of land by the applicant to be used for the construction of an off-site stormwater management facility. Off-site stormwater management facilities shall be in accordance with 9 VAC 25-870-69 of the VSMP Permit Regulations. The applicant must provide calculations to the administrator showing that an adequate stormwater conveyance system exists or will be provided to convey the stormwater runoff from the development to an off-site facility. The agreement shall be entered into by the applicant and the city prior to the recording of plats or, if no record plat is required, prior to the issuance of the building permit. (Ord. 2014-09; Ord. 2009-09; Ord. 2007-20. Code 1985, § 11-21).

13.10.030 General and technical criteria for stormwater management.

The following general and technical criteria shall apply to land development and land-disturbance activities which require a VSMP permit and/or a VESCP permit. In the event of conflict between any of these criteria, the most stringent shall govern.

(1) To protect the quality and quantity of state water from the potential harm of unmanaged stormwater runoff resulting from land-disturbing activities, the city hereby adopts the technical criteria for regulated land-disturbing activities set forth in this section and Part II B of the Virginia Stormwater Management Program (VSMP) Permit Regulations, as may be amended, expressly to include:

(a) 9 VAC 25-870-62 (applicability);

(b) 9 VAC 25-870-63 (water quality design criteria requirements);

(d) 9 VAC 25-870-66 (water quantity);

(e) 9 VAC 25-870-69 (off-site compliance options);

(f) 9 VAC 25-870-72 (design storms and hydrologic methods);

(g) 9 VAC 25-870-74 (stormwater harvesting);

(h) 9 VAC 25-870-76 (linear development project);

(i) 9 VAC 25-870-85 (stormwater management impoundment structures or facilities); and

(j) 9 VAC 25-870-92 (comprehensive stormwater management plans);

which shall apply to all land-disturbing activities regulated pursuant to this title, except as expressly set forth in subsection (2) of this section.

(2) Any land-disturbing activity shall be considered grandfathered by the VSMP authority and shall be subject to the Part II C technical criteria of the VSMP Permit Regulations provided:

(a) A proffered or conditional zoning plan, zoning with a plan of development, preliminary or final subdivision plat, preliminary or final site plan or any document determined by the locality to be equivalent thereto:

(i) Was approved by a locality prior to July 1, 2012;

(ii) Provided a layout as defined in 9 VAC 25-870-10;

(iii) Will comply with the Part II C technical criteria of the VSMP Permit Regulations; and

(iv) Has not been subsequently modified or amended in a manner resulting in an increase in the amount of phosphorus leaving each point of discharge, and such that there is no increase in the volume or rate of runoff;

(b) A state permit has not been issued prior to July 1, 2014; and

(3) Locality, state and federal projects shall be considered grandfathered by the VSMP authority and shall be subject to the Part II C technical criteria of the VSMP Permit Regulations provided:

(a) There has been an obligation of locality, state or federal funding, in whole or in part, prior to July 1, 2012, or the department has approved a stormwater management plan prior to July 1, 2012;

(b) A state permit has not been issued prior to July 1, 2014; and

(4) Land-disturbing activities grandfathered under subsections (2) and (3) of this section shall remain subject to the requirements set forth in this section and the Part II C technical criteria of the Virginia Stormwater Management Program (VSMP) Permit Regulations, 9 VAC 25-870-93 through 9 VAC 25-870-99, for one additional state permit cycle. After that time, portions of the project not under construction shall become subject to any new technical criteria adopted by the State Board.

(5) In cases where governmental bonding or public debt financing has been issued for a project prior to July 1, 2012, such project shall be subject to the technical criteria of Part II C of the VSMP Permit Regulations.

(6) The administrator may grant exceptions to the technical requirements of Part II B or Part II C of the VSMP Permit Regulations; provided, that (a) the exception is the minimum necessary to afford relief, (b) reasonable and appropriate conditions are imposed so that the intent of the Virginia Stormwater Management Act, the Virginia Stormwater Management Program (VSMP) Permit Regulations, and this title are preserved, (c) granting the exception will not confer any special privileges that are denied in other similar circumstances, and (d) exception requests are not based upon conditions or circumstances that are self-imposed or self-created. Economic hardship alone is not sufficient reason to grant an exception from the requirements of this title.

