(a) (1) Best management practices as set forth in subsection (b) of this Code section shall be required for all land-disturbing activities. Proper design, installation, and maintenance of best management practices shall constitute a complete defense to any action by the director or to any other allegation of noncompliance with paragraph (2) of this subsection or any substantially similar terms contained in a permit for the discharge of storm water issued pursuant to subsection (f) of Code Section 12-5-30 . As used in this subsection, the terms "proper design" and "properly designed" mean designed in accordance with the hydraulic design specifications contained in the "Manual for Erosion and Sediment Control in Georgia" specified in subsection (b) of this Code section. (2) A discharge of storm-water runoff from disturbed areas where best management practices have not been properly designed, installed, and maintained shall constitute a separate violation of any land-disturbing permit issued by a local issuing authority or of any state general permit issued by the division pursuant to subsection (f) of Code Section 12-5-30 for each day on which such discharge results in the turbidity of receiving waters being increased by more than 25 nephelometric turbidity units for waters supporting warm water fisheries or by more than ten nephelometric turbidity units for waters classified as trout waters. The turbidity of the receiving waters shall be measured in accordance with guidelines to be issued by the director. This paragraph shall not apply to any land disturbance associated with the construction of single-family homes which are not part of a larger common plan of development or sale unless the planned disturbance for such construction is equal to or greater than five acres. (3) Failure properly to design, install, or maintain best management practices shall constitute a violation of any land-disturbing permit issued by a local issuing authority or of any state general permit issued by the division pursuant to subsection (f) of Code Section 12-5-30 for each day on which such failure occurs. (4) The director may require, in accordance with regulations adopted by the board, reasonable and prudent monitoring of the turbidity level of receiving waters into which discharges from land-disturbing activities occur. (b) The rules and regulations, ordinances, or resolutions adopted pursuant to this chapter for the purpose of governing land-disturbing activities shall require, as a minimum, protections at least as stringent as the state general permit; and best management practices, including sound conservation and engineering practices to prevent and minimize erosion and resultant sedimentation, which are consistent with, and no less stringent than, those practices contained in the "Manual for Erosion and Sediment Control In Georgia" published by the State Soil and Water Conservation Commission as of January 1 of the year in which the land-disturbing activity was permitted, as well as the following: (1) Stripping of vegetation, regrading, and other development activities shall be conducted in such a manner so as to minimize erosion; (2) Cut and fill operations must be kept to a minimum; (3) Development plans must conform to topography and soil type, so as to create the lowest practicable erosion potential; (4) Whenever feasible, natural vegetation shall be retained, protected, and supplemented; (5) The disturbed area and the duration of exposure to erosive elements shall be kept to a practicable minimum; (6) Disturbed soil shall be stabilized as quickly as practicable; (7) Temporary vegetation or mulching shall be employed to protect exposed critical areas during development; (8) Permanent vegetation and structural erosion control measures must be installed as soon as practicable; (9) To the extent necessary, sediment in run-off water must be trapped by the use of debris basins, sediment basins, silt traps, or similar measures until the disturbed area is stabilized. As used in this paragraph, a disturbed area is stabilized when it is brought to a condition of continuous compliance with the requirements of this chapter; (10) Adequate provisions must be provided to minimize damage from surface water to the cut face of excavations or the sloping surfaces of fills; (11) Cuts and fills may not endanger adjoining property; (12) Fills may not encroach upon natural watercourses or constructed channels in a manner so as to adversely affect other property owners; (13) Grading equipment must cross flowing streams by the means of bridges or culverts, except when such methods are not feasible, provided, in any case, that such crossings must be kept to a minimum; (14) Land-disturbing activity plans for erosion and sedimentation control shall include provisions for treatment or control of any source of sediments and adequate sedimentation control facilities to retain sediments on site or preclude sedimentation of adjacent waters beyond the levels specified in subsection (a) of this Code section; (15) (A) There is established a 25 foot buffer along the banks of all state waters, as measured horizontally from the point where vegetation has been wrested by normal stream flow or wave action, except: (i) As provided by paragraphs (16) and (17) of this subsection; (ii) Where the director determines to allow a variance that is at least as protective of natural resources and the environment; (iii) Where otherwise allowed by the director pursuant to Code Section 12-2-8 ; (iv) Where a drainage structure or a roadway drainage structure must be constructed, provided that adequate erosion control measures are incorporated in the project plans and specifications and are implemented; (v) Along any ephemeral stream. As used in this division, the term "ephemeral stream" means a stream: (I) That under normal circumstances has water flowing only during and for a short duration after precipitation events; (II) That has the channel located above the ground-water table year round; (III) For which ground water is not a source of water; and (IV) For which runoff from precipitation is the primary source of water flow; or (vi) Where shoreline stabilization is installed; provided, however, that this exception shall be limited to the construction of bulkheads and sea walls only to the extent required to prevent the erosion of the shoreline. This exception shall be limited to Lake Oconee and Lake Sinclair and shall be limited to the duration of such construction. Unless exempted under division (v) of this subparagraph, buffers of at least 25 feet established pursuant to Part 6 of Article 5 of Chapter 5 of this title shall remain in force unless