Loading...
HomeMy WebLinkAboutAgenda - 06-19-2001-9dT,. ORANGE COUNTY BOARD OF COMMISSIONERS ACTION AGENDA ITEM AB5TRACT Meeting .Date: June 19, 2001. Action Agenda Item No. _~ SUBJECT: Legal Advertisement for August 27,_2001 Quarterly Public Hearing __ DEPARTMENT: Planning and Inspections PUBLIC HEARING: (Y/N) No ATTACHMENT(S): INFORMATION CONTACT; Craig Benedict, Planning Director, ext 2592 Legal Advertisement p. 3 Robert P. Davis, Planner III, ext 2580 Amendments to Subdivision p. 5 Regulations TELEPHONE NUMBERS: Amendments to Erosion Control p. 8 Hillsborough 732-8181 Qrdinance Chapel Hill 968-4501 Amendments to Neuse River Basin p. 24 Durham 688-7331 Rules Mebane 336-227-2031 PURPOSE: To receive authorization to submit the Quarterly Public Hearing Legal Advertisement for publication for the August 27, 2001 meeting. BACKGROUND: The next regular quarterly public hearing is scheduled for August 27, 2001. A summary of each item proposed for public hearing and the proposed text for the items is provided. Staff is available to research and answer questions prior to the public hearing. Requests: • A. Orange County Subdivision Amendments • 1. Amend Section IV-B-3 Streets a. Section N-B-.3-a, provision of streets rights~f~vay Clarify that provision of streets right-of--way includes rights-of--way for proposed future transportation facilities included in adopted local and regional transportation plans. b. Section IV-Bti3.b, provision for a coordinated street system Clarify thata coordinated street system includes: • provisions for the extension of subdivision public roads to developable adjacent lots or to connect with existing public streets; and • limited driveway access on major subdivision streets. • B. Soil Erosion and Sedimentation Control Ordinance Amendments • Amends the threshold requirements in the Cane Creek and the Upper Eno Watersheds to the same rules as University Lake Watershed. • C. Orange County Stormwater Program for Lands Within the Neuse River Basin • Fine structure for violations within the originally adopted Orange County Ordinance was inconsistent with the minimum State fines. This amendment corrects those minor inconsistencies. The amendment also makes changes in regulatory language based on recommendations from the State Attorney's General office. • D. Zoning Atlas Amendment Ann Moss Joyner petition to rezone property along Dodson's Crossroads from EC-5 to R-1. The property is identified as Bingham Township, Map 27, Part of Lot 1 (aka Lot 1 in Blueberry Hill subdivision) and contains approximately 1.05 acres more or less. FINANCIAL IMPACT; There is no financial impact associated with this decision. Advertisement costs are included in the departmental budget. RECOMMENDATION(S): Administration recommends APPROVAL of the items for the August 27, 2001 .Quarterly Public Hearing. NOTICE OF PUBLIC HEARING ORANGE COUNTY BOARD OF COMMISSIONERS A public hearing will be held in the Judge F. Gordon Battle Superior Courtroom of the New Orange County Courthouse, 106 E. Margaret Lane, Hillsborough, North Carolina, on Monday, August 27, 2001 at 7:30 PM for the purpose of giving all interested citizens an opportunity to speak for or against the following items: A. ORANGE COUNTY SUBDIVISION AMENDMENTS Purpose: To make regulatory language more readable and more specific regarding regulation requirements. 1. Amend Section N-B 3 Streets a. Section N-B,3-a, provision of streets rights~f way Clarify that provision of streets right-of--way includes rights-of--way for proposed future transportation facilities included in adapted local and regional transportation plans. b. Section N-B-3.b, provision for a coordinated street system Clarify thata coordinated street system includes: • provisions for the extension of subdivision public roads to developable adjacent lots or to connect with existing public streets; and • limited driveway access on major subdivision streets. B. SOIL EROSION AND SEDIMENTATION CONTROL ORDINANCE AMENDMENTS Pu__ rpose: To receive public comment on the proposed amendment that changes the threshold grading requirements in the Cane Creek and the Upper Eno Protected Watersheds to the same levels as the University Lake Watershed. C. ORANGE COUNTY STORMWATER PROGRAM FOR LANDS WITHIN THE NEUSE RIVER BASIN Purpose: To receive public comment on proposed amendment to the Stormwater Program adjusting the fines to the minimum levels required in the State rules, and to make regulatory language more specific based on recommendations from legal staff in the State Attorney General's office. D. ZONING ATLAS AMENDMENT Ann Moss Joyner to rezone from EC-5 to R-1 property located along the eastern side Dodson's Crossroads (SR 1102) between Timberidge Court and Overland Passage also being Bingham Township, Tax Map 27, Part of Lot 8 (aka Lot 1 of Blueberry Hills subdivision) and containing 1.05 acres more or less. Changes may be made in the advertised proposals that reflect debate, objections and discussion at the hearing. Accommodations for individuals with physical disabilities can be provided if the request is made to the Director of Planning at least 4$ hours prior to the Public Hearing by calling the appropriate number listed below. The full text of the changes may be obtained from the Planning Department. Also, the text may be obtained at the County website www.co.orange.nc.us at the Agendas and Reports link prior to the meeting. Questions regarding the proposals may be directed to the Orange County Planning Department located in the Planning and Agricultural Center, 306E Revere Road, Hillsborough, North Carolina. Office hours are from 8:00 a.m. to 5:00 p.m. Monday through Friday. You may also ca11245-2575 (Hillsborough), 688-7331 (Durham), 967- 9251 (Chapel Hill-Carrboro) or 227-2031 (Mebane/Graham). Please ask for extension 2575 or 2585. You will be directed to a stafiF member who will answer your questions. PUBLISH: News of Oranae Cha el Hill Herald August 15, 2001 August 15, 2001 August 22, 2001 August 22, 2001 5 ORANGE COUNTY BOARD OF COMMISSIONERS ORANGE COUNTY PLANNING BOARD PUBLIC HEARING AGENDA ITEM ABSTRACT Meeting Date: August 27, 2001 Action Agenda Item No. SUBJECT: Amendments to Orange County Subdivision Regulations Section IV-B-3 to Clarify Provisions for Street Rights-of-Way and Coordinated Street System DEPARTMENT: Planning PUBLIC HEARING: Y/N YES INFORMATION CONTACT: ATTACHMENT(S): Craig Benedict, ext. 2592 1. Ordinance Amending the Orange County Karen Lincoln, ext. 2594 Subdivision Regulations TELEPHONE NUMBERS: Hillsborough 732-8181 Chapel Hill 968-4501 Durham 6$8-7331 Durham 688-7331 PURPOSE: To receive citizen comment on proposed amendments to the Orange County Subdniision Regulations Section IV B-3 Streets, to clarify: 1. Section N-B~-a, provision of streets rights-af way ;and 2. Section IV B-3.b, provisian for a coordinated street system. BACKGROUND: Subdivision Regulations require provision of street rights-of--way and that all subdivisions to have "a coordinated street system via a public or private street ..". Proposed amendments would clarify: 1. Provision of streets right-of--way includes rights-of-way for proposed future transportation facilities included in adopted local and regional transportation plans. 2. A coordinated street system includes provisions for the extension of public roads in a subdivision to undeveloped adjacent lots or to connect with existing public streets; and limited driveway access on major subdivision streets. FINANCIAL IMPACT: There is no immediate financial impact associated with this decision item. RECOMMENDATION(S): The Administration recommends that the Board refer the proposed. amendments to the Planning Board for a recommendation to be returned to the Board of Commissioners by June 19, 2001. AN ORDINANCE AMENDING THE ORANGE COUNTY SUBDIVISION REGULATIONS IV-B-3 STREETS, SECTION IV-B-3-a AND SECTION IV-B-3-b THE BOARD OF COUNTY COMMISSIONERS OF ORAN~aE COUNTY ORDAINS THAT THE SUBDIVISION REGULATIONS ARE HEREBY AMENDED AS FOLLOWS: (Bold print indicates language to be added. ~*~~'~„}"~^~ ~^" print indicates language to be deleted) ORANGE COUNTY SUBDIVISION REGULATIONS, SECTION IV-B-3 STREETS, IS AMENDED TO READ A5 FOLLOWS: IV-B-3. STREETS *IV-B-3-a. The provision of street rights-of-way shall conform to and meet the *Amended requirements of such adopted Comprehensive Plan for Orange County as 4/4/88 may be recommended by the Planning Board and adopted by the Orange County Board of County Commissioners, from its date of adoption, including dedication of street rights-of-way for proposed future transportation facilities, provided that a subdivider shall ,not be required to provide or dedicate right-of--way for a proposed street to which access would be prohibited by any governmental agency. *IV-B-3-b. All subdivisions shall have a coordinated street system via a public or "Amended private street and access a public, state, or municipal street. 