(a) Exceptions to the requirement that the land-disturbing activity obtain required VSMP authority permit shall not be given by the administrator, nor shall the administrator approve the use of a BMP not found on the Virginia Stormwater BMP Clearinghouse website, or any other control measure duly approved by the director.

(b) Exceptions to requirements for phosphorus reductions shall not be allowed unless off-site options otherwise permitted pursuant to 9 VAC 25-870-69 of the VSMP Permit Regulations have been considered and found not available.

(7) Nothing in this section shall preclude an operator from constructing to a more stringent standard at their discretion.

(8) General Criteria.

(a) Proposed residential, commercial, or industrial subdivisions shall apply the stormwater management criteria provided in this section to the land development as a whole, including submission, review and approval of a stormwater management concept plan reflecting all proposed lots in the ultimate developed condition.

(b) Use of nonstructural stormwater practices (low-impact development) as part of the site layout and design for all developments and redevelopments is required in order to reduce the amount of stormwater runoff that must be managed. This will help to minimize the reliance on structural practices which require ongoing maintenance in order to be effective.

(c) On-site stormwater conveyance systems shall be designed for the 10-year storm event. Closed storm sewer systems shall be designed such that the hydraulic grade line for the 10-year storm event is a maximum elevation of one foot below the throat of the inlet.

(d) Determination of flooding and channel erosion impacts to receiving streams due to land development projects shall be measured at each point of discharge from the development project and such determination shall include any runoff from the balance of the watershed that also contributes to that point of discharge.

(e) Stormwater runoff shall be calculated by the following methods unless an alternative method for a specific project has been approved by the administrator:

(i) U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS) synthetic 24-hour rainfall distribution and models, including, but not limited to, TR-55 and TR-20; hydrologic and hydraulic methods developed by the U.S. Army Corps of Engineers; or other standard hydrologic and hydraulic methods.

(ii) The rational method may be used for evaluating peak discharges to stormwater conveyances where the contributing drainage area is 20 acres or less.

(iii) The modified rational (critical storm duration) method may be used for evaluating volumetric flows to stormwater conveyances where the contributing drainage area is 20 acres or less.

(f) The rainfall rates for all calculations shall be as provided in the U.S. National Oceanic and Atmospheric Administration (NOAA) publication “Atlas 14: Rainfall Precipitation Frequency Data,” latest edition.

(g) For purposes of computing predevelopment runoff, all pervious lands on the site shall be assumed to be in good hydrologic condition in accordance with the U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS) standards, regardless of conditions existing at the time of computation. Predevelopment runoff calculations utilizing other hydrologic conditions may be utilized; provided, that it is demonstrated to and approved by the VSMP authority that actual site conditions warrant such considerations.

(h) Pre-development and post-development runoff characteristics and site hydrology shall be verified by site inspections, topographic surveys, available soil mapping or studies, and calculations consistent with good engineering practices. Guidance provided in the Virginia Stormwater Management Handbook and by the Virginia Stormwater BMP Clearinghouse shall be considered appropriate practices.

(i) Stormwater management facilities and best management practices shall be designed and sited to capture, to the maximum extent practicable, the runoff from the entire land development project area and, in particular, areas of impervious cover within the development project area. If the entire land development cannot be captured by the stormwater management facilities, the facilities shall be sized so that the addition of the peak release rate from the facility(ies) individually and the undetained areas within the same watershed do not exceed the requirements of Division I of this title.

(j) The number, type, and siting of stormwater management facilities shall be designed so as to preserve natural channel characteristics, existing vegetation, and natural groundwater recharge on a site to the extent practical.

(k) Outflows from a stormwater management facility shall be discharged to a stormwater conveyance system, and velocity dissipaters shall be placed at the outfall of all stormwater management facilities and along the length of any outfall channel as necessary to provide a nonerosive velocity of flow from the basin to a channel. A karst feature, whether on site or downstream and off site, may only be considered an adequate receiving channel if design criteria are in compliance with the criteria in subsections (8)(m) and (n) of this section.

