In this chapter, the following terms have the meanings indicated. Terms Defined. “Accessory” means a structure that is: Detached from a principal structure; Located on the same lot as the principal structure; and Customarily incidental and subordinate to the principal structure. “Addition” means a newly constructed area that increases the size of a structure. Buffer Management Plan. “Buffer management plan” means a narrative, graphic description, or plan of the buffer that is necessary when an applicant proposes a development activity that will: Affect a portion of the buffer; Alter buffer vegetation; or Require the establishment of a portion of the buffer in vegetation. “Buffer management plan” includes a major buffer management plan, a minor buffer management plan, and a simplified buffer management plan. “Caliper” has the meaning stated in COMAR 08.19.03.01. “Canopy tree” means a tree that, when mature, reaches a height of at least 35 feet. “Ecosystem” means a more or less self-contained biological community together with the physical environment in which the community’s organisms occur. “Fully established” means the buffer contains as much diverse, native vegetation as necessary to support a firm and stable riparian habitat capable of self-sustaining growth and regeneration. Hazardous Tree. “Hazardous tree” means: A tree with a structural defect, such as a crack, canker, weak branch union, decay, dead wood, root damage, or root disease, that decreases the structural integrity of the tree and which, because of its location, is likely to fall and cause personal injury or property damage, including acceleration of soil erosion; or Based on its location in the landscape, a healthy tree that, with continued normal growth, will damage an existing permanent structure or significantly increase the likelihood of soil erosion. “Hazardous tree” does not include a tree for which the likelihood of personal injury, property damage, or soil erosion can reasonably be eliminated or significantly diminished: With routine and proper arboricultural practices, such as regular watering, application of fertilizer or mulch, and pruning; or By relocation of property that is likely to be damaged. “In-kind replacement” means the removal of a structure and the construction of another structure that is smaller than or identical to the original structure in use, footprint area, width, and length. “Invasive species” means a type of plant that is non-native to the ecosystem under consideration and whose introduction causes, or is likely to cause, economic or environmental harm or harm to human health. Repealed. “Large shrub” means a shrub that, when mature, reaches a height of at least 6 feet. “Limit of disturbance” means the area of a development or redevelopment activity that includes temporary disturbance and permanent disturbance. “Major buffer management plan” means a plan and supporting documentation required under Regulation .01-3J of this chapter. “Minor buffer management plan” means a plan and supporting documentation required under Regulation .01-3I of this chapter. “Native” means indigenous to the physiographic area in Maryland where the planting is proposed. “Natural regeneration” has the meaning stated in COMAR 08.19.03.01. Permanent Disturbance. “Permanent disturbance” means a material, enduring change in the topography, landscape, or structure that occurs as part of a development or redevelopment activity. “Permanent disturbance” includes: Construction or installation of any material that will result in lot coverage; Construction of a deck; Except under §B(18-2)(b)(iii) of this regulation, grading; Except under §B(18-2)(b)(ii) of this regulation, clearing of a tree, forest, or developed woodland; and A septic system in a forest or developed woodland on a lot created before local program approval, if clearing is required. “Permanent disturbance” does not include a septic system on a lot created before local program approval if the septic system is located in existing grass or clearing is not required. “Simplified buffer management plan” means a plan required for an application under Regulation .01-3H of this chapter. “Small shrub” means a shrub that, when mature, reaches a height of up to 6 feet. Repealed. “Substantial alteration” means a repair, reconstruction, replacement, or improvement of a principal structure, with a proposed total footprint that is at least 50 percent greater than that of the structure that is the subject of the application. “Supplemental planting plan” means a description and landscape schedule that shows the proposed species type, quantity, and size of plants to be located within a buffer if natural regeneration does not meet the required stem density. Temporary Disturbance. “Temporary disturbance” means a short-term change in the landscape that occurs as part of a development or redevelopment activity. “Temporary disturbance” includes: Storage of materials that are necessary for the completion of the development or redevelopment activity; Construction of a road or other pathway that is necessary for access to the site of the development or redevelopment activity, if the road or pathway is removed immediately after completion of the development or redevelopment activity and the area is restored to its previous vegetative condition; Grading of a development site, if the area is restored to its previous vegetative condition immediately after completion of the development or redevelopment activity; and Locating a septic system on a lot created before local program approval if the septic system is located in existing grass or clearing is not required. “Temporary