10/16/90 A coordinated street system shall consider the following: (a) Public street rights-of-way shall extend to adjacent properties to provide connectivity to the existing and future countywide transportation network; and (b) Lot access shall be limited on major subdivision streets that provide connectivity between two or more roads designated in the Comprehensive Plan as arterials or collectors. (eff.12/3/90) All subdivisions containing private streets shall have at least one street which intersects with or joins an extension of a public, state, or municipal street This ordinance shall become effective upon adoption. NOW THEREFORE BE IT ORDAINED by the Board of Orange County Commissioners that this Zoning Atlas Amendment is effective upon approval. Upon motion of Commissioner ;seconded by Commissioner the foregoing ordinance was adopted this the day of 2001. I, Beverly A. Blythe, Clerk to the Board of Commissioners for the County of Orange, North Carolina, DO HEREBY CERTIFY that the foregoing is a true copy of so much of the proceedings of said Board at a meeting held on , 2001 as- relates in any way to the adoption of the foregoing and that said proceedings are recorded in Minute Book No. of the minutes of said Board. WITNESS my hand and the seal of said County, this day of , 2001. Clerk to the Board of Commissioners Amendments to the Orange County Soil Erosion and Sedimentation Control Ordinance June 2001 NOTE: The bold, underlined text will be added to the Ordinance and the struck #hrough text will be deleted. Section 2.1 Findings of Fact Relating to Sedimentation and Erosion in University Lake. Cane Creek, and -Upper Eno Protected Watershed Areas The County Commissioners find that, without strict sedimentation and erasion controls, the development of land within the University Lake, Cane Creek, and Upper Eno Protected Watershed Areas will have a significant adverse impact upon the health, safety, and welfare of all persons served by the University Lake, Cane Creek and U er Eno Protected Watershed Areas. Mare specifically: A. stormwater runoff carries pollutants into University Lake,-Cane Creek and U er Eno Protected Watershed Areas, degrading water. quality. These pollutants include, but are not limited to, organic and inorganic chemicals. B. The increase in nutrients such as phosphorus and nitrogen will accelerate eutrophication of University Lake, Cane Creek, and, Upper Eno Protected Watershed Areas, adversely affecting flora and fauna. C. The improper channelization of watercourses and drainage areas in the University Lake, Cane Creek and U er Eno Protected Watershed Areas will increase the velocity of runoff, thereby increasing erosion and sedimentation. D. The alteration of the natural topography and removal of vegetation will increase erosion by increasing velocity of runoff. E. The siltation of water bodies resulting from increased erosion will decrease the capacity of the water bodies to hold and transport water, and harm flora and fauna. F. Sedimentation further reduces water quality because it transports pollutants into the water, then releases them in the water as it settles. G. Impervious surfaces will increase the. volume and rate of stormwater runoff. This allows less water to percolate into the sail, thereby decreasing groundwater recharge. Increased velocity of runoff also reduces the filtering effect of the soil. H. Improperly managed stormwater runoff will increase the incidence of flooding and the level of floods which occur. 9 Section 2,2 Objectives of Regulations Applicable to University Lake, Cane Creek, and Upper Eno Protected Watershed Areas The regulations set forth in this Ordinance applicable to the University Lake, Cane Creek, and Upper Eno Protected Watershed Areas are designed: 1. Tv protect and maintain the chemical, physical and biological quality and integrity vf~University Lake, Cane Creek, and Upper Eno Protected Watershed Areas and other critical watershed areas. 2. To prevent harm to the residents of the community by prohibiting activities which adversely affect University Lake,.Cane Creek,,and Upper Eno Protected Watershed Areas as a public water supply. 3. To encourage the protection of natural systems and the utilization of these systems in a manner which does not impair their beneficial functioning. 4. To discourage the construction of drainage systems which do not functionally approximate the natural drainage pattern. 5. To minimize sedimentation and erosion, within the watershed, and as a result, minimize the transport of sediment and pollutants to University Lake, Cane Creek, and Upper Eno Protected Watershed Areas. 6. To protect and maintain the existing habitat of fish and wildlife. 7. To prevent damage from flooding while recognizing that natural fluctuations in water levels are beneficial. 8. To protect the absorptive, purifying and retentive functions of the natural systems existing in the University Lake, Cane Creek and U er Eno Protected Watershed Areas. 9. To ensure the attainment of these objectives by requiring the approval and implementation of sedimentation and erosion control plans for all activities which may adversely affect the University Lake, Cane Creek and U er Eno Protected Watershed Areas. 10. To provide and enforce design and performance standards for control of post_development erosion and sedimentation in order to preserve the characteristics that existed in the University Lake, Cane Creek, and Upper Eno Protected Watershed Areas prior to development. 10 Section ~ Definitions As used in this Ordinance, unless the context clearly indicates otherwise, the following definitions apply: - Cane Creek Protected Wate~;rshed Area- comprises all the land area contributing water to Cane Creek . Upper. Eno ProtectedWatershed Area- comprises all the land area contributing water to the Upper Eno University Lake Protected Watershed Area - comprises all the land area contributing water to University Lake section 4 Jurisdiction and Effect Jurisdiction This ordinance shall apply within Orange County, including the municipalities of Carrboro, Hillsborough, and the portion of Mebane within Orange County, but excluding the municipal boundaries and planning extraterritorial limits of Chapel Hill. ' Effect It shall be unlawful, within the jurisdiction of this Ordinance, to engage in land- disturbing activity, except as provided herein, without first obtaining a permit as required by this Ordinance and without complying with the conditions of the issuance of said permit. Conflicts and duplications among portions of this Ordinance shall be resolved in favor of the mare stringent regulation. Whenever conflicts exist between federal, state or local laws, ordinances, or rules, the more restrictive provision shall apply. sections Scope and Exclusions (County-wide) This Ordinance shall apply to land-disturbing activities undertaken by any person, with the fallowing exclusions: 11 A. Agriculture Activities, including the breeding and grazing of livestock, undertaken an agricultural land for the production of plants and animals useful to man, including, but not limited to: 1. forages and sod craps, grains and feed crops, tobacco, cotton and peanuts; 2. dairy animals and dairy products; 3. poultry and poultry products; 4. livestock, including beef cattle, sheep, swine, horses, ponies, mules ar goats, including the breeding and grazing of any or all such animals; 5. bees and apiary products; ' 6. fur animals. B. Forestland Activities undertaken on forestland for the production and harvesting of timber and timber products and conducted in accordance with best management practices set out in Forest Pracfice Guidelines Related to Water Quality as adopted by the Department. If land-disturbing activity undertaken on forestland far the production and harvesting of timber and timber products is not conducted in accordance with Forest Practice Guidelines Related to Water Quality, the provisions of this ordinance shall apply to such activity and any related land- disturbing activity on the tract. C. Mining Activities for which a permit is required under the Mining Act of 1971, Article 7 of Chapter 74 of the General Statues. D. State Jurisdiction Those land-disturbing activities aver which the State by statute (G.S. 113A-56(a)) has exclusive regulatory jurisdiction, which are activities: (1) Conducted by the State, (2) Conducted by the United States, (3) Conducted by persons having the power of eminent domain, (4) Conducted by local governments, (5) Funded in whole or in part by the State or the United States. 