a variance is granted by the director as provided in this paragraph. (B) No land-disturbing activities shall be conducted within any such buffer; and a buffer shall remain in its natural, undisturbed state of vegetation until all land-disturbing activities on the construction site are completed, except as otherwise provided by this paragraph. Once the final stabilization of the site is achieved, a buffer may be thinned or trimmed of vegetation as long as a protective vegetative cover remains to protect water quality and aquatic habitat and a natural canopy is left in sufficient quantity to keep shade on the stream bed; provided, however, that any person constructing a single-family residence, when such residence is constructed by or under contract with the owner for his or her own occupancy, may thin or trim vegetation in a buffer at any time as long as protective vegetative cover remains to protect water quality and aquatic habitat and a natural canopy is left in sufficient quantity to keep shade on the stream bed. (C) On or before December 31, 2004, the board shall adopt rules which contain specific criteria for the grant or denial by the director of requests for variances. After such date, no variance shall be granted by the director which is not consistent with the criteria contained in such rules. Such rules shall provide, at a minimum, that the director shall consider granting a variance in the following circumstances: (i) Where a proposed land-disturbing activity within the buffer would require the landowner to acquire a permit from the United States Army Corps of Engineers under Section 404 of the federal Water Pollution Control Act Amendment of 1972, 33 U.S.C. Section 1344 , and the Corps of Engineers has approved a mitigation plan to be implemented as a condition of such a permit; (ii) Where the landowner provides a plan satisfactory to the director that shows that, even with the proposed land-disturbing activity within the buffer, the completed project will result in maintained or improved water quality downstream of the project; or (iii) Where a project with a proposed land-disturbing activity within the buffer is located in or upstream and within ten linear miles of a stream segment listed as impaired under Section 303(d) of the federal Water Pollution Control Act Amendment of 1972, 33 U.S.C. Section 1313(d) and the landowner provides a plan satisfactory to the director that shows that the completed project will result in maintained or improved water quality in such listed stream segment and that the project has no adverse impact relative to the pollutants of concern in such stream segment. All projects covered under divisions (i), (ii), and (iii) of this subparagraph shall meet all criteria set forth in rules for specific variance criteria adopted by the board by December 31, 2004. (D) The buffer shall not apply to the following land-disturbing activities, provided that they occur at an angle, as measured from the point of crossing, within 25 degrees of perpendicular to the stream; cause a width of disturbance of not more than 50 feet within the buffer; and adequate erosion control measures are incorporated into the project plans and specifications and are implemented: (i) Stream crossings for water lines; or (ii) Stream crossings for sewer lines; (16) There is established a 50 foot buffer, as measured horizontally from the point where vegetation has been wrested by normal stream flow or wave action, along the banks of any state waters classified as "trout streams" pursuant to Article 2 of Chapter 5 of this title except where a roadway drainage structure must be constructed; provided, however, that small springs and streams classified as trout streams which discharge an average annual flow of 25 gallons per minute or less shall have a 25 foot buffer or they may be piped, at the discretion of the landowner, pursuant to the terms of a rule providing for a general variance promulgated by the board providing for notice to the division or local issuing authority of the location and extent of the piping and prescribed methodology for minimizing the impact of such piping and for measuring the volume of water discharged by the stream. Any such pipe must stop short of the downstream landowner's property, and the landowner must comply with the buffer requirement for any adjacent trout streams. The director may grant a variance from such buffer to allow land-disturbing activity, provided that adequate erosion control measures are incorporated in the project plans and specifications and are implemented. The following requirements shall apply to any such buffer: (A) No land-disturbing activities shall be conducted within a buffer and a buffer shall remain in its natural, undisturbed state of vegetation until all land-disturbing activities on the construction site are completed. Once the final stabilization of the site is achieved, a buffer may be thinned or trimmed of vegetation as long as a protective vegetative cover remains to protect water quality and aquatic habitat and a natural canopy is left in sufficient quantity to keep shade on the stream bed; provided, however, that any person constructing a single-family residence, when such residence is constructed by or under contract with the owner for his or her own occupancy, may thin or trim vegetation in a buffer at any time as long as protective vegetative cover remains to protect water quality and aquatic habitat and a natural canopy is left in sufficient quantity to keep shade on the stream bed; (B) On or before December 31, 2000, the board shall adopt rules which contain specific criteria for the grant or denial by the director of requests for variances. After such date, no variance shall be granted by the director which is not consistent with the criteria contained in such rules; provided, however, that, should the board fail to adopt rules which contain specific criteria for the grant or denial of requests for variances by the director on or before December 31, 2000, the authority of the director to issue such variances shall be suspended until the board adopts such rules; and (C) The buffer shall not apply to the following land-disturbing activities, provided that they occur at an angle, as measured from the point of crossing, within 25 degrees of perpendicular to the stream; they cause a width of disturbance of not more than 50 feet within the buffer; and adequate erosion control measures are incorporated into the project plans and specifications and are implemented: (i) Stream crossings for water lines; or (ii) Stream crossings for sewer lines; and (17) (A) There is established a 25 foot buffer along coastal marshlands, as