Stream Buffer Variance Application Stream Buffer Protection Ordinance

Transcription

1 Report Stream Buffer Variance Application Stream Buffer Protection Ordinance Prepared for Gwinnett County Department of Planning & Development 75 Langley Drive Lawrenceville, GA August 2005 Prepared by: Quality Gwinnett Development Company 101 Developer Way Lawrenceville, GA Quality Gwinnett Development Company

2 STREAM BUFFER VARIANCE APPLICATION 1 Introduction This document and appendices shall serve to satisfy the requirements of the Stream Buffer Protection Ordinance (SBPO) of Gwinnett County for a proposed project located at the intersection of Street A and Street C near Gwinnett City, GA. The following document and appendices include the items needed to satisfy the minimum requirements for a variance request as outlined in Gwinnett County Stream Buffer Protection Ordinance with additional guidance from Chapter 9 (Stream Buffer Mitigation Bank) of the Gwinnett County Stormwater Design Manual, and the Gwinnett County Stream Buffer Variances Application Guidelines and Information. Table 1 lists the items included to complete the application. TABLE 1 Items Included to Meet Application Requirements 1 ITEM LOCATION 1. Variance Application Appendix A 2. Application Fee and Sign Deposit Appendix B 3. Letter of Intent Sections 1 and 2 4. Site Plan and Boundary Survey Appendix C (Full size and reduction) 5. Additional Plans Appendix C (Full size and reduction) 6. Additional Documentation Section 3 7. Additional Requirements/Other Information Section 3.I 1 Application requirements as outlined in Stream Buffer Variances Application Guidelines and Information (Source: Gwinnett County Department of Planning and Development) 2 Project Description The proposed project provides for the construction of approximately 400,000 square feet of new commercial office and warehouse space. The existing site is a wooded site with an intact forested riparian buffer adjacent to an intermittent stream. The drainage area of the site contributing to the downstream end of the stream on the project site is approximately 35 acres. The proposed impacts to the buffer, outlined below, will be permanent. The stream buffers will be converted from forested riparian areas to impervious and disturbed pervious areas. 3 Additional Documentation The following additional documentation (i.e., site assessment plan) includes the following information as outlined under Section 6: Additional Information in Gwinnett County Stream Buffer Variances, Application Guidelines and Information: A. Site map that includes the locations of all streams, wetlands, floodplain boundaries and other natural features; EXAMPLE VARIANCE APPLICATION VS FINALVS2.DOC 1

3 STREAM BUFFER VARIANCE APPLICATION B. A description of the shape, size, topography, slope, soils, vegetation, and other physical characteristics of the property; C. A dated site plan that shows the locations of all existing and proposed structures and other impervious cover, the limits of all existing and proposed land disturbance, both inside and outside the buffer and setback. The exact area of the buffer to be affected shall be accurately and clearly indicated; D. Documentation that the impacts to the buffer have been avoided or minimized to the fullest extent practicable; E. A calculation of the total area and length of the proposed intrusion; F. A stormwater management site plan; G. Proposed mitigation, if any, for the intrusion; H. A description of the project with details of the buffer disturbance, including estimated length of time for the disturbance and justification for why the disturbance is necessary; I. Any other reasonable information related to the project that the DPU may deem necessary to effectively evaluate the variance request; J. A copy of the USACE permit application and supporting documentation; K. A copy of the GA EPD state waters buffer variance application and supporting documentation; and, L. A buffer mitigation plan in accordance with the procedure outlined in the Gwinnett County Storm Water Design Manual. 3.A Site Map A site map showing the location of all streams, wetlands, and floodplain boundaries is provided as Exhibit 1 in Appendix C. Additionally, the stream buffer zones (0-25, 25-50, and feet) are delineated on Exhibit 1. 3.A.1 Streams There is one small stream within the proposed site as shown in Exhibit 1. The stream channel is approximately five feet wide with bank heights of approximately 4 feet. The width of the channel at the top of bank is approximately 10 feet and the total length of the stream within the proposed site is less than 1,000 feet. 3.A.2 Wetlands There are no jurisdictional wetlands on the proposed site. 3.A.3 Floodplain/Flood Hazard Areas This property does not lie within a designated flood hazard area per F.I.R.M Community Panel No B, dated August 1, There are no floodplain areas associated with a drainage area of 100 acres or more on this site. EXAMPLE VARIANCE APPLICATION VS FINALVS2.DOC 2 COPYRIGHT 2005 BY CH2M HILL, INC. COMPANY CONFIDENTIAL

