A. 
The performance criteria set forth in §§ 115-22.10 through 115-22.17 of this article are intended to establish the means to minimize erosion and sedimentation potential, reduce land application of nutrients and toxics, and maximize rainwater infiltration. Natural ground cover, especially woody vegetation, is most effective in holding soil in place and preventing site erosion. Indigenous vegetation, with its adaptability to local conditions without the use of harmful fertilizers or pesticides, filters stormwater runoff. Minimizing impervious cover enhances rainwater infiltration and effectively reduces stormwater runoff potential.
B. 
The purposes of the performance criteria are to implement the following objectives: prevent a net increase in non-point source pollution from new development; achieve a ten-percent reduction in non-point source pollution from redevelopment; and achieve a forty-percent reduction in non-point source pollution from agricultural activities.
Any use, development or redevelopment of land within the Overlay District shall meet the following performance criteria.
A. 
No more land shall be disturbed than is necessary to provide for the proposed use or development.
(1) 
In accordance with an approved site plan, the limits of land disturbance, including clearing and grading, shall be strictly defined by the construction foot-print. These limits shall be clearly shown on the submitted site plan and shall be physically marked on the development site. The administrator shall review and approve the construction footprint through the plan of development process. The construction footprint shall not exceed the limits for such as designated by the zoning district of the lot or parcel.
(2) 
Ingress and egress during construction shall be limited to one access point, unless otherwise authorized by the Administrator in conjunction with the approved site plan.
B. 
Indigenous vegetation shall be preserved to the maximum extent practicable consistent with the use or development proposed.
(1) 
Existing trees over six inches diameter at breast height (DBH) shall be preserved outside the construction footprint. Diseased trees or trees weakened by age, storm, fire or other injury may be removed.
(2) 
Clearing shall be permitted only to provide necessary access, positive drainage, water quality, best management practices and the installation of utilities, as approved by the Administrator.
(3) 
Prior to clearing or grading, suitable protective barriers, such as safety fencing, shall be erected at or outside the drip line of any tree or stand of trees to be preserved. These protective barriers shall remain in place throughout all phases of construction. The storage of equipment, materials, debris or fill shall not be allowed within the area protected by such barriers.
C. 
Where the best management practices utilized require regular or periodic maintenance in order to continue their functions, such maintenance shall be ensured through a maintenance agreement with the owner or developer, or some other mechanism approved by the County Attorney that achieves an equivalent objective.
D. 
All development exceeding 2,500 square feet of land disturbance shall be subject to the plan of development review process as set forth in Division IV of this article.
E. 
Land development shall minimize impervious cover consistent with the proposed use or development in order to promote infiltration of stormwater into the ground.
(1) 
Parking areas and driveways shall be designed and improved so as to minimize impervious cover and, wherever possible based on the nature and volume of vehicular traffic, grid and modular paving blocks which promote infiltration of stormwater shall be used in parking areas and driveways.
(2) 
In order to minimize impervious cover, the dimensions of parking spaces and width of driveways and access aisles shall be no greater than necessary to comply with the requirements of this chapter and to provide for safe and convenient vehicular movement.
F. 
Any land-disturbing activity that exceeds an area of 2,500 square feet (including, but not limited to, construction of all single-family dwellings, septic tanks and drainfields) shall comply with the requirements of the Erosion and Sediment Control Ordinance for Mathews County.[1]
[1]
Editor's Note: See Ch. 50, Erosion and Sediment Control.
G. 
All on-site sewage disposal systems not requiring a Virginia Pollutant Discharge Elimination System (VPDES) permit shall:
(1) 
Have pump-out accomplished for all such systems at least once every five years.
(2) 
If deemed appropriate by the local health department and subject to conditions the local health department may set, as an alternative to the mandatory pumpout, the option of having a plastic filter installed and maintained in the outflow pipe from the septic tank to filter solid material from the effluent while sustaining adequate flow to the drainfield to permit normal use of the septic system. Such a filter should satisfy standards established in the Sewage Handling and Disposal Regulations (12 VAC 5-610) administered by the Virginia Department of Health.
(3) 
In lieu of requiring proof of septic tank pump-out every five years, owners of on-site sewage treatment systems to submit documentation every five years, certified by sewage handler permitted by the Virginia Department of Health, that the septic system has been inspected, is functioning properly, and the tank does not need to have the effluent pumped out of it.
H. 
For new construction, a reserve sewage disposal site with a capacity at least equal to that of the primary sewage disposal site shall be provided and must meet the approval of the Sanitarian employed by the State Health Department assigned to Mathews County. This requirement shall not apply to any lot or parcel recorded prior to October 1, 1989, nor shall it apply to any lot or parcel on which construction has been lawfully commenced and a sewage disposal permit has been issued prior to the effective date of Article 22 of this chapter, if such lot or parcel is not sufficient in capacity to accommodate a reserve sewage disposal site, as determined by the Sanitarian. Building or construction of any impervious surface shall be prohibited on the area utilized by, or reserved for, sewage disposal sites until such time as the structure is served by public sewer or an onsite sewage treatment system which operates under a VPDES permit. All sewage disposal site records shall be administered to provide adequate notice and enforcement of this provision.
