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HomeMy WebLinkAboutAgenda - 03-17-2015 - 7eORANGE COUNTY BOARD OF COMMISSIONERS ACTION AGENDA ITEM ABSTRACT Meeting Date: March 17, 2015 Action Agenda Item No. 7 -e 1 SUBJECT: Comprehensive Plan and Unified Development Ordinance (UDO) Amendment Outline and Schedule for Impervious Surface Amendments DEPARTMENT: Planning and Inspections PUBLIC HEARING: (Y /N) No ATTACHMENT(S): 1. Amendment Outline for Impervious Surface Amendments (UDO /Zoning 2015 -01) 2. Copy of Memorandum Provided at March 3, 2015 Meeting as an Information Item INFORMATION CONTACT: Michael Harvey Planner III, (919) 245 -2597 Craig Benedict Planning Director, (919) 245 -2585 PURPOSE: To consider and approve process components and schedule for a government initiated Unified Development Ordinance (UDO) text amendment for the May 26, 2015 Quarterly Public Hearing regarding impervious surface regulations. BACKGROUND: Staff and Board members have received numerous inquiries related to increasing allowable impervious surface area including: • Increasing allowable impervious surface percentages in Watershed Protection Overlay Districts consistent with State provisions, • Allow additional impervious surface area on property based on the installation of a stormwater feature, commonly referred to as a best management practice (BMP), and • Modify the County's definition of impervious surface area to exempt gravel from being considered an `impervious surface area'. Staff provided the BOCC with an information item at its March 3, 2015 regular meeting summarizing the issues and requesting direction on possible solutions. Please refer to Attachment 2 for a copy of this memo. Since then staff has received the following direction: a. Continue to develop amendments to existing subdivision regulations requiring developers to address the comprehensive impact of development with respect to impervious surface limits and stormwater management. b. Recognize the State program that allows local property owners to use permeable pavement in order to obtain a percentage increase in allowable impervious surface area. Under the State policies, if a property owner installed 3,000 square feet of permeable concrete (i.e. driveway and parking pad) on a parcel, the State would allow for an additional percentage of impervious surface area on the property ranging from 50 to 75 % (i.e. 1,500 to 2,250 square feet of additional impervious surface area). STAFF COMMENT: The percentage of allowable impervious surface area is based on soil composition and is handled on a case -by -case basis. It should be noted due to the clay composition of soils in the County the majority of property owners may only see an allowance of 50% additional impervious surface area through this process. c. Amend the UDO incorporating this program into our `options' for obtaining additional impervious surface area on a parcel of property. STAFF COMMENT: There will be a requirement that the property owner assume the financial responsibility for the perpetual upkeep and maintenance of the stormwater system. This will include inspection of the system by local officials and the certification the system is still operational by an engineer in accordance with State policies. The proposed amendment seeks to incorporate the permeable concrete allowance within the UDO. For more background information please refer to Section B.1 of Attachment 1. Staff is still seeking direction from the BOCC on the following the need to establish impervious surface limit(s) on those areas of the County not located within a Watershed Protection Overlay District. FINANCIAL IMPACT: Consideration and approval will not create the need for additional funding for the provision of County services. Costs for the required legal advertisement will be paid from FY2014 -15 Departmental funds budgeted for this purpose. Existing Planning staff included in the Departmental staffing budget will accomplish the work required to process this amendment. RECOMMENDATION(S): The Manager recommends the Board: 1. Approve the attached Amendment Outline form; 2. Direct staff to proceed accordingly; and 3. Provide feedback on the need to establish a County wide impervious surface limit in those areas of the County not located within a watershed protection overlay district. Attachment 1 COMPREHENSIVE PLAN / FUTURE LAND USE MAP AND UNIFIED DEVELOPMENT ORDINANCE (UDO) AMENDMENT OUTLINE UDO / Zoning- 2015 -02 K UDO Text Amendment(s) allowing for the modification of impervious surface area within Watershed Protection Overlay Districts through the installation of permeable pavement A. AMENDMENT TYPE Map Amendments ❑ Land Use Element Map: From: To: ❑ Zoning Map- From - To ❑ Other: Text Amendments ❑ Comprehensive Plan Text- Section(s)- ❑ UDO Text: ❑UDO General Text Changes ❑UDO Development Standards ❑UDO Development Approval Processes �ection(s): 1. 