(l) Construction of stormwater management facilities or modifications to channels shall comply with all applicable laws and regulations. Evidence of approval of all necessary permits, such as U.S. Army Corps of Engineers and VA DEQ Wetland Permits, VA DEQ VPDES Permits, etc., shall be provided prior to beginning construction.

(m) Construction of stormwater management impoundment structures or facilities may occur in karst areas only after a geological study of the area is conducted supporting the compatibility of such structures. A karst feature may only be filled or “improved” in accordance with proper geotechnical design (see VDOT IIM-228).

(n) No adverse environmental impacts shall occur to any identified karst features. Discharge of stormwater into a karst feature shall not occur unless the pretreatment and water quality criteria are met. Increased volumes of stormwater runoff to a karst feature shall not occur.

(o) Impounding structures that are not covered by the Virginia Impounding Structures Regulations (Dam Safety) shall be designed and checked for structural integrity and for floodplain impacts for a minimum of the 100-year storm event.

(p) Construction of stormwater management impoundment structures within a Federal Emergency Management Agency (FEMA) designated 100-year floodplain shall be avoided to the extent possible. When this is unavoidable, all stormwater management facility construction shall be in compliance with all applicable regulations under the National Flood Insurance Program, 44 CFR Part 59, and Chapter 18.170 SCC, Floodplain Districts and Regulations, and the Staunton City Code. These SWM facilities shall be designed and located, to the extent practical, to: (i) provide an unrestricted release up to at least the 10-year flood elevation of the receiving state water; and (ii) maintain their water quantity and/or water quality control value during the 100-year flood condition.

(9) Stormwater Management Facilities.

(a) Minimum Control Requirements.

(i) All stormwater management practices shall be designed so that the specific storm frequency storage volumes as identified in Division I of this title and the current Virginia Stormwater Management Handbook, whichever is more stringent, are met, unless the administrator grants the applicant a waiver or the applicant is exempt from such requirements.

(ii) In addition, if hydrologic or topographic conditions warrant greater control than that provided by the minimum control requirements, the administrator reserves the right to impose any and all additional requirements deemed necessary to protect downstream properties and aquatic resources from damage due to increased volume, frequency, velocity, and rate of stormwater runoff.

(b) Site Design Feasibility.

(i) Stormwater management practices for a site shall be chosen based on the physical conditions of the site. Among the factors that should be considered are as follows:

(A) Topography.

(B) Existing vegetation.

(D) Depth to water table.

(E) Soils.

(F) Slopes.

(G) Terrain.

(H) Hydraulic head.

(I) Location in relation to environmentally sensitive features.

(J) Intended or proposed land use.

(K) Karst features.

(L) Depth to rock.

(ii) Applicants shall consult the Virginia Stormwater Management Handbook for guidance on the factors that determine site design feasibility when selecting a stormwater management practice.

(i) All stormwater management practices shall be designed to convey stormwater to allow for the maximum removal of pollutants and reduction in flow velocities. This shall include, but not be limited to:

(A) Maximizing of flowpaths from inflow points to outflow points;

(B) Protecting of inlet and outfall structures;

(D) Providing of under-drain systems, where applicable and appropriate;

(E) Incorporating appropriate BMPs in consideration of site-specific conditions.

(ii) The Virginia Stormwater Management Handbook and the Virginia Stormwater BMP Clearinghouse provides detailed references on the requirements for conveyance for each of the approved stormwater management practices.

(d) Pretreatment Requirements. Every stormwater treatment practice shall have an acceptable form of water quality pretreatment, in accordance with the pretreatment requirements found in the current Virginia Stormwater Management Handbook. Stormwater infiltration practices or practices having an infiltration component, as specified in the Virginia Stormwater Management Handbook, are prohibited, even with pretreatment, in the following circumstances:

(i) Where stormwater is generated from highly contaminated source areas known as “hotspots”;

(ii) Where stormwater is carried in a conveyance system that also carries contaminated, nonstormwater discharges;

(iii) Where stormwater is being managed in a designated groundwater recharge area; or

(iv) Under certain geologic conditions (e.g., karst) that prohibit the proper pretreatment of stormwater.

(e) Treatment/Geometry Conditions.