measured horizontally from the coastal marshland-upland interface, as determined in accordance with Part 4 of Article 4 of Chapter 5 of this title, the "Coastal Marshlands Protection Act of 1970," and the rules and regulations promulgated thereunder, except: (i) Where the director determines to allow a variance that is at least as protective of natural resources and the environment; (ii) Where otherwise allowed by the director pursuant to Code Section 12-2-8 ; (iii) Where an alteration within the buffer area has been authorized pursuant to Code Section 12-5-286 ; (iv) For maintenance of any currently serviceable structure, landscaping, or hardscaping, including bridges, roads, parking lots, golf courses, golf cart paths, retaining walls, bulkheads, and patios; provided, however, that if such maintenance requires any land-disturbing activity, adequate erosion control measures are incorporated into the project plans and specifications and such measures are fully implemented; (v) Where a drainage structure or roadway drainage structure is constructed or maintained; provided, however, that adequate erosion control measures are incorporated into the project plans and specifications and such measures are fully implemented; (vi) On the landward side of any currently serviceable shoreline stabilization structure; and (vii) For the maintenance of any manmade storm-water detention basin, golf course pond, or impoundment that is located entirely within the property of a single individual, partnership, or corporation; provided, however, that adequate erosion control measures are incorporated into the project plans and specifications and such measures are fully implemented. (B) No land-disturbing activity shall be conducted within any such buffer and a buffer shall remain in its current, undisturbed state of vegetation until all land-disturbing activities on the construction site are completed, except as otherwise provided by this paragraph. Once the final stabilization of the site is achieved, a buffer may be thinned or trimmed of vegetation so long as a protective vegetative cover remains to protect water quality and aquatic habitat; provided, however, that any person constructing a single-family residence, when such residence is constructed by or under contract with the owner for his or her own occupancy, may thin or trim vegetation in a buffer at any time so long as a protective vegetative cover remains to protect water quality and aquatic habitat. (C) On or before December 31, 2015, the board shall promulgate rules and regulations that: (i) Contain criteria for the grant or denial by the director of requests for variances pursuant to this paragraph, including where an alteration within the buffer area has been authorized pursuant to a permit issued by the United States Army Corps of Engineers under Section 404 of the Federal Water Pollution Control Act of 1972, as amended, or Section 10 of the Rivers and Harbors Act of 1899; provided, however, that adequate erosion control measures are incorporated into the project plans and specifications and such measures are fully implemented; and (ii) Provide for variances by rule, subject to specified conditions, for certain categories of activities within the buffer that will have minimal impact on the water quality or aquatic habitat of the adjacent marsh, including where the area within the buffer is not more than 500 square feet; provided, however, that adequate erosion control measures are incorporated into the project plans and specifications and such measures are fully implemented. (D) The board may adopt rules and regulations that provide for an expedited process for certain categories of activities within the buffer based on the size, scope, location, and character of the proposed activity within the buffer. (E) The buffer requirements of this paragraph shall not apply to crossings for utility lines that cause a width of disturbance of not more than 50 feet within the buffer; provided, however, that adequate erosion control measures are incorporated into the project plans and specifications and such measures are fully implemented. (F) The buffer shall not apply to: (i) Any land-disturbing activity conducted pursuant to and in compliance with a valid and effective land-disturbing permit issued subsequent to April 22, 2014, and prior to December 31, 2015; provided, however, that adequate erosion control measures are incorporated into the project plans and specifications and such measures are fully implemented; or (ii) Any lot for which the preliminary plat has been approved prior to December 31, 2015, if roadways, bridges, or water and sewer lines have been extended to such lot prior to December 31, 2015, and if the requirement to maintain a 25 foot buffer would consume at least 18 percent of the high ground of the platted lot otherwise available for development; provided, however, that adequate erosion control measures are incorporated into the project plans and specifications and such measures are fully implemented. (b.1) On or before June 30, 2022, the board shall promulgate rules and regulations that contain specific criteria for the approval or denial by the director of requests for variances for road construction and maintenance projects undertaken by the Department of Transportation when: (1) An alteration within the buffer area has been authorized pursuant to a permit issued by the United States Army Corps of Engineers under Section 404 of the Federal Water Pollution Control Act of 1972, as amended, or Section 10 of the Rivers and Harbors Act of 1899; provided, however, that adequate erosion control measures are incorporated into the project plans and specifications and such measures are fully implemented; or (2) The land-disturbing activity is not eligible for a permit issued by the United States Army Corps of Engineers under Section 404 of the Federal Water Pollution Control Act of 1972, as amended, and involves the piping, filling, or rerouting of waters that are not jurisdictional waters of the United States regardless as to whether or not such waters have been classified as primary or secondary trout waters. (c) Nothing contained in this chapter shall prevent any local issuing authority from adopting rules and regulations, ordinances, or resolutions which contain stream buffer requirements that exceed the minimum requirements in subsection (b) of this Code section. (d) The fact that land-disturbing activity for which a permit has been issued results in injury to the property of another shall neither constitute proof of nor create a presumption of a violation of the standards provided for in this Code section or the terms of the permit.