4.2.8 Modifications of the Impervious Surface Ratio of the Orange County Unified Development Ordinance (UDO). ❑ Other: e 1. Purpose /Mission In accordance with the provisions of Section 2.8 Zoning Atlas and Unified Development Ordinance Amendments of the UDO, the Planning Director has initiated text amendment(s) to modify existing regulations governing processes 1 M allowing for the modification of allowable impervious surface area. There has been an increase in inquires and interest from local residents and property owners with respect to increasing allowable impervious surface area on parcels of property including: • Increasing allowable impervious surface percentages in Watershed Protection Overlay Districts in accordance with State standards, • Allow additional impervious surface area on property based on the installation of a stormwater feature, and • Exempt gravel from being considered an `impervious surface area'. Staff generated an information item on this topic, which was provided to the BOCC at its March 3, 2015 regular meeting (please refer to Attachment 2). As detailed within this information item, in certain circumstances the State allows the installation of a stormwater feature, commonly referred to as a Best Management Practice (BMP), providing an opportunity for the installation of additional impervious surface area. At this time the State only recognizes the use /installation of permeable pavement as a means of receiving additional impervious surface area on a parcel. The State is in the process of revising their policies, which could result in the expansion of the types of features allowing for an additional allotment of impervious surface area. The proposed amendment(s) seeks to incorporate the use of permeable pavement as a means of modifying allowable impervious surface area within the County. The review of these requests will have to be done on a case -by -case basis with the property owner assuming the responsibility for completing the necessary engineering studies justifying the modification as well as the responsibility for the maintenance, inspection, and upkeep of said BMP. 2. Analysis As required under Section 2.8.5 of the UDO, the Planning Director is required to: `cause an analysis to be made of the application and, based upon that analysis, prepare a recommendation for consideration by the Planning Board and the Board of County Commissioners'. The amendments are necessary to address current concerns our impervious surface limits are too restrictive and unnecessary limit development of property and to provide a mechanism for modifying said limits consistent with current State policies. Additional analysis will be part of the public hearing materials. 3. Comprehensive Plan Linkage (i.e. Principles, Goals and Objectives) Land Use Goal 4: Land development regulations, guidelines, techniques, and /or incentives that promote the integrated achievement of all Comprehensive Plan goals. 4. New Statutes and Rules N/A 2 a. PROCESS 1. TIMEFRAME /MILESTONES /DEADLINES a. BOCC Authorization to Proceed March 17, 2015 b. Quarterly Public Hearin Mav 26. 2015 c. BOCC Updates /Checkpoints March 3, 2015 — Approved of the UDO Amendment Outline Form. April 1, 2015 — Planning Board Ordinance Review Committee (ORC). May 26, 2015 — Quarterly Public Hearing. June 16, 2015 - Receive Planning Board recommendation. d. Other 2. PUBLIC INVOLVEMENT PROGRAM Mission /Scope: Public Hearing process consistent with NC State Statutes and Orange County ordinance requirements a. Planning Board Review: April 1, 2015 — Planning Board Ordinance Review Committee (ORC). June 3, 2015 — Recommendation. b. Advisory Boards: c. Local Government Review: Staff will transmit the proposed amendment to the Towns of Chapel Hill, Carrboro, and Hillsborough for courtesy review in the month of April 2015. d. Notice Requirements 3 Legal advertisement published in accordance with the provisions of the UDO. e. Outreach: ❑ General Public: ❑ Small Area Plan Workgroup: ❑ Other: 3. FISCAL IMPACT Modification of existing language will not require the outlay of additional funds by the County. Processing of the amendment shall be handled by staff utilizing existing budgeted funds. b. AMENDMENT IMPLICATIONS The amendment will allow for an additional process, in accordance with State regulations, allowing for the modification of impervious surface limits throughout the County. c. SPECIFIC AMENDMENT LANGUAGE Will be available with the quarterly public hearing materials. Primary Staff Contact: Michael D. Harvey Planning (919) 245 -2597 mharvey @orangecountync.gov 11 Attachment 2 INFORMATION ITEM Current Planning 131 W. Margaret Lane (919) 245 -2575 - Suite 201 (919) 644 -3002 (FAX) a� „,�'°��,,'4' -,,�� i E r,,,,,Mf ,,,.