(i) All stormwater management practices shall be designed to capture and treat stormwater runoff according to the specifications outlined in the Virginia Stormwater Management Handbook. These specifications will designate the water quality treatment and water quantity criteria that apply to an approved stormwater management practice as required by Division I of this title.

(ii) Stormwater management facilities shall be designed to conform to the natural topography where practical.

(iii) Any detention facilities that are designed to have a permanent pool of water constructed in or adjacent to residential and commercial zoning areas shall be constructed with an aquatic bench or have a minimum of a six-foot fence installed around the perimeter of the facility.

(10) Nonstructural Stormwater Quantity and Quality Control (Low-Impact Development – LID).

(a) The use of LID site planning and integrated management practices is required by the city for all developments and redevelopments to control stormwater runoff at the source and more closely approximate pre-development runoff conditions.

(b) LID stormwater management design plans developed consistent with the requirements of this subsection shall satisfy the water quality and quantity performance criteria of Division I of this title.

(c) The design criteria, hydrologic analysis and computational procedures for LID stormwater management design plans shall be in accordance with the Virginia Stormwater Management Handbook and the Virginia Stormwater BMP Clearinghouse.

(d) LID stormwater management design plans shall not conflict with existing federal, state or local laws, ordinances, regulations or policies.

(e) Stormwater management inspection and maintenance agreement documentation, as provided by SCC 13.10.010(17), shall be recorded to identify the locations of integrated management practices on lots or parcels. The owner shall not remove or structurally alter integrated management practices without prior written approval from the city.

(f) Developments shall, to the extent practicable, incorporate LID practices in accordance with the Virginia Stormwater Management Handbook and the Virginia Stormwater BMP Clearinghouse into the site layout and design to minimize increases in runoff rates, volumes, and pollutant loads.

(g) In addition, the following LID practices are required to be incorporated into each project:

(i) Disconnect Impervious Areas/Downspout Disconnection. All runoff from rooftops shall be directed onto vegetated swales or filter strips prior to entering a closed storm sewer system.

(ii) Disconnected impervious areas shall be treated as close as practical to their source, and not at the low point of the site just prior to entering the public drainage system, unless that is the only possible location for treatment.

(iii) Site Minimization/Impervious Areas Reduction.

(A) Minimal ground disturbance shall be achieved by identifying the smallest possible land area that can practically be impacted during site development.

(B) Development should be placed away from environmentally sensitive areas, future open space, tree preservation areas, future restoration areas, and temporary and permanent buffer zones, as required in Chapter 13.12 SCC. Existing vegetated or open space may be preserved instead of clearing a portion of the site in order to create lawn areas. Impervious surface area shall be limited by site designs that minimize the area of streets, parking lots, and rooftops and/or utilize permeable paving material. For residential areas, cluster development shall be provided where appropriate.

(iv) Other best management practices such as individual rain gardens, infiltration basins and trenches (where permeable soils are present) and filtration basins and sand filters (on highly impervious or industrial developments) shall be utilized where appropriate.

(11) Stormwater Water Quality Control. Unless determined by the administrator for a project to be exempt, the following criteria shall be addressed for stormwater management at all sites:

(a) All stormwater runoff generated from land development and land use conversion activities shall not discharge stormwater runoff directly into a wetland or local water body without adequate treatment. Where such discharges are proposed, the impact of the proposal on wetland functions shall be assessed using a method acceptable to the administrator. In no case shall the impact on functions be any more than allowed by the Army Corps of Engineers (ACE) or the Department of Environmental Quality.

(b) Land development projects shall comply with the water quality criteria in accordance with Article 2.3 of Chapter 3.1 of Title 62.1 of the Code of Virginia; 9 VAC 25-870-63 and 9 VAC 25-870-65 of the VSMP Permit Regulations; and the Virginia Stormwater Management Handbook, latest edition; and the Virginia Stormwater BMP Clearinghouse.

(c) Stormwater discharges to critical areas with sensitive resources (i.e., cold water fisheries, impaired streams and tributaries, recreational waters, recharge areas, karst features, water supply reservoirs) may be subject to additional criteria, or may need to utilize or restrict certain stormwater management practices at the discretion of the administrator.