4 STREAM BUFFER VARIANCE APPLICATION 3.B Site Description The proposed site is approximately 35 acres in size and is forested with moderate to steep slopes. The predominant soils are eroded clay and sandy clay loams. The site is bounded by Street C to the north, Street A to the west, and Street B to the south. Exhibit 1 shows the general topography of the site. Exhibit 2 in Appendix C shows the location and general description of the soil types present at the project site. Approximately 1,000 feet of stream lie within the proposed boundary of the project. An area of approximately 3.69 acres lies within the stream buffer and setback. The existing stream buffer is densely vegetated with hardwoods, shrubs, and other understory. 3.C Site Plan Dated site plans showing the location of all existing and proposed structures, all impervious cover, and the limits of all existing and proposed land disturbance both inside and outside the buffer and setback are provided in Appendix C. Exhibit 3 shows the limits of the impervious area for the site together with the location of the stream centerline. Exhibit 4 shows the limits of grading. Two large buildings are proposed for the project site. The structure to the south will encompass an area of approximately 309,000 square feet while the structure to the north will encompass an area of approximately 136,000 square feet. A total of 390 parking spaces will be provided to meet the minimum parking requirements for buildings of this size and purpose. The first 500 ± feet of stream and stream buffer in this area will be completely removed and a storm drain installed to convey stormwater runoff downstream to an offline detention facility before discharging to downstream receiving waters. 3.D Impact Avoidance and Minimization The disturbance to the stream buffer on the proposed site is limited to the degree possible given the size requirements of the new commercial office and warehouse space. While the proposed project could be redesigned to limit the disturbance to the stream, minimum space requirements would not be met resulting in the objective of the proposed project not being met. Exhibit 5 in Appendix C shows an alternate layout for the proposed site. Approximately 50,000 square feet of commercial and warehouse space is lost by this alternative layout. If the alternative layout were constructed, additional construction and additional impact to other sites would ultimately be required. As much as is practicable, disturbance to the stream buffer is limited with a portion of the stream buffer preserved in the existing forested condition. Also, based on an evaluation of potential sites within a five-mile radius of the proposed project site, no other site minimizes the impact to streams, wetlands, and stream buffers to the extent that the proposed site does. Exhibit 6 in Appendix C shows vacant land of about 30 acres within a two-mile radius of the proposed site. Both alternative sites (Site A and Site B) contain extensive wetlands, streams, and stream buffers that would be impacted by construction. Construction on these two sites would require a greater amount of mitigation than the currently proposed site. EXAMPLE VARIANCE APPLICATION VS FINALVS2.DOC 3 COPYRIGHT 2005 BY CH2M HILL, INC. COMPANY CONFIDENTIAL

5 STREAM BUFFER VARIANCE APPLICATION Site-specific best management practices (BMPs) have been designed to address water quality and channel protection downstream of the site. Plans for BMPs will be submitted as part of the stormwater management plan during the development plan review process. The stormwater management facility for the site has been located offline to protect the waters of the state and to preserve as much of the forested buffer as practicable. The impacts to the buffer have been avoided or minimized to the fullest extent practicable as shown in the exhibits provided in Appendix C. During construction, erosion control will be practiced following the requirements of the Georgia Erosion Control Manual to limit the amount of silt entering the stream and the area of the stream buffer to be preserved. 3.E Proposed Impacts to Stream Buffer A total of 3.69 acres of stream buffer and 1000 linear feet of stream are permanently impacted by the proposed development. See Appendix D for detailed calculations of the proposed impacts. A total 110,046 sf of forested buffer area is changed to 81,072 sf of impervious area and 28,974 sf disturbed pervous area. 3.F Stormwater Management Plan A detailed stormwater management plan for the proposed site is currently under development and will be submitted as part of the normal development plan review process. The stormwater management plan will be submitted once the stream buffer variance application is approved. 3.G Proposed Mitigation Mitigation for the proposed impact to the stream buffer will be provided by In-lieu fees as outlined in Chapter 9 of the Gwinnett County Stormwater Design Manual. Exhibit 7 in Appendix C shows the proposed impacts to existing conditions for each buffer zone (0-25, 25-50, and feet). Calculations of the water quality value are provided as Appendix D. The total impact is calculated to be water quality value units. At a cost of $23,000 per water quality value unit, the total in-lieu mitigation fee, excluding application and inspection fees is estimated to be $315, H Details of Buffer Disturbance Please see Section 2 for a description of the proposed project. Section 3.E describes the proposed impacts to the buffer and Section 3.d discussed the justification of the impacts. 3.I Other Information Appendix F contains the following items: Signed notice regarding sign posting instructions Signed notice regarding sign refund instructions Annotated SBPO Variance Application Checklist EXAMPLE VARIANCE APPLICATION VS FINALVS2.DOC 4 COPYRIGHT 2005 BY CH2M HILL, INC. COMPANY CONFIDENTIAL