����,,,�� �� i -,,,�F P. O. Box 8181 www.orangecountync.gov i," ORFI I C R'. LIN0 Hillsborough, NC 27278 7 TO: Board of County Commissioners Bonnie B. Hammersley, County Manager FROM: Michael D. Harvey, Current Planning Supervisor Wesley Poole, Erosion Control /Stormwater CC: John Roberts, County Attorney James Bryan, County Attorney DATE: March 3, 2015 SUBJECT: INFORMATION ITEM — Response to Petition Impervious Surface Issues Please accept the following memorandum responding to a property owner inquiry over impervious surface allocations within Orange County. EXECUTIVE SUMMARY: The County is, for the most part, more restrictive than the State with respect to established impervious surface limits. There are no impervious surface limit(s) for properties not located within a `protected' or `critical' Watershed Protection Overlay District. There has been an increase in requests, both at a staff and elected official level, from property owners seeking additional impervious surface allotments beyond established limits. The State allows for the installation /use of a stormwater feature, commonly referred to as Best Management Practices (BMPs), allowing additional impervious surface area on a given property in certain circumstances. The use of a BMP is not, however, universally applicable throughout the County and can be limited based on soil composition, drainage, and topography. There are concerns related to establishing a program allowing for additional impervious surface area through the use of a BMP, as well as the perpetual maintenance costs of such infrastructure, causing staff to believe the option has limited viability. BACKGROUND: In accordance with NC General Statute 143 Chapter 21, Orange County adopted watershed management standards in the late 1980's early 1990's establishing regulations to prevent significant future water quality deterioration in `existing or potential future drinking water reservoirs'. This included the adoption of impervious surface limits for properties designated as being located within either `protected' or 'critical' watershed areas. Impervious surface is defined within Article 10 Definitions of the UDO as: A surface composed of any material that impedes or prevents the natural infiltration of water into the soil. Such surfaces include concrete, asphalt, and gravel surfaces. These include, but are not limited to streets and parking areas, sidewalks, patios, and structures that cover the land. Large amounts of impervious surface on a parcel of property impacts water quality by limiting the availability of undisturbed natural area allowing for the infiltration and treatment of stormwater runoff. To address this issue, the County adopted limits on the total cumulative amount of impervious surface(s) that can be developed thereby encouraging the preservation of natural area and allowing for more on -site infiltration. Impervious surface limits vary based on a properties location within a Watershed Protection Overlay District. Please refer to Attachment 1 for a chart breaking down current impervious surface limits in each district. Please note there are no impervious surface limits on those properties not located within a `protected' or 'critical' Watershed Protection Overlay District. This includes areas north of Chapel Hill, around the Town of Hillsborough, and a portion of land area within the Bingham Township. For more information on the location of various overlay districts, please refer to Attachment 2. ISSUE: Staff and Board members have received numerous inquiries related to increasing allowable impervious surface area including: • Increasing allowable impervious surface percentages in Watershed Protection Overlay Districts, • Allow additional impervious surface area on property based on the installation of a stormwater feature, and • Exempt gravel from being considered an `impervious surface area'. The County already has procedures in place, specifically contained Section 4.2.8 of the Unified Development Ordinance (UDO), allowing for a property owner to modify the allowable impervious surface area for a parcel, specifically: a. Applying for a variance STAFF COMMENT: Obtaining a variance from existing impervious surface limits is extremely difficult as the property owner has to demonstrate there is a unique hardship on the property. b. Proposing the establishment of a conservation easement on an adjacent parcel of property. This conservation easement would allow for a defined area to remain in a natural, undeveloped, state while allowing for the transfer of the impervious surface area to the subject parcel to facilitate development. 