12 Section 6 General Requirements for Areas Other Than University Lake, Cane Creek and U er Eno Protected Watershed Areas A. Protection of Property Person(s) conducting land disturbing activities shall take all reasonable measures to protect all public and private property from damage by such activities. This requirement shall apply to any areas to be disturbed, regardless of the size of the area to be uncovered. B. Erosion Control Plan Requirement Prior to the commencement of any land-disturbing activity that will result in the uncovering of more than 20,000 square feet of land, the person(s) conducting the land-disturbing activity must prepare and submit an Erosion Control Plan for the proposed site. The Plan must be approved and a Grading Permit obtained prior to the start of the disturbance. Section 6,'I General Requirements for University Lake, Cane Creek and Upper Eno Protected Watershed Areas A. Plan Requirement Except as otherwise provided in subsection B., an erosion and sedimentation control plan shall be prepared and filed with and approved by the Erosion Control Division prior to the commencement of any land- disturbing activity within the University Lake, Cane +Creek,_and Upper Eno Protected Watershed Areas. B. Plan Waiver The person(s) conducting the land-disturbing activity need not submit an erosion control plan if such person obtains an Erosion Control Plan Waiver Form from the Erosion Control Division. An application for this form shall be submitted and shall contain the name, address, and phone number of the developer and owner, a description and drawing of the proposed development or activity, the location of the development, and any other information requested by the Orange County Erosion Control Officer that is reasonably necessary to evaluate the proposed development. The Erosion Control Officer shall issue the Plan Waiver Form if he finds that: 1. The land-disturbing activity will not result in the uncovering of more than 10,000 square feet; and 13 2. The land-disturbing activity is not to be conducted in connection with any of the following types of developments: a. shopping centers b. industrial and commercial .facilities c. major subdivisions d. roads e. any activity involving the temporary or permanent storage (above or below ground) of any noxious, toxic, or hazardous substance, including fuel storage facilities. 3. The proposed land-disturbing activity will not: a. significantly increase ar decrease the rate or volume of surface water runoff; b. significantly contribute to the degradation of water runoff; c. have a significant adverse impact on a wetland, watercourse, or University Lake, Cane Creek, and Upper Eno Protected Watershed Areas; d. occur within a buffer area circumscribing University Lake, Cane Creek, and Upper Eno Protected Watershed Areas. C. Protection of Property Persons conducting land-disturbing activity shall take all reasonable measures to protect all public and private property from damage by such activities. This requirement shall apply to any area to be disturbed. Section 7 Basic Control Objectives An Erosion and Sedimentation Control Plan may be disapproved pursuant to Section 18 of this ordinance if the plan fails to address the fallowing control objectives: A. Identify Critical Areas On-site areas which are subject to severe erosion, and off-site areas which are especially vulnerable to damage from erosion and/or sedimentation, are to be identified and receive special attention, and appropriate mitigative measures are to be taken to protect those areas. B. Plan for Erosion Control Design the development and prepare the site plan so that the necessary sediment-trapping devices and erasion control measures can be 1~ accommodated and are accessible for main tenance and removal. -- Observe the requirements and standards in Orange County's Soil Erosion and Sediment Control Manual. C. Limit Exposed Areas All land-disturbing activities are to be planned and conducted to minimize the size of the area to be exposed at any one time. D. Limit Time of Exposure All land-disturbing activities are to be planned and conducted to limit exposure to the shortest feasible time. E. Control SurFace Water Surface water runoff originating upgrade of exposed areas should be controlled to reduce erosion and sediment Ions during the period of exposure. F. Control Sedimentation All land-disturbing activities are to be planned and conducted so as to prevent off-site sedimentation damage. G. Manage Stormwater Runoff When the increase in the peak rates and velocity of storm water runoff resulting from aland-disturbing activity is sufficient to cause accelerated erosion of the receiving watercourse, plans are to include measures to control the velocity and the rate of release at the point of discharge so as to minimize accelerated erosion of the site and increased sedimentation of the stream. section s Mandatory Design and Performance Standards for Land-Disturbing Activity No land-disturbing activity subject to the control of this Ordinance shall be undertaken except in accordance with the following mandatory standards: A. Buffer Zone 1. No land-disturbing activity during periods of construction. or improvement to land shall be permitted in proximity to a lake or natural watercourse unless a buffer zone is provided along the margin of the watercourse of sufficient width to confine visible siltation within the twenty- five percent (25%) of the buffer zone nearest the land-disturbing activity. Waters that have been classified as trout waters by the Environmental Management Commission shall have an undisturbed buffer zone 25 feet wide or of sufficient width to canine visible siltation within the twenty-five percent (25%) of the buffer zone nearest the land-disturbing activity, whichever is greater. Provided, however, that the County may approve plans which 15 include land-disturbing activity along trout waters when the duration of said disturbance would be temporary and the extent of said disturbance would be minimal. This subdivision shall not apply to aland-disturbing activity in connection with the construction of facilities to be located on, over, or under a lake or natural watercourse. Unless otherwise provided, the width of a buffer zone is measured from the edge of the water to the nearest edge of the disturbed area, with the 25 percent of the strip nearer the land- disturbing activity containing the natural or artificial means of confining visible siltation. 2. The 25 foot minimum width for an undisturbed buffer zone adjacent to designated trout waters shall be measured horizontally from the top of the bank. 3. Where a temporary and minimal disturbance is permitted as an exception by Section 8 (A) (1) of this ordinance, land-disturbing activities in the buffer zone adjacent to designated trout waters shall be limited to a maximum of 10% of the total length of the buffer zone within the tract to be distributed such that there is not more than 100 linear feet of disturbance in each 1000 linear feet of buffer zone. Larger areas may be disturbed with the written approval of the Director of the Division of Land Resources of the Department of Environment, Health, and Natural Resources. 4. No land-disturbing activity shall be undertaken within a buffer zone adjacent to designated trout waters that will cause adverse temperature fluctuations, as set forth in 15 NCAC 2B.0211 Fresh Surface Water Classification and Standards, in these waters. B. Graded Slopes and Fills The angle for graded slopes and fills shall be no greater than the angle which can be retained by vegetative cover or other adequate erosion control devices or structures. In any event, slopes left exposed will, within 30 working days of completion of any phase of grading, be planted or otherwise provided with ground cover, devices, or structures sufficient to restrain erosion. C. Ground Cover Whenever land-disturbing activity is undertaken on a tract comprising more than 20,000 square~feet, if more than 20,000 square feet are uncovered, the person conducting the land-disturbing activity shall install such sedimentation and erosion control devices and practices as are sufficient to retain the sediment generated by the land-disturbing activity within the boundaries of the tract during construction upon and development of said tract, and shall plant or otherwise provide a permanent ground cover sufficient to restrain erosion after completion of 16 construction or development. Except as provided in Sectian 8 (D) (2) (e) of this ordinance, provisions for a ground cover sufficient to restrain erosion must be accomplished within 30 working days or 120 calendar days, whichever period is shorter, following completion of construction or development. D. Design and Performance of Control Measures 1. Design Storm Except as provided in Section 8(D)(2)(b) of this, Ordinance and in the standard for sediment ponds in the Soil Erosion and Sediment Control Manual erosion and sedimentation control measures, structures, and devices shall be so planned, designed, and constructed as to provide protection from accelerated erosion and sedimentation from the calculated maximum peak rates of runoff from the ten-year frequency storm. Runoff rates shall be calculated using the procedures in the USDA Soil Conservation Service's "National Engineering Field Manual for Conservation Practices," or other calculation procedures acceptable to the Erosion Control Officer. 