Agenda - 02-25-1991 - Laserfiche WebLink

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this ordinance land-disturbing activities in the buffer zone ad'acent to Lhg&ignited trout waters shall be limited to a maximum of 109'0 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 bu er zone. Urger areas may be disturbed with the written 1ppMvaj of the Director of the Division of Land Resources of the De artment of Environment Health and Natural Resources. 4. No land-disturbing activity shall be undertaken within a buffer zone ad'aMt to designated trout waters that will cause adverse tempSrature fluctuations as set forth in 15 NCAC 2B.0211 Fresh Su ace Water Classification and Standards in these waters. COMMEIIRARY.• The buffer requirement has been revised and strengthened for trout waters. There are no trout waters in Orange County; however, according to the staff of the Sedimentation Control Commission, the references must be included for the Ordinance to conform to the State's Model. c. Ground Cover Whenever land-disturbing activity is undertaken on a tract comprising more than 20,000 square feet, if more than 20,000contiguous 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 construction or development. Exce2t as-provided in Section $ d 2 e of this ordinance provisions fora gnaund 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. COMMENTARY- This change highlights the exception in the amendment to 8 (d) (2) (e) requiring faster stabilization in High Quality Water zones. d. Design and Performance of Control Measures 1. EXC221 as Xrovided in Section $ ,,-,2 of this Ordinance and in the standard for sediment nds in the Soil Erosion and Sediment Control Magnual rosi and sedimentation control measures structures and devices shall be so planned, desi ed and constructed as to provide protection from accelerated erosion and sedimentation from the calculated maximum peak rates of runoff from the ten-vest freau2gcy storm. Runoff rates shall be calculated using the procedures in the USDA Soil Conservation Services National Engineering Field Manual for Conservation Practices,or other calculation procedures acceptable to the Erosion Control Officer. 2. In High QxPlity water zones the folio des' standards shall a 1 : a. Uncovered areas in H W zo es shall be limited at an 'me to a im total area of 20 acres Mjthin the boundaries of the tract,-QnLy the on of the land-disturb' activ' wi a HOW zone shall be overned b this section, LAMer areas ma be uncovered within the ands 'es of the tract with the written approvid of the Director of the Division of Land Resources of the Department of EnviMaMt. Health and Natural esources. b. rosion and sedimentation control measures structures and devices within HOW zones shall be so planned, designed, and constructed to nrovik mtection from the runoff of the 25- ear storm which roduces the maximum pak rate of runoff. The-Rak rate of runoff shall be calculated according to Rmpedures in the United States DMEgMa t of A culture Soil Conservation Service's National En ineerin geld Manual for Conservation PractiM or according-to RmL4dures adopted b X any other ggency agency of gpLs state or the United States or any generally M903•zed organization or association. L. Sediment ponds also called "sediment basins" within HOW zones §Wl be desigged and constructed such that the ILond will have a %ttling_.qfficjNgy o at least 70 for the 40 rQjcW 0.04 mm size soil Rygicl e trap rted into the basin hI the off of that.2-year storm which produces the maximum Rgak rate of runoff. The RMk rate of runoff shall be 4 1-15-91