9 It should be noted in 2014 the State Legislature adopted a temporary rule eliminating certain types of gravel from being classified as an impervious surface. This rule, however, was rescinded resulting in all forms of gravel being considered an impervious surface and calculated as same. STATE ALLOWANCES: The State has produced a stormwater manual, denoting required design elements, which can be viewed at: http:t" ortal.n rar.or /web /Ir/ rr�p�.. manual. Property owners proposing a certain level of disturbance are required to comply with established stormwater provisions as detailed within the LIDO. In certain circumstances the State allows the installation of a stormwater feature, commonly referred to as a Best Management Practice (BMP), providing an opportunity for the installation of additional impervious surface area. As of the writing of this memorandum, the State recognizes only one BMP option allowing for additional impervious surface allocation, specifically: Permeable pavement - allows stormwater to infiltrate through void spaces for temporary storage and, ultimately, to be infiltrated into the soil. The total amount of additional impervious surface allotment is based on the soil type. Viability of permeable pavement is determined on a case by case basis with no guarantee(s). According to the manual, permeable pavement has the following general advantages and disadvantages: Advantages: • Replaces built upon area with materials that allow for infiltration of stormwater. • Eliminates standing water on pavement. • Helps to reduce pollutant runoff concerns from a parcel of property. Disadvantages • Without proper maintenance it can become clogged by sediment, compromising its effectiveness. • Not applicable for all site conditions. • Higher costs (i.e. installation and perpetual maintenance) County regulations, as contained in Section(s) 4.2.5 and 4.2.6 of the UDO, prohibit the use of BMPs as satisfying, or allowing for an increase in allowable, impervious surface area. UPDATE: Staff would like to offer the following: 1. Members of the Planning Department and Erosion Control /Stormwater are scheduled to review various elements of the existing stormwater program and possible use of BMPs to allow for additional impervious surface area with State officials on February 25, 2015. 2. Staff is developing potential amendment(s) to existing regulations requiring developers to address the comprehensive impact of development with respect to impervious surface limits and stormwater management. 10 Our goal is to offer an option whereby a developer of a subdivision could install the necessary infrastructure to off -set runoff from roadways and /or developed parcels thereby relieving future property owners from accepting responsibility for the installation and maintenance of individual stormwater management controls on a lot by lot basis. This, in turn, may result in additional impervious surface allocations for each proposed lot within a subdivision. We are also looking to establish a policy to address older subdivisions, developed prior to the adoption of impervious surface limits, where impervious area within roadways are calculated as being within part of individual lots. 3. Staff is looking for direction from the BOCC on the need to establish impervious surface limit(s) on those areas of the County not located within a Watershed Protection Overlay District. 4. In addressing inquiries made by Dr. Janel Sexton at the December 9, 2014 BOCC meeting, the County could: a. Amend existing impervious surface limits within the various Watershed Protection Overlay Districts to be consistent with current State allowances as detailed in Attachment 1. This would result in a net increase for some residents in the total cumulative amount of permitted impervious surface area allowed on their property. STAFF COMMENT: It would be incumbent on local property owners to work with staff to record new plats and declarations of development restrictions to reflect this increase in allowable impervious surface area. The property owner would absorb any expense in the creation of these document(s). There will be a finite number of property owners who will be able to take advantage of this provision. b. Amend the UDO to allow for the placement of additional impervious surface area on property with the installation /use of a BMP consistent with State regulations. In staff's opinion this amendment would include, at a minimum, the following elements: i. Consistent with State policy, requiring a property owner to hire an engineer to complete a stormwater assessment of the current property identifying its infiltration rates and carrying capacity. This would include the completion of a comprehensive soil assessment for the property. STAFF COMMENT: State officials have previously indicated soils in our area do not universally lend themselves to being viable candidates for the installation of a BMP and receiving additional impervious surface allotments. Lots have to be reviewed on a case -by -case basis. 