(d) Industrial sites which are listed under the Standard Industrial Code are required to prepare and implement a stormwater pollution prevention plan, and shall file a notice of intent (NOI) under the provisions of the National Pollutant Discharge Elimination System (NPDES) general permit. The stormwater pollution prevention plan requirement applies to both existing and new industrial sites.

(e) Stormwater discharges from land uses or activities with higher potential pollutant loadings, known as “hotspots,” may require the use of specific structural BMPs and pollution prevention practices.

(12) Stormwater Quantity and Velocity Control (Stream Channel Erosion and Flooding).

(a) Calculations for determining peak flows and specific channel protection criteria shall be provided as prescribed in the Virginia Stormwater Management Handbook and Virginia Sediment and Erosion Control Regulations.

(b) Properties and receiving waterways downstream of any land development project shall be protected from erosion and localized flood damage due to increases in volume, velocity and frequency of peak flow rate of stormwater runoff in accordance with the minimum design standards set out in this section.

(c) Channel protection and flood protection shall be addressed in accordance with the minimum standards set out in 9 VAC 25-870-66 of the VSMP Permit Regulations, which are established pursuant to the requirements of subdivision 7 of Section 62.1-44.15:28 of the Code of Virginia. Compliance with the minimum standards set out in 9 VAC 25-870-66 of the VSMP Permit Regulations shall be deemed to satisfy the requirements of subdivision 19 of 9 VAC 25-840-40 (Minimum Standard 19 of the Virginia Erosion and Sediment Control Regulations). The administrator shall require compliance with 9 VAC 25-870-66 of the VSMP Permit Regulations and as modified in this section (whichever is more stringent).

(d) Concentrated stormwater flow leaving a property or stormwater management facility shall be released directly into a stormwater conveyance system and shall meet the criteria in 9 VAC 25-870-66 of the VSMP Permit Regulations. Channel protection requirements for stormwater conveyance systems shall be in compliance with 9 VAC 25-870-66(B) of the VSMP Permit Regulations. Flood protection requirements for stormwater conveyance systems, except where noted below, shall be in accordance with 9 VAC 25-870-66(C) of the VSMP Permit Regulations.

(e) A “level spreader” design shall not be used to exempt a stormwater management facility from subsection (12)(b) of this section.

(f) The 10-year 24-hour post-developed peak rate of runoff from the development site shall not exceed the two-year 24-hour pre-developed peak rate of runoff.

(g) The two-year 24-hour post-development peak rate and velocity of runoff from the development site shall not exceed the one-year 24-hour pre-development peak rate and velocity of runoff.

(h) All emergency spillways shall be designed to accommodate the 100-year 24-hour post-developed peak rate.

(i) If existing natural receiving channels or previously constructed manmade channels or pipes are not adequate, the applicant shall:

(i) Improve the channel to a condition where the channel protection and flood protection requirements of this section are satisfied; or

(ii) Improve the pipe or pipe system to a condition where the post-developed 10-year storm is contained within the appurtenances in accordance with subsection (8)(c) of this section; or

(iii) Provide a combination of channel or pipe improvement, stormwater detention or other measures that is satisfactory to the administrator to comply with the channel protection and flood protection requirements of this section.

(13) The Environmental Protection Agency’s (EPA) Chesapeake Bay Program considers solar panels to be impervious areas for the purposes of performing water quality modeling/calculations for the Chesapeake Bay total maximum daily load. The city of Staunton is a MS4 locality within the Chesapeake Bay Watershed. As such Chesapeake Bay total maximum daily load is to be accounted for with all stormwater management plans for solar projects.

(a) Water Quantity. Solar panels are to be considered unconnected impervious areas when performing post-development water quantity calculations using the hydrologic methods specified in the Virginia Stormwater Management Program Regulation, 9 VAC 25-870-72. Current information regarding the application of unconnected impervious areas can be found in Chapter 9 (Hydrologic Soil-Cover Complexes), Part 630 (Hydrology) of the Natural Resources Conservation Service’s National Engineering Handbook.

(b) Water Quality. Solar panels are to be considered impervious areas when performing post-development water quality calculations using the Virginia Runoff Reduction Method (VRRM). To account for the disconnection of the solar panels from the overall drainage system, the area of the solar panels may be entered into the applicable “simple disconnection” stormwater best management practices section of the VRRM compliance spreadsheet (i.e., 2a – Simple Disconnection to A/B Soils or 2b – Simple Disconnection to C/D Soils).

