(A) The purpose of the water quality impact assessment is to:
(1) Identify the impacts of proposed development on water quality and lands within RPAs and other environmentally sensitive lands;
(2) Ensure that, where development does take place within RPAs and other sensitive lands, it will be in a manner that will be least disruptive to the natural functions of RPAs and other sensitive lands;
(3) Protect individuals from investing funds for proposed improvements on lands not suited for such development because of high groundwater, erosion, or vulnerability to flood and storm damage;
(4) Provide for administrative relief from the terms of this section when warranted and in accordance with the requirements contained in this section; and
(5) Specify mitigation that will address water quality protection.
(B) A water quality impact assessment is required for any proposed land disturbance, development, or redevelopment within an RPA, including any buffer area modification or encroachment as provided for in § 157.159; and any development in an RMA, floodplain, area of highly erodible soils, or 20% or greater slopes.
(C) There shall be two levels of water quality impact assessments, minor and major.
(1) Minor water quality impact assessment.
(a) A minor water quality impact assessment pertains only to development within an RPA and its 100-foot buffer strip under the following conditions:
1. No more than 6,000 square feet of land disturbance; and
2. No disturbance of the seaward 50 feet of the 100-foot buffer area.
(b) A minor assessment must demonstrate that the undisturbed buffer area, enhanced vegetative plantings, and any required BMPs will result in removal of no less than 75% of sediments and 40% of nutrients from post-development stormwater runoff. It must also demonstrate that it will retard runoff, prevent erosion, and filter nonpoint source pollution the equivalent of the full undisturbed 100-foot buffer area. A minor assessment shall include a site drawing to scale, which shows the following:
1. Location of the components of the RPA, including the 100-foot buffer area;
2. Location and nature of the proposed encroachment into the buffer area, including: type of paving material; areas of clearing or grading; location of any structures, drives, or other impervious cover; and sewage disposal systems or reserve drainfield sites;
3. Type and location of proposed BMPs to mitigate the proposed encroachment;
4. If development is in an IDA, proposed measures to restore all or part of the buffer strip, if possible;
5. Location of existing vegetation on-site, including the number and type of trees and other vegetation to be removed in the buffer to accommodate the encroachment or modification; and
6. Re-vegetation plan that supplements the existing buffer vegetation in a manner that provides for pollutant removal, erosion, and runoff control.
(2) Major water quality impact assessment.
(a) 1. A major water quality impact assessment shall be required for any development that:
a. Exceeds 6,000 square feet of land disturbance within an RPA or its buffer strip;
b. Disturbs any portion of the seaward 50 feet of the 100-foot buffer area; or
c. Is located in an RMA and includes areas of floodplain, highly erodible soils, or 20% or greater slopes.
2. The information required in this division (C)(2)(a) shall be considered a minimum unless the Zoning Administrator determines that some of the elements are unnecessary due to the scope and nature of the proposed use and development of land.
(b) The following elements shall be included in the preparation and submission of a major water quality assessment:
1. All of the information required in a minor water quality impact assessment, as specified in this division (C);
2. A hydrogeological element that:
a. Describes the existing topography, soils, hydrology, and geology of the site and adjacent lands; and
b. Describes the impacts of the proposed development on topography, soils, hydrology, and geology on the site and adjacent lands.
3. Indicates the following:
a. Disturbance or destruction of wetlands and justification for such action;
b. Disruptions or reductions in the supply of water to wetland, streams, lakes, rivers, or other water bodies;
c. Disruptions to existing hydrology, including wetland and stream circulation patterns;
d. Source location and description of proposed fill material;
e. Location of dredge material and location of dumping area for such material;
f. Location of and impacts on shellfish beds, submerged aquatic vegetation, and fish spawning areas;
g. Estimation of pre- and post-development pollutant loads in runoff;
h. Estimation of percentage of increase in impervious surface on the site and types of surfacing materials used;
i. Percentage of site to be cleared for the project;
j. Anticipated duration and phasing schedule of the construction project; and
k. Listing of all requisite permits from all applicable agencies necessary to develop the project.
4. Describes the proposed mitigation measures for the potential hydrogeological impacts. Potential mitigation measures include:
a. Proposed erosion and sediment control concepts; concepts may include minimizing the extent of the cleared area, perimeter controls, reduction of runoff velocities, measures to stabilize disturbed areas, schedule and personnel for site inspection;
b. Proposed stormwater management system;
c. Creation of wetlands to replace those lost; and
d. Minimizing cut and fill.