11 Even if we implement the program described herein, opportunities for local property owners to participate in such a program may be limited. ii. Have an engineer develop a BMP to `treat' runoff thereby allowing for additional impervious surface. STAFF COMMENT: We would recommend the establishment of a cap on the total amount of additional impervious surface allowed per Watershed Protection Overlay District through this method. For example, we may allow for an additional 50% of impervious surface area in the University Lake Protected /Critical Watershed Protection Overlay Districts beyond the established 6% threshold (i.e. maximum of 9 %). This translates to a 2 acre parcel of property, normally allowed 5,227 sq. ft. of impervious surface area (43,560 x 2 x 0.06) to have 7,840 sq. ft. (43,560 x 2 x 0.09). iii. Establish a maintenance /inspection /certification policy where the property owner will have to ensure the perpetual viability of the approved BMP. We would also require documents to be recorded within the Orange County Registrar of Deeds office detailing same. STAFF COMMENT: This has the potential to be costly. The property owner will be required to absorb the cost of: 1. Maintaining the installed BMP, 2. The cost of an engineer's annual /bi- annual inspection certifying the BMP is working properly, and 3. The annual /bi- annual inspection by the County as required within the LIDO. iv. Review the need for the posting of a bond or a letter of credit allowing for the removal of the system, and excess impervious surface area, if the property owner fails to properly maintain the system. v. Require the property owner to record documents detailing new impervious surface limits in the Orange County Registrar of Deeds office (i.e. new subdivision plat(s), impervious surface declaration, stormwater operational /maintenance agreement, etc.). STAFF COMMENT: There are subdivisions in the County with locally established impervious surface limits enforced by a homeowners association. Unless these limits are also modified the property owner will be unable to take advantage of any County approved increase. 12 ATTACHMENT 1 — COUNTY AND STATE IMPERVIOUS SURFACE LIMITS: Watershed Overlay District Impervious Surface Limits — Residential Impervious Surface Limits — Non - residential State Allowanoes University Lake — 6% 6% Low Density Option: Protected Lots existin g p rior to April 2, Lots existin g p rior to April 2, 1990 6% limit with minimum lot size (STATE 1990 subject to sliding scale — subject to sliding scale — See of 1 acre Classified WS -II See Section 4.2.5.2 of LIDO Section 4.2.5.2 of LIDO OR Watershed Area) Density in this area is limited to Density in this area is limited to 1 ® 12% limit with minimum lot size 1 dwelling unit for every 5 acres dwelling unit for every 5 acres of of 2 acres. of property. property. Certain parcels in existence Certain parcels in existence prior High Density Option: 2 prior to October 2, 1989 qualify to October 2, 1989 qualify for a If new development exceeds low for a density bonus of a density bonus of a maximum of 5 density option, engineered maximum of 5 dwelling units for dwelling units for every 2 acres of stormwater controls required with every 2 acres of property with property with any future development limited to either 24% any future development being development being held to the 1 to 30% impervious surface area 3 held to the 1 unit for 5 acre unit for 5 acre density limit. A of 10% of the density limit. maximum watershed outside of a Critical Area can be developed up to 70% impervious with a structural BMP. University Lake — 6% 6% SAME AS ABOVE Critical Lots existing prior to April 2, Lots existing prior to April 2, 1990 (STATE 1990 subject to sliding scale — subject to sliding scale — See Classified WS-11 See Section 4.2.5.2 of LIDO Section 4.2.5.2 of UDO Watershed Area) Density in this area is limited to Density in this area is limited to 1 1 dwelling unit for every 5 acres dwelling unit for every 5 acres of of property. property. Certain parcels in existence Certain parcels in existence prior prior to October 2, 1989 qualify to October 12, 1989 qualify for a for a density bonus of a density bonus of a maximum of 5 maximum of 5 dwelling units for dwelling units for every 2 acres of every 2 acres of property with property with any future any future development being development being held to the 1 held to the 1 unit for 5 acre unit for 5 acre density limit. density limit. 