(a) To minimize the adverse effects of human activities on the other components of the RPA, state waters, and aquatic life, a 100-foot wide buffer area of vegetation as described in the Buffer Guidelines shall be provided. The purpose of the buffer is to retard runoff, prevent erosion, and filter nonpoint source pollution from runoff and it shall be retained if present and established where it does not exist in accordance with the Buffer Guidelines.

(b) For purposes of calculating the impact of the proposed development on water quality, the required 100-foot wide RPA buffer area shall be deemed to achieve a 75 percent reduction of sediments and a 40 percent reduction of nutrients.

(c) Where land uses such as agriculture or silviculture within the area of the buffer cease and the lands are proposed to be converted to other uses, the full 100-foot wide buffer shall be reestablished. In reestablishing the buffer, management measures shall be undertaken to provide woody vegetation that assures the buffer functions set forth in this chapter. Reestablishment must be accomplished in accordance with the Buffer Guidelines, as may be amended from time to time.

(d) Permitted modifications of the buffer area:

Existing woody vegetation may be removed to provide for reasonable sight lines, access paths, and shoreline erosion control best management practices, if authorized by the CBPA Manager, on a case-by-case basis, upon submittal of a WQIA documenting that the RPA buffer functions will be maintained and vegetation will be replaced.

     (1) Trees may be thinned and pruned for sight lines, provided that where removed, they shall be replaced with other vegetation that is equally effective in retarding runoff, preventing erosion, and filtering nonpoint source pollution from runoff in accordance with the Buffer Guidelines.

     (2) Any access path shall be constructed and surfaced so as to effectively control erosion and aligned to minimize tree removal and environmental impact.

    (3) For approved shoreline erosion control best management practices, trees and woody vegetation may be removed, necessary control techniques employed, and appropriate vegetation established to protect or stabilize the shoreline in accordance with the best available technical advice, applicable permit conditions or requirements and in accordance with the Buffer Guidelines.

     (4) Dead or diseased trees or shrubbery may be removed pursuant to sound horticultural practice in accordance with the Buffer Guidelines.

     (5) The following modifications to the buffer do not require a WQIA or plan approval if performed as described in the Buffer Guidelines:

          a. Home landscaping such as pruning, mowing, mulching; and

         b. Removal of noxious weeds provided they are replaced with vegetation equally suited for the growing environment and no land disturbance takes place.

(e) On land used for agricultural purposes, the agricultural buffer area shall be managed to prevent concentrated flows of surface water from breaching the buffer area and noxious weeds from invading the buffer area. Agricultural activities may encroach into the buffer area provided that the provisions of Virginia’s Chesapeake Bay Preservation Area Designation and Management Regulations (Section 9 VAC 10-20-130.5b 1-5 and 10-20-120.9) as they may be amended from time to time, are met.

(f) Permitted encroachments into the buffer area:

     (1) When the application of the RPA buffer would result in the loss of an adequate, as determined by the CBPA Manager, buildable area on a lot or parcel legally created prior to October 1, 1989, the CBPA Manager may permit an encroachment into the buffer area in accordance with following criteria:

         a. Encroachments into the buffer area shall be the minimum necessary to achieve a reasonable buildable area for a principal structure and necessary utilities. Detached accessory structures shall not be eligible for encroachment authorizations.

          b. Where practicable, a vegetated area that will maximize water quality protection, mitigate the effects of the buffer encroachment, and is equal to the area of encroachment into the buffer area shall be established elsewhere on the lot.

          c. The encroachment may not extend into the seaward 50 feet of the buffer area.

          d. Encroachments into the buffer processed through an administrative review shall be subject to the findings required by subsection 23.2-13 but without the requirement for a public hearing, such findings to be made instead by the CBPA Manager.

     (2) When the application of the buffer area would result in the loss of a buildable area on a lot or parcel recorded between October 1, 1989 and March 1, 2002, or on a lot or parcel legally created prior to January 1, 2004, and effected by a perennial steam determination, encroachments into the buffer area may be allowed through an administrative process in accordance with the following criteria:

          a. The lot or parcel was created as a result of a legal process conducted in conformity with the County's subdivision regulations;

          b. Conditions or mitigation measures imposed through a previously approved exception shall be met;

          c. If the use of a BMP was previously required, the BMP shall be evaluated to determine if it continues to function effectively and if necessary the BMP shall be reestablished or repaired and maintained as required; and

          d. The criteria of subdivision (f)(1) of this section shall be met.

(g) Redevelopment within IDA's may be exempt from the RPA buffer requirement in accordance with the development review process, provided that the water quality standards found in section 23.2-7 Performance Standards, can be achieved.

(h) Nothing contained herein shall be construed to prevent an RPA buffer area from being used to fulfill minimum open space standards required in chapter 24.1, Zoning, County Code.

(Ord. No. 05-13(R), 5/17/05)