§ 156-06 Erosion and Sediment Control Plan.
   (A)   The City will require the submittal of a SWPPP that contains an ESCP for all projects that fall under the requirements of this chapter, except if the project qualifies for an AZPDES CGP waiver for small construction sites and a copy of the waiver is provided to the City.
   (B)   Regardless of the area disturbed, the City will require the submittal of stormwater BMPs, in accordance with the Design Criteria as defined above. The BMPs must contain the necessary control measures that will be taken to protect the MS4 if a land-disturbing activity is located within 50 feet or less from any component of the City's stormwater collection system.
   (C)   The ESCP shall include the following:
      (1)   A map identifying soil type, vegetation cover, and resources protected under other sections of this chapter. This map shall be a normal engineering scale and should be at a scale no smaller than 1"=100', and no larger than 1"=10'.
      (2)   Temporary sediment basins are preferred to serve disturbed areas of at least ten acres and must have a volume adequate to contain the runoff calculated using the local two-year, 24-hours storm, as described in Chapter 192 of the Yuma City Code, and runoff coefficient from each disturbed acre drained.
      (3)   Temporary sediment basins may be utilized in the post-construction phase as retention or detention basins provided that all sediment have been removed from beds and disposed properly.
      (4)   Temporary sediment basins shall be designed to contain the higher of the following values:
         (a)   V=CPA
            Where:   V:  Volume in cubic feet.
               C:  Runoff Coefficient as described in Chapter 192 of Yuma City Code.
               P:  2-year, 24-hour rainfall in inches.
               A:  Drainage area in acres; or
         (b)   Volume (cubic feet) =  3600 x Area (acres)
      (5)   Construction schedule prior to any site development, including stripping and clearing; rough grading; construction of utilities, infrastructure and buildings; and final grading and landscaping. The schedule shall identify the expected date on which clearing will begin, the estimated duration of exposure of cleared areas, areas of clearing, installation of temporary erosion and sediment control measures, and establishment of vegetative plantings.
      (6)   All erosion and sediment control measures necessary to meet the objectives of this chapter and any additional state or federal requirements throughout all phases of construction and after completion of development of the site. Depending on the complexity of the project, the drafting of intermediate plans may be required before starting any phases of construction.
      (7)   Calculations to show sediment loads and yields before and after the application of erosion and sediment control measures for pre-construction, during construction and post-construction phases, with the maximum permissible soil loss as five tons per acre per year. Sediment calculations may be performed using the Revised Universal Soil Loss Equation (RUSLE) or the Modified Universal Soil Loss Equation (MUSLE) or any other method adopted by the United States Department of Agriculture, Natural Resources Conservation Service.
      (8)   For development other than subdivisions, and wherever applicable, seeding mixtures and rates, types of sod, method of seedbed preparation, expected seeding dates, irrigation requirements, type and rate of lime and fertilizer application, and kind and quantity of mulching for both temporary and permanent vegetative control measures.
      (9)   Provisions for maintenance of control facilities, including easements and estimates of the cost of maintenance for post-construction stage,
      (10)   The ESCP is a part of the SWPPP required by the City.
   (D)   Modifications to the SWPPP shall be processed and approved or disapproved in the same manner as § 156-05, may be authorized by the City by written authorization to the permittee, and shall include:
      (1)   Major amendments of the SWPPP submitted to the City.
      (2)   Field modifications of a minor nature.
      (3)   A fee for each modified submittal that involves a major modification, as per the table mentioned in § 156-04.
(Ord. O2006-38, passed 6-21-06; Ord. O2021-020, passed 8-4-21)