(c) Alternative Methods. This policy does not prohibit any alternative method. If alternative proposals are made, such proposals will be reviewed and accepted or denied based on their technical adequacy and compliance with the appropriate laws and regulations.

References for Alternative Methods may include:

Ohio Environmental Protection Agency – Guidance on Post-Construction Stormwater Management for Solar Panel Fields – Fact Sheet (epa.ohio.com)

Minnesota Pollution Control Agency – Minnesota Stormwater Manual – Stormwater management for solar projects: https://stormwater.pca.state.mn.us/index.php/Stormwater_management_for_solar_projects_and_determining_compliance_with_the_NPDES_construction_stormwater_permit

(14) Regional Stormwater Management Plans. Applicants shall contact the administrator prior to submitting an application for stormwater management plan approval to determine if a regional stormwater management plan was developed for the applicable watershed in accordance with 9 VAC 25-870-92 of the VSMP Permit Regulations. If such a plan is in existence, the applicant must meet all stormwater management requirements on site in accordance with the provisions of the regional plan and other management provisions as specified by the administrator. (Ord. 2023-18; Ord. 2014-09; Ord. 2009-09; Ord. 2007-30; Ord. 2007-20. Code 1964, § 9A-2; Ord. 2-25-82; Code 1985, § 11-22; Ord. 6-25-92).

13.10.040 General and technical criteria for erosion and sediment control.

The following general and technical criteria shall be applied on all single-family residential construction, applicable land development, and land conversion activities:

(1) Soil Stabilization. Permanent or temporary soil stabilization shall be applied to denuded areas within seven days after final grade is reached on any portion of the site.

(a) Temporary soil stabilization shall be applied within seven days to denuded areas that may not be at final grade but will remain dormant for longer than 14 days.

(b) Permanent stabilization shall be applied to areas that are to be left dormant for more than one year.

(2) Soil Stockpile Stabilization. During construction, soil stockpiles and borrow areas shall be stabilized as noted in subsection (1) of this section or protected with sediment trapping measures. The applicant is responsible for the temporary protection and permanent stabilization of all soil stockpiles on site as well as borrow areas and soil intentionally transported from the project site.

(3) Permanent Stabilization. Permanent vegetative cover shall be established on denuded areas not otherwise permanently stabilized. Permanent vegetation shall not be considered established until a ground cover is achieved that is uniform, mature enough to survive, and will inhibit erosion.

(4) Sediment Basins and Traps. Sediment basins, sediment traps, perimeter dikes, sediment barriers, and other measures intended to trap sediment shall be constructed as a first step in any land-disturbing activity and shall be made functional before upslope land disturbance takes place.

(5) Stabilization of Earthen Structures. Stabilization measures shall be applied to earthen structures such as dams, dikes, and diversions immediately after installation.

(6) Sediment Traps and Sediment Basins. Sediment traps and basins shall be designed and constructed based upon the total drainage area to be served by the trap or basin as follows:

(a) Sediment Traps.

(i) Only control drainage areas less than three acres.

(ii) Minimum storage capacity of 134 cubic yards per acre of drainage area.

(b) Sediment Basins.

(i) Control drainage areas greater than or equal to three acres.

(ii) Minimum storage capacity of 134 cubic yards per acre of drainage area.

(iii) The outfall system shall, at a minimum, maintain the structural integrity of the basin during a 25-year, 24-hour storm.

(7) Cut and Fill Slopes Design and Construction. Cut and fill slopes shall be designed and constructed in a manner that will minimize erosion. Slopes found to be eroding excessively within one year of permanent stabilization shall be provided with additional slope stabilizing measures until the problem is corrected.

(8) Concentrated Runoff Down Slopes. Concentrated runoff shall not flow down cut or fill slopes unless contained within an adequate temporary or permanent channel, flume, or slope drain structure.

(9) Slope Maintenance. Whenever water seeps from a slope face, adequate drainage or other protection shall be provided.