1 Property within the University Lake Protected and Critical Watershed Protection Overlay Districts is also located within the Rural Buffer (RB) general use zoning district. In developing the RB zoning district, which was done prior to the development and adoption of Watershed Overlay standards, the County chose to require a 2 acre minimum lot size. We then chose to impose the more restrictive impervious surface limit in an effort to ensure the protection of the Chapel Hill /Carrboro water source. Z There was a conscious decision made as reflected in the Joint Planning Land Use Plan, Joint Planning Land Use Plan Agreement, and adopted 2030 Comprehensive Plan to keep the area within the RB zoning district at a low density. Changing this policy will require the amendment of the aforementioned document(s). Non - residential development(s) are held to the 6% impervious surface limit. 3 Critical areas, under high density, are limited to 24% while protected areas are limited to 30% impervious surface. 13 Watershed Overlay District Impervious Surface Limits — Residential Impervious Surface Limits — Non - residential State Allowances Cane Creek — 6% 4 12% Low Density Option: Protected Lots existing prior to January 1, Lots existing prior to January 1, ® 6% limit with minimum lot size 1994 subject to sliding scale — 1994 sliding scale — See Section of 1 acre (STATE Classified WS -II See Section 4.2.5.2 of UDO 4.2.5.2 of UDO OR Watershed Area) Density in this area is limited to 5 acre minimum lot size 12% limit with minimum lot size 1 dwelling unit for every 5 acres 50% impervious surface limit for all of 2 acres of property. fire stations and solid waste High Density Option: Certain parcels in existence collection centers (with stormwater If new development exceeds low prior to October 19, 1999 feature) density option, engineered qualify for a density bonus of a stormwater controls required with maximum of 5 dwelling units for development limited to either 24% every 2 acres of property with to 30% impervious surface area any future development being held to the 1 unit for 5 acre A maximum of 10% of the density limit. watershed outside of a Critical Area can be developed up to 70% impervious with a structural BMP. Cane Creek — 6% 6% SAME AS ABOVE Critical Lots existing prior to April 2, 5 acre minimum lot size (STATE 1990 subject to sliding scale — Lots existing prior to April 2, 1990 Classified WS -II See Section 4.2.5.2 of UDO subject to sliding scale — See Watershed Area) Density in this area is limited to Section 4.2.5.2 of LIDO 1 dwelling unit for every 5 acres of property. Certain parcels in existence prior to October 19, 1999 qualify for a density bonus of a maximum of 5 dwelling units for every 2 acres of property with any future development being held to the 1 unit for 5 acre density limit. 4 The Cane Creek Protected Watershed Protection Overlay District originally had a 12% impervious surface limit for residential developments. It appears to have been changed to be consistent with State standards. 5 There is no High Density Option currently available in the Cane Creek Critical Watershed Protection Overlay District. 14 Watershed Impervious Surface Limits — Impervious Surface Limits — State Allowanoes Overlay District Residential Non- residential Upper Eno — 12% for properties outside of 70 % in Economic Development, Low Density Option: Protected 6, 7 Transition Areas Commercial, and Commercial ® 6% limit with minimum lot size 30% for properties located Industrial Transition Activity Nodes of 1 acre (STATE within Transition Areas where with development of a BMP. Classified WS -II density exceeds 1 dwelling unit 50% for all fire stations /solid waste OR Watershed Area) per acre collection centers outside of these ® 12% limit with minimum lot size 70% for residential land uses Activity Nodes with development of of 2 acres developed at'high densities' a BMP High Density Option: (R -5, R -8, R -13). A BMP shall 12% for all other non - residential If new development exceeds low be required in this scenario development outside of Activity density option, engineered Density in this area is based on Nodes. stormwater controls required with underlying general use zoning development limited to either 24% designation to 30% impervious surface area A maximum of 10% of the watershed outside of a Critical Area can be developed up to 70% impervious with a structural BMP. Upper Eno — 6% 6% limit SAME AS ABOVE Critical a Density in this area is limited to 2 acre minimum lot size (STATE 1 dwelling unit for every 2 acres Classified WS -II of property. Watershed Area) Lots smaller than 5 acres existing prior to 6/1/2010 subject to sliding scale — See Section 4.2.5.2 of UDO Little River — 6% 2 acre minimum lot size SAME AS ABOVE Protected Lots existing prior to January 1, 50% for all fire stations /solid waste 1994 subject to sliding scale — collection centers outside of these (STATE See Section 4.2.5.2 of LIDO Activity Nodes with development of Classified WS -II a BMP Watershed Area) Density in this area is limited to 12% for all other non - residential 1 dwelling unit for every 2 acres development. of property. 