2. Standards for High Quality Waters In High Quality Water (HQW) zones the following design standards shall apply: a. Uncovered areas in HQW zones shall be limited at any time to a maximum total area of 20 acres within the boundaries of the tract. Only the portion of the land-disturbing activity within a HQW zone shall be governed by this section. Larger areas may be uncovered within the boundaries of the tract with the written approval of the Director of the Division of Land Resources of the Department of Environment, Health, and Natural Resources. b. Erosion and sedimentation control measures, structures, and devices within HQW zones shall be so planned, designed, and constructed to provide protection from the runoff of the 25-year storm which produces the maximum peak rate of runoff. The peak rate of runoff shall be calculated according to procedures,-in the United States Department of Agriculture Soil Canservation Service's National Engineering Field Manual for Conservation Practices or according to procedures adopted by any other agency of this state or the United States or any generally recognized organization or association. c. Sediment ponds, (also called "sediment basins") within HQW zanes shall be designed and constructed such that the pond will have a settling efficiency of at least 70% for the 40 micron (0.04 mm) size soil particle transported into the basin by the runoff of ~/ that 2-year storm which produces the maximum peak rate of runoff. The peak rate of runoff shall be calculated according to procedures in the United States Department of Agriculture Soil Conservation Service's National Engineering Field Manual for Conservation Practices or according to procedures adopted by any other agency of this state or the United States or any generally recognized organization or association. d. Newly constructed open channels in HQW zones shall be designed and constructed with side slopes no steeper than 2 _ horizontal to 1 vertical if a vegetative cover is used for stabilization unless soil conditions permit a steeper slope or where the slopes are stabilized by using mechanical devices, structural devices or other acceptable devices. In any event, the angle for side slopes shall be sufficient to restrain accelerated erosion. e. Ground cover sufficient to restrain erosion must be provided for any portion of a land- disturbing activity in a HQW zone within 15 working days or 60 calendar days, whichever period is shorter, following completion of construction or development. E. Prior. Plan Approval No person shall initiate any land-disturbing activity on a tract if more than 20,000 square feet are to be uncovered unless, thirty or more days prior to initiating the activity, an erasion and sedimentation control plan for such activity is filed with, approved by, and a Grading Permit obtained from the County. Section 8.1 Additional Standards for Land-Disturbing Activity in University Lake, Cane Creek and U er Eno Protected Watershed Areas The provisions of Section 8 shall apply to land-disturbing activity within the University Lake, Cane Creek and U er Eno Protected Watershed Areas. In addition, the design, construction, and maintenance of drainage systems in developments within the University Lake, Cane Creek, and Upper Eno Protected Watershed Areas shall also be consistent with the following standards, and these standards shall control to the extent that they are more restrictive than thane set forth in Section 8. A. Channeling Runoff -channeling runoff directly into water bodies shall be prohibited. Runoff shall be routed through swales and other systems designed to increase time of concentration, decrease velocity, increase infiltration, allow suspended solids to settle, and remove pollutants. 18 B. Alteration of Watercourses -natural watercourses shall not be dredged, cleared of vegetation, deepened, widened, straightened, stabilized or otherwise altered except in accordance with an approved erosion control plan, Water shall be retained or detained before it enters any natural watercourse in order to preserve the natural hydro-dynamics of the watercourse and to prevent sedimentation. C. Limit Land-Disturbing Activity -the area of disturbance by development shall be as small as practical. D. Land Alterations - no grading, cutting or filling shall be commenced until erosion and sedimentation control devices have been installed between the, disturbed area and water bodies, watercourses, wetlands, or adjoining properties. E. Wetland Protection -wetlands and, other water bodies shall not be used as sediment traps during development. F. Maintenance Requirements and Responsibility -erosion and sedimentation facilities shall receive regular maintenance to ensure that they continue to function properly. Temporary basins shall be cleaned out when they are filled to fifty (50) percent of their design capacity. G. Artificial Watercourses -any artificial watercourse (where the need is demonstrated) shall be designed considering soil type so that the velocity of flow is low enough to prevent accelerated erosion. H. Buffer Area Requirements -soil and pollutants carried overland, primarily from roads, trails;. and/ar land-disturbing activities, can be effectively trapped by leaving a relatively undisturbed strip of vegetation parallel and adjacent to the watercourse. Properly managed overland water flow can be directed into this buffer area in a manner that will reduce velocity and cause dispersion of the water. Sediments carried by the water will settle out as a result of this slowing and dispersion process. The width of these buffer areas shall depend on the type of stream or drainage area. The width of the buffer strips shall be as follows: 1. Creeks and tributaries - (i.e., permanent streams flowing directly into University Lake,_Cane Creek,,a,nd Upper Eno Protected Watershed Areas and permanent streams flowing into such streams). Measure along'a line running perpendicular to the edge of the floodplain (or if na floodplain has been demarcated, the center of the stream) fifty feet from the edge of the floodplain (or if no flood plain has been demarcated from the edge of the water) plus an additional distance equal to: ~. 9 4 x slope x 100 where "slope" is expressed as a percentage derived by dividing by 100 the rise in elevation between the floodplain boundary line (or if no floodplain has been demarcated, the centerline of the watercourse) and a point one hundred feet from that point along the above described perpendicular line. 2. Intermittent streams flowing into creeks and tributaries. Measure along a line running perpendicular to the centerline of the intermittent stream fifty feet from such stream centerline. 3. Intermittent streams flowing directly into University Lake, Cane Creek, and Upper Eno Protected Watershed Areas. Measure along a line running perpendicular to the centerline of the intermittent stream one hundred feet from such stream centerline. 4. Intermittent streams flowing into streams which flow directly into University Lake, Cane Creek,_and Upper Eno Protected Watershed Areas. Measure along a line running perpendicular to the centerline of the intermittent stream fifty feet from such stream centerlines. 5. University Lake, Cane Creek, and Upper Eno Protected Watershed Areas. Measure along a line running perpendicular to the high water mark or floodplain boundary (whichever is farther from the Lake) one hundred feet from such high water mark or floodplain boundary (whichever is farther from the Lake) plus an additional distance equal to: 4 x slope x 100 where "slope" is expressed as a percentage derived by dividing by 100 the rise in elevation between the high water line of the Lake and a paint one hundred feet from that point along the above described perpendicular line. The existing natural vegetation in the designated buffer areas shall not be disturbed in any way that would reduce the area's effectiveness in achieving the objectives set forth in this subsection. In addition, buffer areas from which the vegetative cover has been removed shall be planted or otherwise provided with ground cover devices or structures sufficient to allow the buffer area to accomplish the objectives set forth in .this subsection. Buffers shall not be used as temporary erosion ccntrol devices during construction. zo I. Sediment Storage -sediment shall b~ retained on the site of the development. J. Detention or Retention Areas -retention and detention ponds may be used to retain and detain the increased and accelerated runoff which the development generates. Water shall be released firom detention ponds into watercourses or wetlands at a rate and in a manner approximating the natural flow which would have occurred before development. Retention and detention ponds shall be designed so that they maintain their structural integrity when subject to a 100-year storm. Detention and retention areas shall be designed so that shorelines are sinuous rather. than straight and sv that the length of the shoreline is maximized, thus offering more space for the growth of littoral vegetation. The banks of detention and retention areas shall slope at a gentle grade into the water as a safeguard against drowning, personal injury or other accidents, to encourage the growth of vegetation and to allow the alternate flooding and exposure of the areas along the shoreline as water levels periodically rise and fall. K. open Space -the use of drainage facilities and vegetated buffer zones as open space, recreation, and conservation areas shall be encouraged. Recreational activities undertaken in these open space areas shall be limited to passive or leisure activities. L. Grassed 5wales -drainage within the development shall be accommodated by the natural. drainage systems whenever passible. The use of grassed drainageways to channel water shall be encouraged. The velocity of travel in this grassed swale shall range between 2~ feet/second. M. Retention of RunofF from Industrial Sites - On sites developed for industrial purposes (i.e., uses involving the manufacturing, processing, creating, repairing, renovating, painting, cleaning, or assembly of goods, merchandise, or