Ch9.§4-4 · City of Nowthen public records

BUILDING REGULATIONS · GRADING, DRAINAGE, AND EROSION CONTROL PLAN REQUIREMENTS

A. The Plan shall meet the criteria set forth in the most recent version of the Engineering Manual. B. Modifications to the Plan: 1\. Major amendments of the Grading, Drainage, and Erosion Control Plan shall be submitted to the City of Nowthen and shall be processed and approved, or disapproved, in the same manner as the original plans. 2\. Field modifications of a minor nature may be authorized by the City Engineer by written authorization to the permitee. (Ordinance #13, adopted April 10, 2010)   9-4-5: DESIGN REQUIREMENTS: Grading, erosion control, and sediment control practices shall be adequate to prevent transportation of sediment from the site to the satisfaction of the City Engineer. Any construction activity disturbing one (1) acre or more of land shall meet additional criteria outlined in Section 5 of this Chapter. The design shall conform to the most recent version of the Engineering Manual and as specified herein: A. Clearing and Grading: 1\. Clearing and grading of natural resources protection areas including Shoreland Overlay District, wetlands or wetland buffers shall not be permitted, except when in compliance all other Chapters of the City Code. 2\. Clearing techniques that retain natural vegetation and retain natural drainage patterns shall be used to the satisfaction of the City Engineer. 3\. Phasing shall be required on all sites disturbing greater than thirty (30) acres, with the size of each phase to be established at plan review and as approved by the City Engineer. 4\. Clearing, except that necessary to establish sediment control devices, shall not begin until all sediment control devices have been installed and have been stabilized. 5\. Proposed cut and fill slopes shall be in accordance with the Engineering Manual and in no case shall be greater than 3:1, except as approved by the City Engineer to meet other community or environmental objectives. (Ordinance 2015-04, adopted September 8, 2015) B. Erosion Control: 1\. Exposed soil (including stockpiles) must be stabilized immediately where activity has permanently or temporarily ceased on any portion of the site and will not resume for a period exceeding 14 calendar days. (Ordinance 2015-04, adopted September 8, 2015) 2\. If vegetative erosion control methods, such as seeding, have not become established within two (2) weeks, the City Engineer may require that the site be reseeded, or that a non-vegetative option be employed. 3\. On steep slopes or in drainage ways, special techniques that meet the design criteria outlined in the Engineering Manual shall be used to ensure stabilization.   4\. At the close of the construction season, the entire site must be stabilized, using a heavy mulch layer, or another method that does not require germination to control erosion. 5\. Best management practices shall be employed to prevent the blowing of dust or sediment from the site. 6\. Best management practices that divert upland runoff past disturbed slopes shall be employed. C. Sediment Controls: 1\. Sediment controls shall be provided and maintained per the Engineering Manual. All control measures shall be installed prior to commencement of any upstream construction activities. 2\. Where possible, detention basins shall be designed in a manner that allows adaptation to provide long term stormwater management. Detention basins must be cleaned after permanent erosion control measures are in place or final stabilization has been established. The design of the detention basins shall be per the Engineering Manual. 3\. Adjacent properties shall be protected by the use of a vegetated buffer strip, in combination with perimeter controls. 4\. Soil stockpiles must be stabilized or covered at the end of each work day unless a perimeter control is in place. D. Waterways and Watercourses: 1\. When a wet watercourse must be crossed regularly during construction, a temporary stream crossing shall be provided, and an approval obtained from Department of Natural Resources. 2\. When in-channel work is conducted, the channel shall be stabilized before, during and after work. 3\. All on-site stormwater conveyance channels shall be designed according to the criteria outlined in the Engineering Manual. 4\. Stabilization adequate to prevent erosion must be provided at the outlets of all pipes and paved channels. E. Construction Site Access:   1\. A temporary access road designed in compliance with the Engineering Manual shall be provided at all sites. 2\. Other measures may be required at the discretion of the City Engineer in order to ensure that sediment is not tracked onto public streets by construction vehicles, or washed into storm drains. (Ordinance #13, adopted April 10, 2010) F. Compliance with MPCA NPDES Construction Permit. (Ordinance 2015-04, adopted September 8, 2015) 1\. All projects disturbing one acre or more of land shall be in conformance with the General Permit to Discharge Stormwater Associated with Construction Activity under the National Pollutant Discharge Elimination System/State Disposal System permit issued by the Minnesota Pollution Control Agency (MPCA), including but not limited to the following: a. Stormwater Pollution Prevention Plan (SWPPP) - The applicant shall develop a SWPPP as per NPDES Construction Permit requirements. b. Temporary Sediment Basins - Where 10 or more acres of disturbed soil drain to a common location, a temporary sediment basin as per NPDES Construction Permit requirements shall be provided. C. Dewatering - turbid or sediment laden water from dewatering activities must be discharged to a temporary or permanent sediment basin or other BMP as per NPDES Construction Permit requirements. d. Waste Controls - the applicant must provide proper waste controls as per the NPFES permit. Designated concrete washout areas will be required for all construction sites in-which on-site concrete washout is proposed. e. Pipe Outlets must be provided with energy dissipation within 24 hours after connection to a surface water. f. Inspections of the construction site must be performed by a trained person at least once every 7 days during active construction and within 24 hours after a rainfall event greater than 0.5 inches as per the NPDES Construction Permit requirements.   g. Inspection reports shall be submitted to the City Engineer upon request.

Ch.9 § 4-4

Amendment history