6 STREAM BUFFER VARIANCE APPLICATION Record of property ownership (Requirement 18 in the SBPO Variance Application Checklist) Additional information will be provided upon request. 3.J U.S. Army Corps of Engineers (USACOE) 404 Permit Application A copy of the permit application, supporting documentation, and proposed mitigation plan as submitted to 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 is provided in Appendix E. 3.K Georgia EPD Stream Buffer Permit Application A copy of the permit application, supporting documentation, and proposed mitigation plan as submitted to the Georgia Environmental Protection Division for a variance from the state waters buffer is provided in Appendix E. 3.L Buffer Mitigation Plan A detailed buffer mitigation plan following the procedures outlined in Chapter 9 of the Gwinnett County Stormwater Design Manual will not be necessary since mitigation for the proposed impact to the stream buffer will be provided by In-lieu fees. If in the future, onsite mitigation is deemed to be feasible, a buffer mitigation plan will be submitted at that time. EXAMPLE VARIANCE APPLICATION VS FINALVS2.DOC 5 COPYRIGHT 2005 BY CH2M HILL, INC. COMPANY CONFIDENTIAL

7 Appendix A: Gwinnett County Stream Buffer Variance Application STREAM BUFFER VARIANCE APPLICATION

8 GWINNETT COUNTY Department of Planning & Development One Justice Square 446 West Crogan Street, Lawrenceville, Georgia Phone: / Fax: Variance Application Stream Buffer Variance Stream Buffer Protection Ordinance Please complete this application & submit it with all attachments as stated in the Variance Application Guidelines & Information. Please TYPE or PRINT using BLUE or BLACK ink. A variance cannot be processed unless all information accompanies the application; a variance will not be considered when actions of any property owner of a given property have created conditions of a hardship on that property. Applicant Information Property Owner Information Name Address City State Zip Phone Name Address City State Zip Phone Contact Person s Name Phone Applicant is the (please check or circle one of the following): [ ] Developer [ ] Property Owner [ ] Developer s/property Owners Agent Address of Property Subdivision or Project Name Lot & Block District, Land Lot, & Parcel (MRN) Development Type Variance Requested Please attach a copy of the completed signed checklist for a Stream Buffer Variance Steam Buffer Case No. Page 1 of 5

9 ******************************************************************************************** Applicant Certification ********************************************************************************************* The undersigned is authorized to make this application and is aware that an application or reapplication for a variance affecting the same stream segment on a property shall be heard within 12 months from the date of last action by the Board of Construction Adjustments and Appeals, and in no case may such application or reapplication be considered in less than six months from the date of last action by the Board of Construction Adjustments and Appeals (Article 4, Section 4.2.2). Signature of Applicant Date Notary Seal Typed or Printed Name & Title Signature of Notary Public Date ********************************************************************************************* Property Owner Certification ********************************************************************************************* The undersigned is the record owner of the property considered in this application and is aware that no application or reapplication for a variance affecting the same stream segment on a property shall be heard within 12 months from the date of last action by the Board of Construction Adjustments and Appeals unless such 12-month period is waived by the Board of Construction Adjustments and Appeals, and in no case may such application or reapplication be considered in less than six months from the date of last action by the Board of Construction Adjustments and Appeals (Article 4, Section 4.2.2). Signature of Property Owner Date Notary Seal Typed or Printed Name & Title Signature of Notary Public Date ********************************************************************************************* Planning & Development Use Below Only ******************************************************************************************** Date Received Received By MRN Variance Type Code Section Zoning District Commission District Hearing Date Steam Buffer Case No. Page 2 of 5

10 Appendix B: Application Fee and Sign Deposit STREAM BUFFER VARIANCE APPLICATION

11 Insert application fee and sign deposit. STREAM BUFFER VARIANCE APPLICATION

12 STREAM BUFFER VARIANCE APPLICATION Appendix C: Site Plan and Boundary Survey and Site Assessment Plan Exhibits Note: Boundary survey is also required as a part of Stream Buffer Variance Application Checklist-Item 18, Appendix F.