(10) Storm Sewer Inlet Protection. All storm sewer inlets made operable during construction shall be protected so that sediment-laden water cannot enter the stormwater conveyance system without first being filtered/treated to remove sediment.

(11) Stormwater Conveyance Protection. Before newly constructed stormwater conveyance channels or pipes are made operational, adequate outlet protection and any required temporary or permanent channel lining shall be installed in both the conveyance channel and the receiving channel.

(12) Work in Live Watercourse. When work in a live watercourse is performed:

(a) Precautions shall be taken to minimize encroachment, control sediment transport, and stabilize the work area to the greatest extent possible during construction.

(b) Nonerodible material shall be used for the construction of causeways and cofferdams.

(13) Crossing Live Watercourse. When a live watercourse must be crossed by construction vehicles more than twice in any six-month period, a temporary vehicular stream crossing constructed of nonerodible material shall be provided.

(14) Regulation of Watercourse Crossing. All applicable federal, state and local regulations pertaining to working in or crossing live watercourses shall be met.

(15) Stabilization of Watercourse. The bed and banks of a watercourse shall be stabilized immediately after work in the watercourse is completed.

(16) Underground Utility Line Installation. Underground utility lines shall be installed in accordance with the following standards in addition to other applicable criteria:

(a) No more than 500 linear feet of trench may be opened at one time.

(b) Excavated material shall be placed on the uphill side of trenches.

(c) Effluent from dewatering operations shall be filtered or passed through an approved sediment trapping device, or both, and discharged in a manner that does not adversely affect flowing streams or off-site property.

(d) Material used for backfilling trenches shall be properly compacted in order to minimize erosion and promote stabilization.

(e) Restabilization shall be accomplished in accordance with these regulations.

(f) Comply with applicable safety regulations.

(17) Vehicular Sediment Tracking. Where construction vehicle access routes intersect paved or public roads:

(a) Provisions shall be made to minimize the transport of sediment by vehicular tracking onto the paved surface.

(b) Where sediment is transported onto a paved or public road surface, the road surface shall be cleaned thoroughly at the end of each day.

(c) Sediment shall be removed from the roads by shoveling or sweeping and transported to a sediment control disposal area. Street washing shall be allowed only after sediment is removed in this manner.

(18) Removal of Temporary Measures. All temporary erosion and sediment control measures shall be removed within 30 days after final site stabilization or after the temporary measures are no longer needed, unless otherwise authorized by the administrator. Trapped sediment and the disturbed soil areas resulting from the disposition of temporary measures shall be permanently stabilized to prevent further erosion and sedimentation.

(19) Stormwater Management. Refer to SCC 13.10.010(11) through (13) and 13.10.030. (Ord. 2014-09; Ord. 2007-20).

13.10.050 Construction inspection provisions.

(1) The administrator, or designee, shall inspect the land-disturbing activity during construction for:

(a) Compliance with the approved erosion and sediment control plan;

(b) Compliance with the approved stormwater management plan;

(d) Development and implementation of any additional control measures necessary to address a TMDL.

(2) The administrator, or designee, may, at reasonable times and under reasonable circumstances, enter any establishment or upon any property, public or private, for the purpose of obtaining information or conducting surveys or investigations necessary in the enforcement of the provisions of this title.

(3) In accordance with a performance bond with surety, cash escrow, letter of credit, any combination thereof, or such other legal arrangement or instrument, the administrator may also enter any establishment or upon any property, public or private, for the purpose of initiating or maintaining appropriate actions which are required by the permit conditions associated with a land-disturbing activity when a permittee, after proper notice, has failed to take acceptable action within the time specified.

(4) Pursuant to Section 62.1-44.15:40 of the Code of Virginia, the administrator may require every VSMP permit or VESCP permit applicant or permittee, or any such person subject to VSMP permit or VESCP permit requirements under this title, to furnish when requested such application materials, plans, specifications, and other pertinent information as may be necessary to determine the effect of his discharge on the quality of state waters, or such other information as may be necessary to accomplish the purposes of this title.

(5) Post-construction inspections of stormwater management facilities required by the provisions of this title shall be conducted by the administrator, or designee, pursuant to the city’s adopted and State Board approved inspection program, and shall occur, at minimum, at least once every five years except as may otherwise be provided for in SCC 13.10.010(17).

