(A) Statement of purpose.
(1) Regulating certain land-disturbing activities to control accelerated erosion and sedimentation in order that water pollution from sedimentation may be controlled, and that the accelerated erosion and sedimentation of lakes and natural watercourses and damage to public and private property by sedimentation be inhibited; and
(2) Establishing procedures through which these purposes can be fulfilled.
(B) Scope and exclusions of section. This section shall apply to land-disturbing activities undertaken by any person, with the following exclusions.
(1) Those undertaken on agricultural land for the production of plants and animals useful to humans, including, but not limited to: forage and sod crops, grain and feed crops, tobacco, cotton and peanuts; dairy animals and dairy products; poultry and poultry products; livestock, including beef cattle, sheep, swine, horses, ponies, mules or goats, including the breeding and grading of any or all those animals; bees and apiary products; and fur animals;
(2) Those undertaken on forest land for the production and harvesting of timber and timber products;
(3) Activities undertaken by persons as defined in G.S. § 113A-52(7) who are otherwise regulated by the provisions of the Mining Act of 1971, G.S. §§ 74-46 through 74-68; and
(4) Those land-disturbing activities over which the state, by statute, has exclusive regulatory jurisdiction, which are activities:
(a) Conducted by the state;
(b) Conducted by the United States;
(c) Conducted by persons having the power of eminent domain;
(d) Conducted by local governments;
(e) Licensed by the state or the United States; and
(f) Funded in whole or in part by the state or the United States.
(C) General requirements. Persons engaged in land-disturbing activities shall take all reasonable measures to protect all public and private property from damage by those activities.
(D) Basic control objectives. The basic control objectives which are to be considered in developing and implementing an erosion and sedimentation control plan are to:
(1) Identify critical areas. On-site areas which are subject to severe erosion, and off-site areas which are especially vulnerable to damage from erosion or sedimentation, are to be identified and receive special attention;
(2) Limit time of exposure. All land-disturbing activities are to be planned and conducted to limit exposure to the shortest feasible time;
(3) Limit exposed areas. All land-disturbing activities are to be planned and conducted to minimize the size of the area to be exposed at any one time;
(4) Control surface water. Surface water runoff originating upgrade of exposed areas shall be controlled to reduce erosion and sediment loss during the period of exposure;
(5) Control sedimentation. All land-disturbing activities are to be planned and conducted so as to prevent off-site sedimentation damage; and
(6) Manage stormwater runoff. When the increase in the velocity of storm water runoff resulting from a land-disturbing activity is sufficient to cause accelerated erosion of the receiving watercourse, plans are to include measures to control the velocity at the point of discharge so as to minimize accelerated erosion of the site and increased sedimentation of the stream.
(E) Standards for land-disturbing activity.
(1) Specifically. Land-disturbing activities subject to the control of this section shall be undertaken except in accordance with the following standards.
(a) Buffer zone. Land-disturbing activity shall not be permitted in proximity to a lake or natural watercourse unless a buffer zone is provided along the margin of the watercourse of sufficient width to confine visible siltation within the 25% of the buffer zone nearer the land-disturbing activity; provided, that this division (E) shall not apply to a land-disturbing activity in connection with the construction of facilities to be located on, over or under a lake or natural watercourse.
(b) Graded slopes and fills. The angle for graded slopes and fills shall be no greater than the angle which can be retained by vegetative cover or other adequate erosion control devices or structures. In any event, slopes left exposed will, within 30 working days of completion of any phase of grading, be planted or otherwise provided with ground cover, devices or structures sufficient to restrain erosion.
(c) Ground cover. Whenever land-disturbing activity is undertaken on a tract comprising more than one acre, if more than one contiguous acre is uncovered, the person conducting the land-disturbing activity shall install the sedimentation and erosion-control devices and practices as are sufficient to retain the sediment generated by the land-disturbing activity within the boundaries of the tract during construction upon and development of the tract, and shall plant or otherwise provide a permanent ground cover sufficient to restrain erosion after completion of construction or development within 30 working days or 120 calendar days following completion, whichever period is shorter.
(d) Design and performance standard. Erosion and sedimentation control measures, structures and devices shall be so planned, designed and constructed as to provide control from the calculated peak rates of runoff from a ten-year storm. Runoff rates shall be calculated using the procedures in the USDA, Soil Conservation Services’ National Engineering Field Manual for Conservation Practices, or other acceptable calculation procedures.
(F) Permanent downstream protection of stream banks and channels.
(1) Generally. Provision shall be made for the permanent protection of off-site stream banks and channels from the erosive effects of increased velocity and volume of stormwater runoff resulting from certain land-disturbing activities.