(c) A landscape element that:
1. Identifies and delineates the location of all significant plant material on-site, including all trees six inches or greater DBH. Where there are groups of trees, stands may be outlined;
2. Describes the impacts of the development or use on the existing vegetation, including:
a. General limits of clearing, based on all anticipated improvements, including buildings, drives, and utilities;
b. Clear delineation of all trees to be removed; and
c. Description of plant species to be disturbed or removed.
3. Describes the potential measures for mitigation. Possible mitigation measures include:
a. Replanting schedule for trees and other significant vegetation removed for construction, including a list of possible plants and trees to be used;
b. Demonstration that the design of the plan will preserve, to the greatest extent possible, any significant trees and vegetation on the site and will provide maximum erosion control and overland flow benefits from such vegetation; and
c. Demonstration that indigenous plants are to be used to the greatest extent possible.
(d) Submission and review requirements.
1. Ten copies of all site drawings and other applicable information as required by divisions (C)(2)(c)1. and (C)(2)(c)2. above shall be submitted to the Zoning Administrator for review.
2. All information required in this section shall be certified as complete and accurate by a professional engineer.
3. A water quality impact assessment shall be prepared and submitted to and reviewed by the Zoning Administrator in conjunction with § 157.161.
4. As part of any major water quality impact assessment submittal, the Zoning Administrator may require review by the Chesapeake Bay Local Assistance Department (CBLAD). Upon
receipt of a major water quality impact assessment, the Zoning Administrator will determine if such review is warranted and may request CBLAD to review the assessment and respond with written comments. Any comments by CBLAD will be incorporated into the final review by the Zoning Administrator, provided that such comments are provided by CBLAD within 90 days of the request.
(e) Evaluation procedure.
1. Upon the completed review of a minor water quality impact assessment, the Zoning Administrator will determine if any proposed modification or reduction to the buffer area is consistent with the provisions of this subchapter and make a finding based upon the following criteria:
a. The necessity of the proposed encroachment and the ability to place improvements elsewhere on the site to avoid disturbance of the buffer area;
b. Impervious surface is minimized;
c. Proposed BMPs, where required, achieve the requisite reductions in pollutant loadings;
d. The development, as proposed, meets the purpose and intent of this section; and
e. The cumulative impact of the proposed development, when considered in relation to other development in the vicinity, both existing and proposed, will not result in a significant degradation of water quality.
2. Upon the completed review of a major water quality impact assessment, the Zoning Administrator will determine if the proposed development is consistent with the purpose and intent of this section and make a finding based upon the following criteria:
a. The proposed development within the RPA is water dependent;
b. The disturbance of any wetlands will be minimized;
c. The development will not result in unnecessary disruption of the hydrology of the site;
d. The development will not result in unnecessary degradation to aquatic vegetation or life;
e. The development will not result in unnecessary destruction of plant materials on the site;
f. Proposed erosion and sediment control concepts are adequate to achieve the reductions in erosion and minimize off-site sedimentation;
g. Proposed stormwater management concepts are adequate to control the stormwater runoff and achieve the required performance standard for pollutant control;
h. Proposed re-vegetation of disturbed areas will provide effective erosion and sediment control benefits;
i. The development, as proposed, is consistent with the purpose and intent of the overlay district;
j. The cumulative impact of the proposed development, when considered in relation to other development in the vicinity, both existing and proposed, will not result in a significant degradation of water quality;
k. The Zoning Administrator shall require additional mitigation where potential impacts have not been adequately addressed. Evaluation of mitigation measures will be made by the Zoning Administrator based on the criteria listed in division (C)(2)(e)1. above and this division (C)(2)(e)2; and
l. The Zoning Administrator shall find the proposal to be inconsistent with the purpose and intent of this section when the impacts created by the proposal cannot be mitigated. Evaluation of the impacts will be made by the Zoning Administrator based on the criteria listed in division (C)(2)(e)1. above and this division (C)(2)(e)2.
(1998 Code, § 66-201) (Ord. passed 9-5-2017; Ord. O-2022-01, passed 4-5-2022) Penalty, see § 10.99