I. 
For any use or development, stormwater runoff shall be controlled by the use of best management practices consistent with the water quality protection provisions of the Virginia Stormwater Management Regulations (4 VAC 3-20-10 et seq.). Stormwater management criteria which satisfy the following requirements shall apply.
(1) 
For development, the post-development non-point source pollution runoff load shall not exceed the pre-development load based on the calculated average land cover condition for Virginia's Chesapeake Bay Watershed, which is 16%, and the calculated average total phosphorus loading for Virginia's Chesapeake Bay Watershed, which is 0.45 pounds per acre per year.
(2) 
Redevelopment of any site not served by water quality best management practices as of the effective date of this article shall achieve at least a ten-percent reduction of non-point source pollution in runoff compared to the existing runoff load from the site.
(3) 
Post-development runoff from any site to be redeveloped that is served by water quality best management practices as of the date of proposed redevelopment, shall not exceed the existing load of non-point source pollution in surface runoff, provided that:
(a) 
Runoff pollutant loads must have been calculated and the best management practices employed for the expressed purpose of controlling non-point source pollution.
(b) 
If best management practices are structural, evidence shall be provided that such facilities are currently in good working order and performing at the design levels of service. The Administrator may require a review of both the original structural design and maintenance plans to verify compliance with these provisions, and a new maintenance agreement may be required to ensure compliance.
(4) 
For any redevelopment, both the pre-development and post-development pollutant loads shall be calculated by similar procedures. Where the design data is available, the original post-development non-point source pollution loads may be substituted for the existing development loads.
(5) 
Any maintenance, alteration, use, or improvement to an existing structure, which does not degrade the quality of surface water discharge, as determined by the Administrator in accordance with applicable procedures and requirements of this article, may be exempted from the requirements of this Subsection I.
J. 
Land upon which agricultural activities are being conducted, including but not limited to crop production, pasture, and dairy and feed lot operations, or lands otherwise defined as agricultural land by the local government, shall have a soil and water quality assessment. Such assessments shall evaluate the effectiveness of existing practices pertaining to soil erosion and sediment control, nutrient management and management of pesticides, and where necessary, results in a plan that outlines additional practices needed to ensure that water quality protection is accomplished consistent with this article.
K. 
A water quality impact assessment shall be required in accordance with the provisions of §§ 175-22.18 through 175-22.21 of this article for any proposed land disturbance, development or redevelopment within the RPA, and for any proposed development within the RMA when required by the Administrator after determination by the Administrator that the development warrants such assessment due to the unique characteristics of the site or the intensity of the proposed development and that such assessment is necessary to determine consistency with the goals and objectives of the Act, the regulations promulgated thereunder and this chapter.
L. 
Prior to initiating grading or other on-site activities on any portion of a lot or parcel, all wetlands permits required by federal, state, and local laws and regulations or ordinances shall be obtained and evidence of such submitted to the Administrator.
A. 
The following criteria shall be applicable to all development within the resource protection area and shall supplement the general performance criteria set forth in § 175-22.10 of this article.
B. 
Development within the RPA shall be permitted only if it is water-dependent, constitutes redevelopment; or is a road or driveway crossing satisfying the conditions set forth below in Subsection B(2); or is flood control and stormwater management facility satisfying the conditions set forth in Subsection B(3).
(1) 
A new water dependent facility or expansion of an existing water dependent facility shall be permitted within the RPA only when the following conditions are met:
(a) 
It does not conflict with the comprehensive plan;
(b) 
Such facility complies with the performance criteria set forth in § 175-22.10 of this article and the buffer area criteria set forth in §§ 175-22.12 through 175-22.15 of this article, provided that any proposed encroachment into the one-hundred-foot buffer area shall be the minimum necessary to accommodate the use and shall be authorized only pursuant to and in accordance with the findings of a water quality impact assessment as required by the provisions of Division III of this article;
(c) 
Any non-water-dependent component of such facility is located outside the RPA; and
(d) 
Access to such facility shall be provided with the minimum land disturbance necessary and, where practicable, a single point of access shall be provided.
(2) 
Roads and driveways not exempt under § 175-22.47 and which, therefore, must comply with the provisions of this article, may be constructed in or across RPAs if each of the following conditions are met:
(a) 
The Administrator makes a finding that there are no reasonable alternatives to aligning the road or drive in or across the RPA;
(b) 
The alignment and design of the road or driveway are optimized, consistent with other applicable requirements, to minimize encroachment in the RPA and minimize adverse effects on water quality;
(c) 
The design and construction of the road or driveway satisfy all applicable criteria of this article, including submission of a water quality impact assessment; and
(d) 
The Administrator reviews the plan for the road or driveway proposed in or across the RPA in coordination with the plan of development requirements as required under Division IV or subdivision plan.