equipment), retention ar detention areas meeting the standards set forth in subsection j. shall be used to insure that runoff is retained on the site before being released. The purpose of this - requirement is to insure that, not only will the standard set forth in subsection 9A. be met, but also a mechanism will be provided to safeguard the watershed against the spillage of toxic or dangerous substances. Section 9 Stormwater cutlet Protection A. Control of Discharge in University Lake,_Cane_Creek, and Upper Eno, Protected Watershed Areas Provisions shall be made for the control of Stormwater discharges far the types of development as specified below. After development of the Site, the peak discharge of Stormwater runoff resulting from aten-year storm shall be no greater than that which would result from aten-year storm on the same site prior to development. This requirement shall apply to: 1. Commercial, industrial, office, and institutional developments 2. Multi-family residential developments of more than 10 units 3. Single-family detached residential developments where more than three lots are to be created. B. Control of Velocity Persons shall plan and conduct land-disturbing activity So that the post- construction velocity of the 10-year storm -runoff in the receiving watercourse to the discharge point does not exceed the greater of: 1. the velocity established by the table in paragraph 3 of the subsection; or 2. the velocity of the 10-year storm runoff in the receiving watercourse prior to development. If conditions (1) or (2) of this paragraph cannot be met, then the receiving watercourse to and including the discharge point shall be designed and constructed to withstand the expected velocity anywhere the velocity exceeds the "prior to development" velocity by 10%. Standards 1. Acceptable Management Measures Measures applied alone or in combination to satisfy the intent of this subchapter are acceptable if there are no objectionable secondary consequences. Innovative techniques and ideas will be considered and may be used when shown to have the potential to produce successful results. Some alternatives are to: a. avoid increases in surface runoff volume and velocity by including measures to promote Infiltration to compensate for increased runoff from areas rendered impervious; 22 b. avoid increases in stormwater discharge velocities by using vegetated - or roughened swales and waterways in lieu of closed drains and high velocity paved sections; c. provide energy dissipators at outlets of storm drainage facilities to reduce flow velocities to the point of discharge; these may range from simple rip-rapped sections to complex structures; d. protect watercourses subject to accelerated erosion by improving cross sections and/or providing erosion-resistant lining. 2. Exceptions This rule shall not apply in areas other than the University Lake, Cane Creek, and Upper Eno Protected Watershed Areas where it can be demonstrated that storm water discharge velocities will not.create an erosion problem in the receiving watercourse. 3. Permissible Velocities The following is a table of permissible velocity for stormwater discharges: MATERIAL Maximum Permissible Velocities FPS MPS Fine Sand (noncolloidal) 2.5 0.8 Sandy Loam (noncolloidal) 2.5 0.8 Silt Loam (noncolloidal) 3.0 0.9 Ordinary Firm Loam 3.5 1.1 Fine Gravel 5.0 1.5 Stiff Clay (very colloidal) 5.0 1.5 Graded, Loam to Cobbles (noncolloidal) 5.0 1.5 Graded, Silt to Cobbles (colloidal) 5.5 1.7 Alluvial Silts (noncolloidal) 3.5 1.1 Alluvial Silts (colloidal) 5.0 1.5 Coarse Gravel (noncolloidal) 6.0 1.8 Cobbles .and Shingles 5.5 1.7 Shale and Hard Pans 6.0 1.8 Source: Adapted from recommendations by Special Committee on Irrigation Research, American Society of Civil Engineers, 1926, for channels with straight alignment. Far sinuous channels, multiply allowable velocity by 0.95 for slightly sinuous, by 0.9 for moderately ,sinuous channels, and by 0.8 for highly sinuous channels. Section 10 Borrow and Waste Areas 2~ When the person conducting the land-disturbing activity is also the person conducting the borrow and waste disposal activity, areas from which borrow is obtained and which are not regulated by the provisions of the Mining Act of 1971, and waste areas for surplus materials other than landfills regulated by the Department's Division of Solid Waste Management shall be considered as part of the land-disturbing activity where the borrow material. is being used or from which the waste material originated. When the person conducting the land-disturbing activity is not the person obtaining the borrow and/or disposing of the waste, these areas shall be considered a separate land-disturbing activity. Section 11 Access and Haul Roads Temporary access and haul roads, other than public roads, constructed or used in connection with any land-disturbing activity shall be considered a part of such activity. With respect to development in the University Lake1 Cane Creek,,_and Upper_Eno Protected Watershed Areas, these access and haul roads shall have gravel pads placed at the entrance of the site of aland-disturbing activity. 24 Amendments to the Orange County Soil Erosion and Sedimentation Control Ordinance June 2001 NOTE: The bold, underlined text will be added to the Ordinance and the s#~s~~g# text will be deleted. Section 2.1 Findings of Fact Relating to Sedimentation and Erosion in University Lake Cane Creek and er Eno Protected Watershed Areas The County Commissioners find that, without strict sedimentation and erosion controls, the development of land within the University Lake, Cane Creek, and Upper Eno Protected Watershed Areas will have a significant adverse impact upon the health, safety, and welfare of all persons served by the University Lake, Cane Creek, and Upper Eno Protected Watershed Areas. More specifically: A. stormwater runoff carries pollutants into University Lake, Cane Creek, and Upper Eno Protected Watershed Areas, degrading water quality. These pollutants include, but are not limited to, organic and inorganic chemicals. B. The increase in nutrients such as phosphorus and nitrogen will accelerate eutrophication of University Lake, Cane Creek, and Upper Eno Protected Watershed Areas, adversely affecting flora and fauna. C. The improper channelization of watercourses and drairiage areas in the Universi Lake Cane Creek and U er Eno Protected Watershed Areas will increase the velocity of runoff, thereby increasing erosian and sedimentation. D. The alteration of the natural topography and removal of vegetation will increase erosion by increasing velocity of runoff. E. The siltation of water bodies resulting from increased erosion will decrease the capacity of the water bodies to hold and transport water, and harm flora and fauna. F. Sedimentation further reduces water quality because it transports pollutants into the water, then releases them in the water as it settles. G. Impervious surfaces will increase the volume and rate of stormwater runoff. This allows less water to percolate into the soil, thereby decreasing groundwater recharge. Increased velocity of runoff also reduces the filtering effect of the soil. H. Improperly managed stormwater runoff will increase the incidence of flooding and the level of floods which occur. 2; Section 2.2 Objectives of Regulations Applicable to Universi Lake Cane Creek, and Upper Eno Protected Watershed Areas The regulations set forth in this Ordinance applicable to the University Lake. Cane Creek, and Upper Eno Protected Watershed, Areas are designed: To protect and maintain the chemical, physical and biological quality and integrity of University Lake, Cane Creek, and Up„per Eno Protected Watershed Areas and other critical watershed areas. 2. To prevent harm to the residents of the community by prohibiting activities which adversely affect Universi Lake Cane Creek and U er Eno Protected Watershed Areas as a public water supply. 3. To encourage the protection of natural systems and the utilization of these systems in a manner which does not impair their beneficial functioning. 4. To discourage the construction of drainage systems which do not functionally approximate the natural drainage pattern. 5. To minimize sedimentation and erosion, within the watershed, and as a result, minimize the transport of sediment and pollutants to Universi Lake, Cane Creek, and U~~er_Eno Protected Wa#ershed Areas. 6. To protect and maintain the existing habitat of fish and wildlife. 7. To prevent damage from flooding while recognizing that natural fluctuations in water levels are beneficial. $. To protect the absorptive, purifying and retentive functions of the natural systems existing in the Universi Lake Cane Creek and U er Eno Protected Watershed Areas. 9. To ensure the attainment of these objectives by requiring the approval and implementation of sedimentation and erosion control plans for all activities which may adversely affect the University Lake, Cane Creek=and Upper Eno Protected Watershed Areas. 1p. To provide and enforce design and performance standards for control of post-development erosion and sedimentation in order to preserve the characteristics that existed in the Universit~r Lake, Cane Creek, and Up ear Eno Protected_Watershed,Areas prior to development. 