(2) Intent. Stream banks and channels downstream from any land-disturbing activity shall be protected from increased degradation by accelerated erosion caused by increased velocity of runoff from the land-disturbing activity. The provisions of this rule will be publicly and periodically reviewed by the Board of Commissioners.
(3) Performance standard.
(a) The land-disturbing activity shall be planned and conducted so that the velocity of stormwater runoff in the receiving watercourse at the point of discharge resulting from a ten-year storm after development shall not exceed the greater of:
1. The velocity as determined from the table in division (F)(6) below; or
2. The velocity in the receiving watercourse determined for the ten-year storm prior to development.
(b) If divisions (F)(3)(a)1. or (3)(a)2. above cannot be met, the channel below the discharge point shall be designed and constructed to withstand the expected velocity.
(4) Acceptable management measures. Measures applied alone or in combination to satisfy the intent of this section are acceptable if there are no objectionable secondary consequences. The Commission recognizes that the management of stormwater runoff to minimize or control downstream channel and bank erosion is a developing technology. Innovative techniques and ideas will be considered and may be used when shown to have the potential to produce successful results. Some alternatives are to:
(a) Avoid increases in surface runoff volume and velocity by including measures to promote infiltration to compensate for increased runoff from areas rendered impervious;
(b) Avoid increases in stormwater discharge velocities by using vegetated or roughened swales and waterways in lieu of closed drains and high velocity paved sections;
(c) Provide energy dissipaters at outlets of storm drainage facilities to reduce flow velocities at the point of discharge. These may range from single rip-rapped sections to complex structures; and/or
(d) Protect watercourses subject to accelerated erosion by improving cross-sections or providing erosion-resistant lining.
(5) Exceptions. This rule shall not apply where it can be demonstrated that stormwater discharge velocities will not create an erosion problem in the receiving watercourse.
(6) Maximum permissible velocity. The following Table 156-1 provides the maximum permissible velocities for stormwater discharges:
Material | Maximum Permissible Velocities For: | |
Feet per Second | Miles per Second | |
Alluvial silts (colloidal) | 5.0 | 1.5 |
Alluvial silts (noncolloidal) | 3.5 | 1.1 |
Coarse gravel (noncolloidal) | 6.0 | 1.8 |
Cobbles and shingles | 5.5 | 1.7 |
Fine gravel | 5.0 | 1.5 |
Fine sand (noncolloidal) | 2.5 | 0.8 |
Graded, loam to cobbles (noncolloidal) | 5.0 | 1.5 |
Graded, silt to cobbles (colloidal) | 5.5 | 1.7 |
Ordinary firm loam | 3.5 | 1.1 |
Sandy loam (noncolloidal) | 2.5 | 0.8 |
Shales and hard pans | 6.0 | 1.8 |
Silt loam (noncolloidal) | 3.0 | 0.9 |
Stiff clay (very colloidal) | 5.0 | 1.5 |
Source: | ||
Adapted from recommendations by Special Committee on Irrigation Research, American Society of Civil Engineers, 1926, for channels with straight alignment. For sinuous channels, multiply allowable velocity by 0.95 for slightly sinuous channels, by 0.9 for moderately sinuous channels, and by 0.8 for highly sinuous channels. | ||
(G) Borrow and waste areas. When the person conducting the land-disturbing activity is also the person conducting the borrow or waste disposal activity, areas from which borrow is obtained and which are not regulated by the provisions of the Mining Act of 1971, and waste areas for surplus materials other than landfills regulated by the Department of Human Resources, Division of Health Services, shall be considered as part of the land-disturbing activity where the borrow material is being used or from which the waste material originated. When the person conducting the land-disturbing activity is not the person obtaining the borrow or disposing of the waste, these areas shall be considered a separate land-disturbing activity.
(H) Access and haul roads. Temporary access and haul roads, other than public roads, constructed or used in connection with any land-disturbing activity shall be considered a part of the activity.
(I) Operations in lakes or natural watercourses. Land-disturbing activity in connection with construction in, on, over or under a lake or natural watercourse shall be planned and conducted in a manner so as to minimize the extent and duration of disturbance of the stream channel. The relocation of a stream, where relocation is an essential part of the proposed activity, shall be planned and executed so as to minimize changes in the stream flow characteristics, except when justification for significant alteration to flow characteristic is provided.