13

14

15

16

17

18 Legend 5 mi. Radius Impact Area Stream Alternative 1 Proposed parcel Project Number: PM.SI.02 Alternative Miles File Path: P:\GwinnettCountyGA\186971MitigationBank\Riparian Buffer Credits\CIP Review_DJvs3.mxd, Date: June 3, 2005, User: vjarrin EXHIBIT 6 IMPACT AREA STREAM BUFFER PROTECTION ORDINANCE VARIANCE APPLICATION

19

20 Appendix D: Buffer Impact Calculations STREAM BUFFER VARIANCE APPLICATION

21 Gwinnett County Stream Buffer Evaluation Tool Date: 12/1/2005 District/ Lant Lot/ Parcel: District/LandLot/Parcel Permit/ Case Number (i.e. SBV): Permit/Case Number Project Name: Proposed Project Applicant Name: Quality Gwinnett Development Company Applicant Phone Number: (555) Existing Area (square feet{sf}) Zone Type Impervious 0 SF 0 SF 0 SF 0 SF 0 SF Disturbed Pervious 0 SF 0 SF 0 SF 0 SF 0 SF Forest 34,392 SF 48,595 SF 27,059 SF 0 SF 0 SF Total 34,392 SF 48,595 SF 27,059 SF 0 SF 0 SF 110,046 SF Proposed Area (square feet{sf}) Zone Type Impervious 26,759 SF 27,254 SF 27,059 SF 0 SF 0 SF Disturbed Pervious 7,633 SF 21,341 SF 0 SF 0 SF 0 SF Forest 0 SF 0 SF 0 SF 0 SF 0 SF Total 34,392 SF 48,595 SF 27,059 SF 0 SF 0 SF 110,046 SF Buffer Impact On Site Mitigation 0.00 Mitigation Needed WQ Value Cost ($/Value) $23,000 Total Cost $315,318

22 Gwinnett County Stream Buffer Evaluation Tool Existing Impact Area (square feet{sf}) Existing Mitigation Area (square feet{sf}) Zone Zone Type Type Impervious Impervious SF SF SF SF SF Disturbed Pervious 0 SF 0 SF 0 SF Disturbed Pervious SF SF SF SF SF Forest 34,392 SF 48,595 SF 27,059 SF Forest ac ac SF SF SF Total 34,392 ac 48,595 ac 27,059 ac 110,046 SF Total 0 SF 0 SF 0 SF 0 SF 0 SF 0 SF Proposed Impact Area (square feet{sf}) Proposed Mitigation Area (square feet{sf}) Zone Zone Type (Existing>Proposed) Type (Existing>Proposed) Forest>Impervious 26,759 SF 27,254 SF 27,059 SF Impervious>Disturbed Pervious SF SF SF ac ac Forest>Disturbed Pervious 7,633 SF 21,341 SF 0 SF Disturbed Pervious>Restored Forest SF SF SF SF SF Disturbed Pervious>Impervious 0 SF 0 SF 0 SF Impervious> Restored Forest SF SF SF SF SF Total 34,392 SF 48,595 SF 27,059 SF 110,046 SF Preserved Forest ac ac SF SF SF Total 0 SF 0 SF 0 SF 0 SF 0 SF 0 SF Impact WQ Value Factor Mitigation WQ Value Factor Zone Zone Type (Existing>Proposed) Type (Existing>Proposed) Forest>Impervious Impervious Forest>Disturbed Pervious Impervious>Disturbed Pervious Disturbed Pervious>Impervious Disturbed Pervious>Restored Forest Impervious> Restored Forest Preserved Forest Water Quality Impact Value = Area * Water Quality Value Factor Water Quality Mitigation Value = Area * Water Quality Value Zone Zone Type (Existing>Proposed) Type (Existing>Proposed) Forest>Impervious 214, ,524 54,118 Forest>Disturbed Pervious 53, ,040 0 Impervious>Disturbed Pervious Disturbed Pervious>Impervious Disturbed Pervious>Restored Forest Total 267, ,564 54, ,185 Impervious> Restored Forest Preserved Forest Source: Gwinnett County Department of Public Utilities ( Total