26 Section 2 Definitions As used in this Ordinance, unless the context clearly indicates otherwise, the following definitions apply: Cane Creek Protected Watershed Area-com rises all the land area contributin water to Cane Creek U er Eno Protected Watershed Area- com rises all the land area contributing water to the UP,per Eno University Lake Protected Watershed Area - comprises all the land area contributing water to University Lake Section 3 Jurisdiction and Effect Jurisdiction This ordinance shall apply within Orange County, including the municipalities of Carrboro, Hillsborough, and the portion of Mebane within Orange County, but excluding the municipal boundaries and planning extraterritorial limits of Chapel Hill. Effect It shall be unlawful, within the jurisdiction of this Ordinance, to engage in land- disturbing activity, except as provided herein, without first obtaining a permit as required by this Ordinance and without complying with the conditions of the issuance of said permit. Conflicts and duplications among portions of this Ordinance shall be resolved in favor of the more stringent regulation. Whenever conflicts exist between federal, state or local laws, ordinances, or rules, the more restrictive provision shall apply. z~ Section 4 Scope and Exclusions (County-wide) This Ordinance shall apply to land-disturbing activities undertaken by any person, with the following exclusions: A. Agriculture Activities, including the breeding and grazing of livestock, undertaken on agricultural land for the production of plants and animals useful to man, including, but not limited to: 1. forages and sod crops, grains and feed crops, tobacco, cotton and • peanuts; 2. dairy animals and dairy products; 3. poultry and poultry products; 4. livestock, including beef cattle, sheep, swine, horses, ponies, mules or goats, including the breeding and grazing of any or all such animals; 5. bees and apiary products; 5. fur animals. B. Forestland Activities undertaken on forestland for the production and harvesting of timber and timber products and conducted in accordance with best management practices set out in Forest Practice Guidelines Related to Water Quality as adopted by the Department. If land-disturbing activity undertaken on forestland for the production and harvesting of timber and timber products is not conducted in accordance with Forest Practice Guidelines Related to Water Quality, the provisions of this ordinance shall apply to such activity and any related land- disturbing activity on the tract. C. Mining Activities for which a permit is required under the Mining Act of 1971, Article 7 of Chapter 74 of the General Statues. D. State Jurisdiction Those land-disturbing activities over which the State by statute (G.S. 113A-56(a)) has exclusive regulatory jurisdiction, which are activities: (1) Conducted by the State, (2) Conducted by the United States, (3) Conducted by persons having the power of eminent domain, 28 (4) Conducted by local governments, (5) Funded in whale or in .part by the State or the United States. Section 5 General Requirements for Areas Other Than University Lake Cane Creek and U er Eno Protected Watershed Areas A. Protection of Property Person(s) conducting land-disturbing activities shall take all reasonable measures to protect all public and private properly from damage by such activities. This requirement shall apply to any areas to be disturbed, regardless of the size of the area to be uncovered. B. Erosion Control Plan Requirement Prior to the commencement of any land-disturbing activity that will result in the uncovering of more than 20,000 square feet of land, the person(s) conducting the land-disturbing activity must prepare and submit an Erasion Control Plan for the proposed site. The Plan must be approved and a Grading Permit obtained prior to the start of the disturbance. Section 6.1 General Requirements for University„Lake Cane Creek, ,, ,---., and U er Eno Protected Watershed Areas A. Plan Requirement Except as otherwise provided in subsection B., an erasion and sedimentation control plan, shall be prepared and filed with and approved by the Erosian Control Division prior to the commencement of any land- disturbing activity within the University Lake. Cane Creek, and Upper Eno Protected Watershed Areas. B. Plan Waiver The person(s) conducting the land-disturbing activity need not submit an erosion control plan ifi such person, obtains an Erosian Control Plan Waiver Form from the Erosian Control Division. An application for this form shall be submitted and shall contain the name, address, and phone number of the developer and owner, a description and drawing of the proposed development or activity, the location of the develapmer~t, and any other information requested by the Orange County Erosian Control Officer that z9 is reasonably necessary to evaluate the proposed development. The Erosion Control Officer shall issue the Plan Waiver dorm if he finds that: 1. The land-disturbing activity will not result in the uncovering of more than 10,000 square feet; and 2. The land-disturbing activity is not to be conducted in connection with any of the following types of developments: a. shopping centers b. industrial and commercial facilities c. major subdivisions d. roads e. any activity involving the temporary or permanent storage (above ar below ground) of any noxious, toxic, or hazardous substance, including fuel storage facilities. 3. The proposed land-disturbing activity will not: a. significantly increase or decrease the rate or volume of surface water runoff; b. significantly contribute to the degradation of water runoff; c. have a significant adverse impact on a wetland, watercourse, or University Lake,,,Cane Creek. and Upper Eno Protected Watershed Areas; d. occur within a buffer area circumscribing University Lake, Cane Creek, and Upper, Eno Protected Watershed Areas. C. Protection of Properly Persons conducting land-disturbing activity shall take all reasonable measures to protect all public and private property from damage by such activities. This requirement shall apply to any area to be disturbed. Section 6 Basic Control Objectives An Erosion and Sedimentation Control Plan may be disapproved pursuant to Section 18 of this ordinance if the plan fails to address the fallowing control objectives: A. Identify Critical Areas On-site areas which are subject to severe erosion, and off-site areas which are especially vulnerable to damage from erasion and/or sedimentation, are to be identified and receive special attention, and appropriate mitigative measures are to be taken to protect those areas. 30 B. Plan for Erosion Control Design the development and prepare the site plan so that the necessary sediment-trapping devices and erosion control measures can be accommodated and are accessible for main tenance and removal. Observe the requirements and standards in Orange County's Sail Erosion . and Sediment Cantral Manual. C. Limit Exposed Areas All land-disturbing activities are to be planned and conducted to minimize the size of the area to be exposed at any one time. D. Limit Time of Exposure All land-disturbing activities are to be planned and conducted to limit exposure to the shortest feasible time. E. Control Surface Water Surface water runoff originating upgrade of exposed areas should be controlled to reduce erosion and sediment loss during the period of exposure. F. Control Sedimentation All land-disturbing activities are to be planned and conducted so as to prevent off-site sedimentation damage. G. Manage Stormwater Runoff When the increase in the peak rates and velocity of storm water runoff resulting from gland-disturbing activity is sufficient to cause accelerated erosion of the receiving watercourse, plans are to include measures to control the velocity and the rate of release at the point of discharge so as to minimize accelerated erosion of the site grid increased sedimentation of the stream. Section 7 Mandatory Design and Performance Standards for Land-Disturbing Activity No land-disturbing activity subject to the control of this Ordinance shall be undertaken except in accordance with the fallowing mandatory standards: A. Buffer Zone 1. No land-disturbing activity during periods of construction or improvement to land shall be permitted in proximity to a lake or natural watercourse unless a buffer zone is provided along the margin of the watercourse of sufficient width to confine visible siltation within the twenty five percent (25%) of the buffer zone nearest the land-disturbing activity. Waters that 31 have been classified as trout waters by the Environmental Management Commission shall have an undisturbed buffer zone 25 feet wide or of sufficient width to confine visible siltation within the twenty-five percent (25%) of the buffer zone.nearest the land-disturbing activity, whichever is greater. Provided, however, that the County may approve plans which include land-disturbing activity along trout waters when the duration of said disturbance would be temporary and the extent of said disturbance would be minimal. This subdivision shall not. apply to gland-disturbing activity in connection with the construction of facilities to be located on, aver, or under a lake or natural watercourse. Unless otherwise provided, the width of a buffer zone is measured from the edge of the water to the nearest edge of the disturbed area, with the 25 percent of the strip nearer the land- disturbing activity containing the natural or artificial means of confining visible siltation. 