6 Per Section 4.2.4 and 4.2.5 of the UDO a structural BMP is required in some cases where density exceeds 1 dwelling unit per acre. The County chose to institute the High Density Option within the Upper Eno Protected Watershed Protection Overlay District. 8 The County's Upper Eno Critical Watershed Overlay District is larger than the State recognized critical area. 15 Watershed Overlay District Impervious Surface Limits — Residential Impervious Surface Limits — Non - residential State Allowances Back Creek — 12% for properties outside of 70 % in Economic Development, Low Density Option: Protected Transition Areas Commercial, and Commercial ® 6% limit with minimum lot size 30% for properties located Industrial Transition Activity Nodes of 1 acre (STATE within Transition Areas where with development of a BMP. Classified WS -II density exceeds 1 dwelling unit 50% for all fire stations /solid waste OR Watershed Area per acre p collection centers outside of these 12% limit with minimum lot size 70% for residential land uses Activity Nodes with development of of 2 acres developed at'high densities' a BMP High Density Option: (R -5, R -8, R -13). A BMP shall 12% for all other non - residential If new development exceeds low be required in this scenario development outside of Activity Nodes. density option, engineered Density in this area is based on stormwater controls required with underlying general use zoning development limited to either 24% designation to 30% impervious surface area A maximum of 10% of the watershed outside of a Critical Area can be developed up to 70% impervious with a structural BMP. 16 Watershed Overlay District Impervious Surface Limits — Residential Impervious Surface Limits — Non - residential State Allowances Flat River — 12% 50% for all fire stations /solid waste Low Density Option: Protected Density n this area is limited to y collection centers Density limit of 2 dwelling units (STATE 1 dwelling unit for every 40,000 12% for all other non - residential per acre or 20,000 square foot Classified WS -III sq. ft. (0.92 acres) of property. development. minimum lot excluding roadway Watershed Area) right -of -way OR ® 24% impervious surface limit for residential /non - residential developments High Density Option: If new development exceeds low density option, engineered stormwater controls required with development limited to 50% impervious surface area South Hyco 12% 50% for all fire stations /solid waste SAME AS ABOVE Creek — Density in this area is limited to collection centers Protected 1 dwelling unit for every 40,000 12% for all other non - residential (STATE sq. ft. (0.92 acres) of property. development. Classified WS -III Watershed Area) 17 Watershed Impervious Surface Limits — Impervious Surface Limits — State Allowances Overlay District Residential Non- residential Lower Eno — 24% for project with curb and 70 %, with a BMP required when Low Density Option: Protected gutter an impervious surface exceeds: Density limit of 2 dwelling units (STATE 36% for project without curb 24% for project with curb and per acre or 20,000 square foot Classified WS -IV and gutter gutter minimum lot excluding roadway Watershed Area) 70% for residential land uses OR right -of -way developed at'high densities' 36% for project without curb and OR (R -5, R -8, R -13). A B M P shall be required in this scenario gutter ®24% impervious surface limit for residential /non - residential Density in this area is based on development underlying general use zoning designation OR ® 3 dwelling units per acre OR ® 36% impervious surface limit for residential /non - residential development without curb and gutter street systems High Density Option: If new development exceeds low density option, engineered stormwater controls required with development limited to 70% impervious surface area. Jordan Lake — 24% 24% SAME AS ABOVE Protected Density in this area is based on (STATE underlying general use zoning Classified WS -IV designation Watershed Area) Haw River — 24% 24% SAME AS ABOVE Protected Density in this area is based on (STATE underlying general use zoning Classified WS -IV designation Watershed Area) Attachment 2 1 10 Orange County Watersheds N pply Watersheds: Protected unprotected Critical ier Basin Boundary itersheds 'earns inicipal Jurisdiction 3 4 � Miles = 2.75 miles replaces previous versions. County Zoning ordinance 2 adopted June 1, 2010 g & Im�tlons Ik�vlmenl d Fy Mlnam Coleman n:5tate Plane Ih American 193 ,4 D..:Nm emFec 2IX W,... Z4MI5