23 STREAM BUFFER VARIANCE APPLICATION Appendix E: USACOE and GA EPD Permit Applications

24 Insert USACOE and GA EPD Permit Applications STREAM BUFFER VARIANCE APPLICATION

25 Appendix F: Additional Information STREAM BUFFER VARIANCE APPLICATION

26 GWINNETT COUNTY Department of Planning & Development One Justice Square 446 West Crogan Street Lawrenceville, Georgia Phone: Fax: NOTICE POSTING INSTRUCTIONS 1. Signs must be posted at right-of-way of main street or road on which the property bounds 2. Sing is to be mounted on hard surface that will prevent curling or bending of sign. Sign shall be free of obstructions to said main road. 3. Signs improperly displayed may be ruled as a violation to the variance process. 4. Signs will be posted and maintained more than 15 days prior to the Board of Construction, Adjustments & Appeals meeting. Steam Buffer Case No. Page 3 of 5

27 GWINNETT COUNTY Department of Planning & Development One Justice Square 446 West Crogan Street Lawrenceville, Georgia Phone: Fax: NOTICE IN ORDER TO RECEIVE A REFUND OF THE $ SIGN DEPOSIT, THIS SIGN MUST BE RETURNED TO THE DEVELOPMENT SERVICES SECTION NO MORE THAN 15 CALENDAR DAYS AFTER THE FINAL VOTE BY THE BOARD OF CONSTRUCTION, ADJUSTMENTS & APPEALS. SIGNATURE: NAME: ADDRESS: TELEPHONE: DATE: CASE NUMBER: Steam Buffer Case No. Page 4 of 5

28 GWINNETT COUNTY Department of Planning & Development One Justice Square 446 West Crogan Street Lawrenceville, Georgia Phone: Fax: NOTICE I have been given a copy of the sign posting instructions and I understand these instructions. I further understand that the sign is to be posted on or before Date: Signature: Name: Address: Telephone: Cell: Today s Date: Case Number: Steam Buffer Case No. Page 5 of 5

29 GWINNETT COUNTY STORM WATER MANAGEMENT REVIEW CHECKLIST SPBO VARIANCE APPLICATION DEVELOPMENT NAME: Quality Gwinnett Development DISTRICT/LANDLOT/PARCEL: ENGINEER: JAT FAX NUMBER/ REVIEWER: DATE: June 15,2005 COUNTY CASE #:... Please contact reviewer at with questions about the comments or to make an appointment regarding the comments. Re-review can be walked through. Re-review shall be dropped off. Type of Mitigation In-lieu of Fee If In-lieu of Fee is used fill out Part A Onsite Mitigation If on-site mitigation is used fill out Parts A and B Buffer Variance Conditions for encroachment in the 0-25 buffer may include: a. BMPS that address oil and grease in storm water runoff must be provided for parking areas in commercial development. b. Wet water quality ponds must be used in place of dry water quality ponds and water quality volume shall be based on total area draining to an on-line pond and not just the project area. BMPS must treat total area draining to BMP. Above ground water quality ponds cannot have walls. Underground water quality BMPs must be off line. c. BMPs that treat the pollutant of concern shall be used on projects located within 10 miles of a stream not meeting its designated use. For fecal coliform, approved BMPs are wet water quality ponds, wetlands, and infiltration trenches. Before onsite mitigation will be accepted as part of a development permit, the applicant must submit a detailed Buffer Mitigation Design Plan for review in accordance with the procedures outlined in CHAPTER 9 of the Gwinnett County Storm Water Design Manual. GWINNETT COUNTY SWM REVIEW CHECKLIST Variance Application Page 1 of 3 Rev0501 April 13, Gwinnett County Stream Buffer Protection Ordinance