2. The 25 foot minimum width for an undisturbed huffier zone adjacent to designated trout waters shall be measured horizontally from the top of the bank. 3. Where a temporary and minimal disturbance is permitted as an exception by Section 8 (A) (1) of this ordinance, land-disturbing activities in the buffer zone adjacent to designated trout waters shall be limited to a maximum of 10% of the total length of the buffer zone within the tract to be distributed such that there is not more than 100 linear feet of disturbance in each 1000 linear feet of buffer zone. Larger areas may be disturbed with the written approval of the Director of the Division of Land Resources of the Department of Environment, Health, and Natural Resources. 4. No land-disturbing activity shall be undertaken within a buffer zone adjacent to designated trout waters that will cause adverse temperature fluctuations, as set forth in 15 NCAC 2B.0211 Fresh Surface Water Classification and Standards, in these waters. B. Graded Slopes and Fills The angle for graded slopes and fills shall be no greater than the angle which can be retained by vegetative cover or other adequate erosion control devices or structures. In any event, slopes left exposed will, within 30 working days of completion of any .phase of grading, be planted or otherwise provided with ground cover, devices, or structures sufficient to restrain erasion. C. Ground Cover Whenever land-disturbing activity is undertaken on a tract comprising more than 20,000 square feet, if more than 20,000 square feet are uncovered, the person conducting the land-disturbing activity shall install 32 such sedimentation and erosion control devices and practices as are sufficient to retain the sediment generated by the land-disturbing activity within the boundaries of the tract during construction upon and development of said tract, and shall plant or otherwise provide a permanent ground cover sufficient to restrain erosion after completion of construction or development. Except as provided in Section 8 (D) (2) (e) of this ordinance, provisions for a ground cover sufficient to restrain erosion must foe accomplished within 30 working days or 120 calendar days, whichever period is shorter, following completion of construction or development. D. Design and Performance of Control Measures 1. Design Storm Except as provided in Section 8(D)(2)(b) of this Ordinance and in the standard for sediment ponds in the Soil Erosion and Sediment Control Manual erosion and sedimentation control measures, structures, and devices shall be so planned, designed, and constructed as to provide protection from accelerated erosion and sedimentation from the calculated maximum peak rates of runoff from the ten-year frequency storm. Runoff rates shall be calculated using the procedures in the USDA Soil Conservation Service's "National Engineering Field Manual for Conservation Practices;" or other calculation procedures acceptable to the Erosion Control OfFicer. 2. Standards for High Quality Waters In High Quality Water (HQW) zones the following design standards shall apply: a. Uncovered areas in HQW zones shall be limited at any time to a maximum total area of 20 acres within the boundaries of the tract. Only the portion of the land-disturbing activity within a HQW zone shall be governed by this section. Larger areas may be uncovered within the boundaries of the tract with the written approval of the Director of the Division of Land Resources of the Department of Environment, Health, and Natural Resources. b. Erosion and sedimentation control measures, structures, and devices within HQW zones shall be so planned, designed, and constructed to provide protection from the runoff of the 25-year storm which produces the maximum peak rate of runoff. The peak rate of runoff shall be calculated according to procedures in the United States Department of Agriculture Soil Conservation Service's National Engineering Field Manual for Conservation Practices or according to procedures adopted. by any other agency of this state or the United States or any generally recognized organization or association. 33 c. Sediment ponds (also called "sediment basins") within HQW zones shall be designed and constructed such that the pond will have a settling efficiency of at least 70% for the 40 micron (0.04 mm) size soil particle transported into the basin by the runoff of that 2-year storm which produces the maximum peak rate of runoff. The peak rate of runoff shall be calculated according to procedures in the United States Department of Agriculture Soil Conservation Service's National Engineering Field Manual for Conservation Practices or according to procedures adopted by any other agency of this state or the United States or any generally recognized organization or association. d. Newly constructed open channels in HQW zones shall be designed and constructed with side slopes no steeper than 2 horizontal to 1 vertical if a vegetative cover is used for stabilization unless soil conditions permit a steeper slope or where the slopes are stabilized by using mechanical devices, structural devices or other acceptable devices. In any event, the angle for side slopes shall be sufficient to restrain accelerated erosion. e. -Ground cover sufficient to restrain erosion must be provided for any portion of a land- disturbing activity in a HQW zone within 15 working days or 60 calendar days, whichever period is shorter, following completion of construction or development. E. Prior Plan Approval ~~ No person shall initiate any land-disturbing activity on a tract if more than 20,000 square feet are to be uncovered unless, thirty or more days prior to initiating the activity, an erosion and sedimentation control plan for such activity is filed with, approved by, and a Grading Permit obtained from the County. Section $.1 Additional Standards for Land-Disturbing Activity in University Lake, Cane Creek, and Upper, Eno Protected Watershed Areas The provisions of Section 8 shall apply to land-disturbing activity within the University Lake, Cane Creek, and UUaper Eno Protected Watershed Areas. In addition, the design, construction, and maintenance of drainage systems in developments within the University_Lake, Cane Creek, and Upper Eno Protected Watershed Areas shall also be consistent with the fallowing standards, and these standards shall control to the extent that they are more restrictive than those set forth in Section 8. 3~ A. Channeling Runoff -channeling runoff directly into water bodies shall be prohibited. Runoff shall be routed through swales and other systems designed to increase time of concentration, decrease velocity, increase infiltration, allow suspended solids to settle, and remove pollutants. B. Alteration of Watercourses -natural watercourses shall not be dredged, cleared of vegetation, deepened, widened, straightened, stabilized or otherwise altered except in accordance with an approved erosion control plan. Water shall be retained or detained before it enters any natural watercourse in order to preserve the natural hydro-dynamics of the watercourse and to prevent sedimentation. C. Limit Land-Disturbing Activity -the area of disturbance by development shall be as small as practical. D. Land Alterations - no grading, cutting or filling shall be commenced until erosion and sedimentation control devices have been installed between the disturbed area and water bodies, watercourses, wetlands, or adjoining properties. E. Wetland Protection -wetlands and other water bodies shall not be used as sediment traps during development. F. Maintenance Requirements and Responsibility.-erosion and sedimentation facilities shall receive regular maintenance to ensure that they continue to fiunction properly. Temporary basins shall be cleaned out when they are filled to fifty (50) percent of their design capacity. G. Artificial Watercourses -any artificial watercourse (where the need is demonstrated) shall be designed considering soil type so that the velocity of flow is low enough to prevent accelerated erosion. H. Buffer Area Requirements -soil and pollutants carried overland, primarily from roads, trails, and/or land-disturbing activities, can be effectively trapped by leaving a relatively undisturbed strip of vegetation, parallel and adjacent to the watercourse. Properly managed overland water flow can be directed into this buffer area in a manner that will reduce velocity and cause dispersion of the water. Sediments carried by the water will settle out as a result of this slowing and dispersion process. The width of these buffer areas shall depend on the type of stream or drainage area. The width of the buffer strips shall be as follows: 1. Creeks and tributaries - (i.e., permanent streams flowing directly into Universi Lake Cane Creek and U er Eno Protected Watershed Areas and permanent streams flowing into such streams). Measure along a line running perpendicular to the 35 edge of the floodplain (or if no floodplain has been demarcated, - the center of the stream) fifty feet from the edge of the floodplain (or if no flood plain has been demarcated from the edge of the water) plus an additional distance equal to: 4 x slope x 100 where "slope" is expressed as a percentage derived by dividing by 100 the rise in elevation between the floodplain boundary line (or if no floodplain has been demarcated, the centerline of the watercourse) and a point one hundred feet from that point along the above described perpendicular line. 2. Intermittent streams flowing into creeks and tributaries. Measure along a line running perpendicular to the centerline of the intermittent stream fifty feet from such stream centerline. 