(3) 
Redevelopment within the RPA shall be permitted only if there is no increase in the amount of impervious cover and no further encroachment within the RPA and it shall conform to applicable stormwater management and erosion and sediment control criteria set forth in this article and the Erosion and Sediment Control Ordinance of Mathews County.[1]
[1]
Editor's Note: See Ch. 50, Erosion and Sediment Control.
(4) 
A water quality impact assessment shall be required for any land disturbance, development or redevelopment as set forth in §§ 175-22.18 through 175-22.21, inclusive, of this article.
To minimize the adverse effects of human activities on the other components of the RPA, state waters and aquatic life, a one-hundred-foot buffer area of vegetation that is effective in retarding runoff, preventing erosion, and filtering non-point source pollution from runoff shall be retained if present and established where it does not exist.
The buffer area shall be located adjacent to and landward of other RPA components and along both sides of any water bodies with perennial flow. The full buffer area shall be designated as the landward component of the RPA.
In order to maintain the functional value of the buffer area, indigenous vegetation may be removed, subject to approval by the Administrator, only to provide for reasonable sight lines, access paths, general woodlot management, and best management practices, including those that prevent upland erosion and concentrated flows of stormwater as follows:
A. 
Trees may be pruned or removed as necessary to provide site lines and vistas, provided that where removed, they shall be replaced with other vegetation that is equally effective in retarding runoff, preventing erosion, and filtering non-point source pollution from runoff.
B. 
Any path shall be constructed and surfaced so as to effectively control erosion.
C. 
Dead, diseased, or dying trees or shrubbery and noxious weeds (such as Johnson grass, kudzu, and multiflora rose) may be removed and thinning of trees may be allowed, pursuant to sound horticultural practice incorporated into locally-adopted standards.
D. 
For shoreline erosion control projects, 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 and applicable permit conditions or requirements.
When the application of the buffer area on a lot or parcel would result in the loss of a buildable area to the landowner regarding a lot or parcel recorded prior to October 1, 1989, encroachments into the buffer area may be allowed through an administrative process, subject to provision of a water quality impact assessment as required by this article and in accordance with the following criteria:
A. 
Encroachments into the buffer area shall be the minimum necessary to achieve a reasonable area for a principal structure and necessary utilities;
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 encroaching the buffer area shall be established elsewhere on the lot or parcel;
C. 
The encroachment may not extend into the seaward 50 feet of the buffer area; and
D. 
Reasonable and appropriate conditions necessary to mitigate impacts identified in the water quality impact assessment required by this section.
On agricultural lands 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. The agricultural activities may encroach into the buffer area as follows:
A. 
Agricultural activities may encroach into the landward 50 feet of the one-hundred-foot wide buffer area when at least one agricultural best management practice, which, in the opinion of the Tidewater Soil and Water Conservation District, addresses the more predominant water quality issue on the adjacent land - erosion control or nutrient management - is being implemented on the adjacent land, provided that the combination of the undisturbed buffer area and the best management practice achieves water quality protection, pollutant removal, and water resource conservation at least the equivalent of the one-hundred-foot wide buffer area. If nutrient management is identified as the predominant water quality issue, a nutrient management plan, including soil test, must be developed consistent with the Virginia Nutrient Management Training and Certification Regulations (4 VAC 5-15 et seq.) administered by the Virginia Department of Conservation and Recreation.
B. 
Agricultural activities may encroach within the landward 75 feet of the one-hundred-foot wide buffer area when agricultural best management practices which address erosion control, nutrient management, and pest chemical control, are being implemented on the adjacent land. The erosion control practices must prevent erosion from exceeding the soil loss tolerance level, referred to as "T," as defined in the National Soil Survey Handbook of November 1996 in the Field Office Technical Guide of the U.S. Department of Agriculture Natural Resource Conservation Service. A nutrient management plan, including soil test, must be developed consistent with the Virginia Nutrient Management Training and Certification Regulations (4 VAC 5-15 et seq.) administered by the Virginia Department of Conservation and Recreation. In conjunction with the remaining buffer area, this collection of best management practices shall be presumed to achieve water quality protection at least the equivalent of that provided by the one-hundred-foot wide buffer area.
C. 
The buffer area is not required for agricultural drainage ditches if the adjacent agricultural land has in place best management practices in accordance with a conservation plan approved by the Tidewater Soil and Water Conservation District.
D. 
When agricultural or silvicultural uses within the buffer area cease, and the lands are proposed to be converted to other uses, the full one-hundred-foot wide buffer area shall be reestablished. In reestablishing the buffer, management measures shall be undertaken to provide vegetation that assures the buffer functions are maintained or established.