30 PART A GENERAL VARIANCE REQUIREMENTS 1)... A dated site map that includes locations of all streams, wetlands, regulatory and FEMA floodplain boundaries and other natural features, as determined by field survey. See Section 3A and Appendix C (Exhibit 1) 2)... A description of the shape, size, topography, slope, soils, vegetation and other physical characteristics of the property. See Section 3B and Appendix C (Exhibit 1 and 2) 3)... A dated Site Assessment Plan that shows the locations of all existing and proposed structures and other impervious cover, the limits of all existing and proposed land disturbance, both inside and outside the buffer and setback. The exact area of the buffer to be affected shall be accurately and clearly indicated. See Section 3C and Appendix C 4)... Documentation that impacts to the buffer have been avoided or minimized to the fullest extent practicable. See Section 3D 5)... A calculation of the total area and length of the proposed intrusion. See Section 3E and Appendix D 6)... A stormwater management site plan, if applicable. Submitted at a later date. 7)... Proposed mitigation, if any, for the intrusion. If no mitigation is proposed, the request must include an explanation of why none is being proposed. Section 3K 8)... A description of the project, with details of the buffer disturbance, including estimated length of time for the disturbance and justification for why the disturbance is necessary. See Section 2, 3, and Appendix C (Exhibit 7) 9)... A copy of the permit application, supporting documentation, and proposed mitigation plan as submitted to 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, if applicable. See Appendix E 10)... A copy of the State buffer variance application, supporting documentation, and proposed mitigation plan as submitted to the Georgia Environmental Protection Division for a variance from the state waters buffer. See Appendix E SITE ASSESSMENT PLAN REQUIREMENTS 11)... A Site Assessment Plan in accordance with the procedure outlined in Section of the Gwinnett County Storm Water Design Manual. See Section 3 12)... The Site Assessment Plan shall be sealed and signed by a registered engineer or landscape architect currently registered in the State of Georgia. A plant ecologist, a landscape architect, a landscape restoration specialist, or other qualified profession familiar with natural communities should be consulted to complete the Site Assessment Plan. See Section 3 and Appendix C 13)... Locations of all perennial and intermittent streams, wetlands, regulatory and FEMA floodplain boundaries and other natural features, as determined by field survey. See Appendix C 14)... Each zone (0-25, 25-50, 50-75, , and ) shall be shown. See Appendix C 15)... A calculation of the mitigation required using the Gwinnett County Stream Buffer Evaluation Tool. See Appendix D 16)... Topography with a minimum of 2-foot contour intervals. See Exhibit 1 Appendix C GWINNETT COUNTY SWM REVIEW CHECKLIST Variance Application Page 2 of 3 Rev0501 April 13, Gwinnett County Stream Buffer Protection Ordinance

31 17)... Statement of compliance with State, Federal, and local regulations and necessary permits. See Appendix E 18)... Record of property ownership. 19)... Show buffer areas affected on plans at a scale of 1 =20. See Appendix C 20)... A 25-foot buffer of disturbed pervious must be created as a transition between impervious and forested areas. See Appendix C 21)... Areas that have been forested within the last 3 years are considered forested for the purpose of determining mitigation impacts. Provide a certified letter that areas claimed as disturbed pervious have not been forested in the last three years. Not Applicable 22)... Areas that are already required as a part of open space may not be used as preservation. Not Applicable 23)... Only uniform graded gravel (that does not compact) will be considered a pervious surface. A gravel surface that compacts will be considered an impervious surface. Not Applicable PART B ON SITE MITIGATION PLAN REQUIREMENTS 24)... Only forest areas in the 50-75, , ft zones may be used for preservation. 25)... If the area between 75 and 300 is used for mitigation, then the area between 50 and 75 must also be used for mitigation and the entire area between 0 and 300 placed in Conservation Easement. 26)... Areas used for preservation must be contiguous at all points along the stream with the buffer and the length as measured parallel to the stream must be equal to or greater than the width as measured perpendicular to the stream (e.g., only rectangular areas parallel to the stream for protection of the stream corridor; flag lots are not acceptable). 27)... Identification of existing conditions on the proposed restoration or preservation site to include tree lines, native woodlands, open fields, peaks or rock outcroppings, and prime agricultural land. Delineation of tree resource areas by type such as hardwoods, pines or mixed; and old and new growth.. 28)... Amount of disturbed pervious area proposed will be less than 50% of the total on-site mitigation area and must be approved by the DPU. ADDITIONAL COMMENTS 29)... 30)... GWINNETT COUNTY SWM REVIEW CHECKLIST Variance Application Page 3 of 3 Rev0501 April 13, Gwinnett County Stream Buffer Protection Ordinance