(6) Stormwater management and erosion and sediment control construction inspection shall utilize the final approved plans and specifications for compliance. In addition, the inspection shall comply with the latest version of the Virginia Stormwater Management Law and Regulations, Erosion and Sediment Control Law and Regulations, promulgated pursuant to Article 2.4 (Section 62.1-44.15:58) of Chapter 3.1 of Title 62.1 of the Code of Virginia.

(a) Pre-Construction Meeting. Prior to any land-disturbing activity and upon receipt of the VSMP permit or VESCP permit from the administrator, the owner shall schedule a pre-construction meeting. The owner shall provide a minimum of 48 hours’ notice to the administrator for this meeting.

(b) Notice of Construction Commencement. The applicant must notify the administrator in advance before the commencement of construction. In addition, the applicant must notify the administrator in advance of construction of critical components of the SWM facility(ies) and erosion and sediment control measures.

(c) Periodic inspections of the stormwater management system and erosion and sediment control construction shall be conducted by the administrator or designee, a DEQ-certified inspector. Upon completion, the applicant and owner are responsible for certifying that the completed project is in accordance with the approved plans and specifications and shall provide regular inspections sufficient to adequately document compliance. The inspector shall be a DEQ-certified inspector. All inspections shall be documented and written reports prepared that contain the following information:

(i) The date and location of the inspection;

(ii) Whether construction is in compliance with the approved stormwater management plan, erosion control plan, stormwater pollution prevention plan, and pollution prevention plan;

(iii) Variations from the approved construction specifications; and

(iv) Any violations that exist.

(d) If any violations are found, the property owner shall be notified in writing of the nature of the violation and the required corrective actions. No additional work shall proceed until any violations are corrected and all work previously completed has received approval by the administrator.

(e) In addition, the person responsible for carrying out the plan may be required to provide inspection monitoring and reports to ensure compliance with the approved plan and to determine whether the measures required in the plan provide effective stormwater management.

(f) If the administrator determines that there is a failure to comply with the plan, notice shall be served upon the permittee or person responsible for carrying out the plan in accordance with Chapter 13.14 SCC.

(7) Post-Construction Final Inspection and As-Built Plans.

(a) All applicants are required to submit a construction record drawing for permanent stormwater management facilities to the administrator. The construction record drawing shall be appropriately sealed and signed by a professional registered in the Commonwealth of Virginia, certifying that the stormwater management facilities have been constructed in accordance with the approved plan.

(b) A final inspection by the administrator is required before the release of any performance securities can occur.

(c) Prior to release of any performance securities, the applicant is required to provide a certification statement from a licensed engineer that all stormwater management facilities were properly installed and/or constructed per the approved plan and per any manufacturer’s recommendations. The engineer is expected to provide the on-site observation needed to provide such certification. The certification statement shall cover all aspects of the stormwater management facility construction, including surface as-built surveys, geotechnical inspections during subsurface or backfilling, riser and principal spillway installation, bioretention soil placement and compaction activities. (Ord. 2014-09; Ord. 2007-30; Ord. 2007-20).

13.10.060 Maintenance and repair of stormwater facilities.

(1) Maintenance Inspection of Stormwater Facilities.

(a) All stormwater management facilities must undergo inspections to document maintenance and repair needs and ensure compliance with the requirements of Division I of this title and accomplishment of its purposes. These needs may include removal of silt, litter and other debris from all catch basins, inlets and drainage pipes; grass cutting and vegetation removal; and necessary replacement of landscape vegetation and any repair or replacement of structural features.

(b) In compliance with the maintenance covenant included in the approved comprehensive drainage plan, the owner, or any successor owner, unless such responsibility is lawfully transferred to the city, shall inspect, maintain and repair all structural and nonstructural stormwater management measures required by the plan.

(2) Records of Maintenance and Repair Activities. Parties responsible for the operation and maintenance of a stormwater management facility shall make records of the installation and of all maintenance and repairs, and shall retain the records for at least five years. These records shall be made available to the administrator during inspection of the facility and at other reasonable times upon request. (Ord. 2014-09; Ord. 2007-20).