3. Intermittent streams flowing directly into Universi Lake Cane Creek and U er Eno Protected Watershed Areas. Measure along a line running perpendicular to the centerline of the intermittent stream one hundred feet from such stream centerline. 4. Intermittent streams flowing into streams which flow directly into University Lake., Cane Creek, ,and Upper Eno Protected Watershed Areas. Measure along a line running perpendicular to the centerline of the intermittent stream fifty feet from such stream centerlines. 5. University-Lake, Cane Creek, and Upper Eno Protected Watershed Areas. Measure along a line running perpendicular to the high water mark or floodplain boundary (whichever is farther from the Lake) one hundred feet from such high water mark ar floodplain boundary (whichever is farther from the Lake) plus an additional distance equal to: 4 x slope x 100 where "slope" is expressed as a percentage derived by dividing by 100 the rise in elevation between the high water line of the Lake and a point one hundred feet from that point along the above described perpendicular line. The existing natural vegetation in the designated .buffer areas shall not be disturbed in any way that would reduce the area's effectiveness in achieving the objectives set forth in this subsection. !n addition, buffer areas from which the vegetative 36 cover has been removed shall be planted or otherwise provided with ground cover devices or structures sufficient to allow the buffer area to accomplish the objectives set forth in this subsection. Buffers shall not be used as temporary erasion control devices during construction. I. -Sediment Storage -sediment shall be retained on the site of the development. J. Detention or Retention Areas -retention and detention ponds may be used to retain and detain the increased and accelerated runoff which the development generates. Water shall be released from detention ponds into watercourses or wetlands at a rate and in a manner approximating the natural flow which would have occurred before development. Retention and detention ponds shall be designed sa that they maintain their structural integrity when subject to a 100-year storm. Detention and retention, areas shall be designed so that shorelines are sinuous rather than straight and so that the length of the shoreline is maximized, thus offering mare space for the growth of littoral vegetation. The banks of detention. and retention areas shall slope at a gentle grade into the water as a safeguard against drowning, personal injury or other accidents, to encourage the growth of vegetation and to allow the alternate flooding and exposure of the areas along the shoreline as water levels periodically rise and fall. K. Open Space -the use of drainage facilities and vegetated buffer zones as open space, recreation, and conservation areas shall be encouraged. Recreational activities undertaken in these open space areas shall be limited to passive or leisure activities. l.. Grassed Swales -drainage within the development shall be accommodated by the natural drainage systems whenever possible. The use of grassed drainageways to channel water shall be encouraged. The - velocity of travel in this grassed swale shall range between 2-4 feet/second. M. Retention of Runoff from Industrial Sites - On sites developed for industrial purposes (i.e., uses involving the manufacturing, processing, creating, repairing, renovating, painting, cleaning, or assembly of goods, merchandise, or equipment), retention ar detention areas meeting the standards set forth in subsection j. shall be used to insure that runoff is retained on the site before being released. The purpose of this requirement is to insure that, not only will the standard set forth in 37 subsection 9A. be met, but also a mechanism will be provided to safeguard the watershed against the spillage of toxic or dangerous substances. Section 8 stormwater Outlet Protection A. Control of Discharge in University Lake, Cane Creek, and.,Upper Eno Protected Watershed Areas Provisions shall be made far the control of stormwater discharges for the types of development as specified below. After development of the site, the peak discharge of stormwater runoff resulting from aten-year storm shall be no greater than that which would result from aten-year storm on the same site prior to development. This requirement shall apply to: 1. Commercial, industrial, office, and institutional developments 2. Multi-family residential developments of more than 10 units 3. Single-family detached residential developments where mare than three lots are to be created. B. Control of Velocity Persons shall plan and conduct land-disturbing activity so that the post- construction velocity of the 10-year storm runoff in the receiving watercourse to the discharge point does not exceed the greater of:' 1. the velocity established by the table in paragraph 3 of the subsection; or 2. the velocity of the 10-year storm runoff in the receiving watercourse prior to development. If conditions (1) or (2) of this paragraph cannot be met, then the receiving watercourse to and including the discharge point shall be designed and constructed to withstand the expected velocity anywhere the velocity exceeds the "prior to development" velocity by 10%. Standards 1. Acceptable Management Measures Measures applied alone or in combination to satisfy the intent of this subchapter are acceptable if there are no objectionable secondary consequences. Innovative techniques and ideas will be considered and may be used when shown to have the potential to produce successful results. Some alternatives are to: 38 a. avoid increases in surface runoff volume and velocity by including measures to promote Infiltration to compensate for increased runoff from areas rendered impervious; b. avoid increases in stormwater discharge velocities by using vegetated or roughened swales and waterways in lieu of closed drains and high velocity paved sections; c. provide energy dissipators at outlets of storm drainage facilities to reduce flaw velocities to the point of discharge; these may range from simple rip-rapped sections to complex structures; d. protect watercourses subject to accelerated erosion by improving cross sections and/ar providing erosion-resistant lining. 2. Exceptions This rule shall not apply in areas other than the University Lake. Cane CreekLand Utaper Eno Protected Wa#ershed Areas where it can be demonstrated that storm water discharge velocities will not create an erasion problem in the receiving watercourse. 3. Permissible Velocities The following is a table of permissible velocity for stormwater discharges: MATERIAL Maximum Permissible Velocities FPS MPS Fine Sand (nancolloidal) 2.5 0.8 Sandy Loam (noncolloidal) 2.5 0.8 Silt Loam (nancolloidal) 3.0 0.9 Ordinary Firm Loam 3.5 1.1 Fine Gravel 5.0 1:5 Stiff Clay (very colloidal) 5.0 1.5 Graded, Loam to Cobbles (noncolloidal) 5.0 1.5 Graded, Silt to Cobbles (colloidal) 5.5 1.7 Alluvial Silts (noncolloidal) 3.5 1.1 Alluvial Silts (colloidal) 5.0 1.5 Coarse Gravel (noncolloidal) 6.0 1.8 Cobbles and Shingles 5.5 1.7 Shale and Hard Pans 6.0 1.8 Source: Adapted from recommendations by Special Committee on Irrigation Research; American Society of Civil Engineers, 1926, for channels with straight alignment. For sinuous channels, multiply allowable velocity by 0.95 for slightly sinuous, by 0.9 for moderately sinuous channels, and by 0.8 far highly sinuous channels. 39 SECt1O11 9 Borrow and Waste Areas When the person conducting the land-disturbing activity is also the person conducting the borrow and waste disposal activity, areas from which borrow is obtained and which are not regulated by the provisions of the Mining Act of 1971, and waste areas far surplus materials other Phan landfills regulated by the Department's Division of Solid Waste Management shall be considered as part of the land-disturbing activity where the borrow material is being used or from which the waste material originated. When the person conducting the land-disturbing activity is not the person obtaining the borrow and/or disposing of the waste, these areas shall be considered a separate land-disturbing activity. Section 10 Access and Haul Roads Temporary access and haul roads, other than public roads, constructed or used in connection with any land-disturbing activity shall be considered a part of such activity. With respect to development in the Universi Lake Cane Creek and Upper Eno Protected Watershed Areas, these access and haul roads shall have gravel pads placed at the entrance of the site of aland-disturbing activity.