disturbance” does not include: A septic system in a forest or developed woodland on a lot created before local program approval, if clearing is required; and A violation. “Understory tree” means a tree that, when mature, reaches a height of 12 to 35 feet. Repealed. Policies. In developing and updating its Critical Area program, a local jurisdiction shall use all of the following policies with regard to the buffer: Provide for the removal or reduction of sediments, nutrients, and potentially harmful or toxic substances in runoff entering the Chesapeake and Atlantic Coastal Bays or their tributaries; Minimize the adverse effects of human activities on wetlands, shorelines, stream banks, tidal waters, and aquatic resources; Maintain an area of transitional habitat between aquatic and upland communities; Maintain the natural environment of streams; and Protect riparian wildlife habitat. Authority of Secretary; Scope; Alternative Procedures and Requirements. The provisions of this chapter may not be construed to limit the authority of the Secretary of Agriculture under Agriculture Article, Title 9, Subtitle 4, Annotated Code of Maryland. Except for a shoreline stabilization measure in a modified buffer area, the provisions of this regulation through Regulation .01-7 of this chapter do not apply within a modified buffer area under Regulation .01-8 of this chapter. A local jurisdiction may adopt alternative procedures and requirements for the provisions of this chapter if: The alternative procedures and requirements are at least as effective as the Critical Area program under Natural Resources Article, Title 8, Subtitle 18, Annotated Code of Maryland, regulations adopted under the authority of that subtitle, and any additional requirements of the local program; and The Commission has approved those alternative procedures and requirements. Buffer Standards. In conjunction with mitigation performed in accordance with an approved buffer management plan under Regulation .01-3 of this chapter, a local jurisdiction may authorize disturbance in the buffer for: A development activity: Associated with a water-dependent facility or activity under COMAR 27.01.03; Authorized under a variance; In accordance with §E(8) of this regulation; In accordance with Regulation .01-3B of this chapter; or Associated with the placement of dredged material under COMAR 27.01.03.03D; or In accordance with COMAR 26.24.02, a shoreline stabilization measure under COMAR 27.01.04. Except as authorized under §E(1) of this regulation, a local jurisdiction may not authorize disturbance in the buffer. Except for the buffer widths under §E(5)—(7) of this regulation and based on existing field conditions, a local jurisdiction shall require the measurement of a buffer of at least 100 feet [landward from]: Landward from the mean high water line of tidal waters; From the landward boundary of a tidal wetland; and From the edge of each bank of a tributary stream. To calculate the buffer widths under §E(5)—(7) of this regulation, a local jurisdiction shall require the measurement of the buffer from the points specified under §E(3) of this regulation. If a local jurisdiction grants final local approval for a subdivision or a site plan in a resource conservation area on or after July 1, 2008, the local jurisdiction shall require: A buffer of at least 200 feet landward from the mean high water line of tidal waters or from the landward boundary of a tidal wetland; and An expanded buffer in accordance with §E(7) of this regulation. The provisions of §E(5)(a) of this regulation do not apply if: The application for subdivision or site plan approval was submitted before July 1, 2008, and legally recorded by July 1, 2010; The application involves the use of growth allocation; or A local program procedure approved by the Commission provides for the reduction of the strict application of a 200-foot buffer under §E(5)(a) of this regulation if a 200-foot buffer would preclude a subdivision of the property at a density of one dwelling unit per 20 acres or an intra-family transfer authorized under Natural Resources Article, §8-1808.2, Annotated Code of Maryland. If a buffer is contiguous to a steep slope, a nontidal wetland, a nontidal wetland of special State concern under COMAR 26.23.06, a hydric soil, or a highly erodible soil, a local jurisdiction shall expand the buffer width required under §E(3) or (5)(a) of this regulation and shall calculate the extent of that expansion in accordance with all of the following requirements: A steep slope at a rate of 4 feet for every 1 percent of slope or to the top of the slope, whichever is greater; In accordance with COMAR 26.23.01.01B; A nontidal wetland to its upland boundary; and A nontidal wetland of special State concern to include the wetland and its regulated 100-foot buffer; and A highly erodible soil on a slope less than 15 percent or a hydric soil, to the lesser of: The landward boundary; or 300 feet, including the buffer width required under §E(3) or (5)(a) of this regulation. If a buffer is contiguous to a hydric soil or to a highly erodible soil on a slope less than 15 percent and that buffer is located on a lot or parcel that was created before January 1, 2010, a local jurisdiction may authorize a development activity in the expanded buffer if: The location of the development activity is in the expanded portion of the buffer but not in the buffer required under §E(3) of this regulation; The buffer occupies at least 75 percent of the lot or parcel; and Mitigation occurs at a 2:1 ratio based on the lot coverage of the proposed development activity that is in the expanded buffer.