(J) Responsibility for maintenance. The person engaged in or conducting the land-disturbing activity shall be responsible for maintaining all temporary and permanent erosion and sedimentation measures and facilities during the development of a site. The responsibility for maintaining all permanent erosion and sedimentation control measures and facilities after site development is completed shall lie with the landowner except facilities and measures installed within road or street right-of-way or easements accepted for maintenance by a governmental agency.
(K) Additional measures. Whenever the city determines that erosion or sedimentation is occurring as a result of a land-disturbing activity, despite application and maintenance of protective practices, the person responsible for maintenance pursuant to division (J) above will be required to take additional protective action.
(L) Permits.
(1) A person shall not undertake any land-disturbing activity subject to this section without first obtaining a permit from the Office of Planning and Inspections, except that no permit shall be required for the following land-disturbing activities:
(a) Those done for the purpose of fighting fires;
(b) The stockpiling of raw or processed sand, stone or gravel in material processing plants and storage yards; provided that sediment control measures have been utilized to protect against off-site damages; and/or
(c) Land-disturbing activities on a tract of less than 10,000 square feet. In determining the area, contiguous lands under one or diverse ownership being developed as a unit will be aggregated.
(2) A fee shall be charged for each permit issued hereunder, as specified in the City Permit Fee Schedule.
(M) Erosion and sedimentation control plans.
(1) An erosion control plan shall be prepared for all land-disturbing activities subject to this section or the subdivision regulations wherever the proposed activity is to be undertaken on a tract comprising more than one acre, if more than one contiguous acre is to be uncovered. The plan shall be filed with the City Office of Planning and Inspections, and the County Soil and Water Conservation District when required, 30 days prior to the commencement of the proposed activity or as required by the subdivision regulations.
(2) The County Soil and Water Conservation District within 20 days of receipt of any plan, or within the additional time as may be prescribed by the city, shall review the plan and submit its comments and recommendations to the City Office of Planning and Inspections. Failure of the district to submit its comments and recommendations to the city within the prescribed time will not delay final action on the plan.
(3) The Office of Planning and Inspections or the Planning Board of the city, as appropriate, will review each plan submitted and within 30 days of receipt thereof, or as required by the subdivision regulations, will notify the person submitting the plan that it has been approved, approved with modifications, approved with performance reservations or disapproved.
(4) The plan required by this section shall contain architectural and engineering drawings, maps, assumptions, calculations and narrative statements as needed to adequately describe the proposed development of the tract and the measures planned to comply with the requirements of this section. Plan content may vary to meet the needs of specific site requirements. Detailed guidelines for plan preparation may be obtained from the City Office of Planning and Inspections, on request.
(5) Application for amendment of an erosion control plan in written or graphic form may be made at any time under the same conditions as the original application. Until the time as the amendment is approved by the Office of Planning and Inspections or the Planning Board of the city, the land-disturbing activities shall not proceed except in accordance with the erosion control plan as originally approved.
(6) Plans and procedures as required by the subdivision regulations of the city shall be followed wherein they differ from this section.
(N) Appeals. Appeals to this section are specified in Chapter 159.
(O) Compliance with plan requirements; violations and penalties. Any person engaged in land-disturbing a activity who fails to file a plan in accordance with this section, or who conducts a land-disturbing activity except in accordance with provisions of an approved plan or the terms of a permit issued pursuant to division (L) above shall be deemed in violation of this section. Chapter 162 specifies penalties and enforcement for non-compliance with this section.
(P) Inspections and investigations.
(1) The Director of Planning and Inspections or designee and other appropriate officials of the city will periodically inspect the sites of land-disturbing activities to determine whether the activities are effective in controlling erosion and sediment resulting from land-disturbing activities.
(2) If, through inspection, it is determined that a person engaged in land-disturbing activities has failed to comply, a notice to comply shall be served upon that person by registered mail. The notice shall set forth the measures necessary to achieve compliance with this section, and shall state the time within which the measures must be completed. If the person engaged in the land-disturbing activities fails to comply within the time specified, he or she shall be deemed in violation of this section.
(3) The city shall have the power to conduct the investigations as it may reasonably deem necessary to carry out its duties as prescribed in this section, and for this purpose to enter at reasonable times upon any property, public or private, for the purpose of investigation and inspecting the sites of land-disturbing activities. A person shall not refuse entry or access to any authorized representative or agent of the city who requests entry for purposes of inspection, and who presents appropriate credentials, nor shall any person obstruct, hamper or interfere with any such representative while in the process of carrying out his or her official duties.
(4) The city shall also have the power to require written statements, or the filing of reports under oath, with respect to pertinent questions relating to land-disturbing activities.
(Ord. passed 7-25-2011)