§ 152.146 GRADING AND DRAINAGE.
   (A)   Stormwater drainage control standards. All grading and drainage shall be designed and developed in conformance with the requirements of the city’s current adopted Tontitown Drainage Criteria Standards.
   (B)   Notice of intent. The developer is required to follow application process for storm water prevention plans as currently required by Arkansas Department of Environmental Quality.
   (C)   Detention and retention ponds.
      (1)   Ownership and maintenance.
         (a)   Residential subdivisions. Stormwater detention and retention ponds deeded to the city by September 10, 2005 shall be owned and maintained by the city. After September 10, 2005, stormwater detention and retention ponds in new residential subdivisions shall remain under the ownership and maintenance of the property owner during development. Stormwater detention and retention ponds shall be deeded to the property owner’s association upon filing of the final plat. Maintenance of the facilities shall be the responsibility of the property owners’ association.
         (b)   Non-residential development. Ownership of stormwater detention and retention ponds in new non-residential development shall be vested in the property owner. Maintenance of the facilities shall be the responsibility of the property owner.
      2.   Platting. All new detention and retention ponds shall be shown on a final plat as a lot number and drainage easement to allow for inspection and maintenance of the outfall structure by the city. Access to the detention or retention pond shall be shown with a minimum of 18- foot wide unobstructed drainage access easement between a public street and the pond.
   (D)   Grading permits.
      (1)   Applicability. Grading permits shall be required for grading, filling, excavation or land alteration of any kind on any site one acre or more in size during the entire construction process, where such activity is not part of an approved preliminary plat or large scale development.
      (2)   Exemptions. Grading permits shall not be required for the following:
         (a)   Excavation below finish grade. Excavations below finish grade for basements, footings, swimming pools, hot tubs, septic systems, and like structures authorized by a valid building permit or retaining walls with an approved retaining wall permit.
         (b)   Cemetery graves. Cemetery graves.
         (c)   Refuse disposal. Refuse disposal sites controlled by other regulations.
      3.   Application. A separate permit shall be required for each site; it may cover both excavations and fills. Grading permits may be issued jointly for parcels of land that are contiguous, so long as erosion control measures are in place until project completion.
         (a)   Application form. Completed and signed application form.
         (b)   Fee. Payment of fee as indicated on the application.
         (c)   Grading plan. A grading plan in accordance with the specifications identified in the application and in conformance with all applicable regulations, including but not limited to, the currently adopted stormwater regulations as established by United State Environmental Protection Agency, Region VI published in the Federal Register; the city’s currently adopted Stormwater Pollution Prevention and Erosion Control Standards; and the city’s currently adopted Stormwater Drainage Control Standards.
         (d)   Warranty deed. A copy of the warranty deed showing ownership of property.
         (e)   Recorded plat. A copy of the recorded plat of the property, if applicable.
         (f)   Stormwater Pollution Prevention Plan (SWP3). The Stormwater Pollution Prevention Plan (SWP3) in accordance with the specifications identified in the currently adopted Stormwater Pollution Prevention and Erosion Control Standards.
         (g)   Small site notice (less than five acres). A copy of Arkansas Department of Environmental Quality’s (ADEQ) small site notice where construction on a site will disturb soil or remove vegetation on less than five acres during the life of the construction project.
         (h)   NOI (five or more acres). A copy of the Notice of Intent (NOI) submitted to ADEQ is required at the time of application where construction on a site will disturb soil or remove vegetation on five or more acres. The ADEQ approved National Pollutant Discharge Elimination System (NPDES) permit shall be submitted prior to approval of the grading permit.
      (4)   Review and approval.
         (a)   Evaluation. Grading plans shall be evaluated by the City Engineer for conformance with the requirements of all applicable regulations, including but not limited to, the currently adopted stormwater regulations as established by United State Environmental Protection Agency, Region VI published in the Federal Register; the city’s currently adopted Stormwater Pollution Prevention and Erosion Control Standards; and the city’s currently adopted Stormwater Drainage Control Standards.
         (b)   Variations in requirements. Requirements may be varied by the City Engineer with the approval of the Planning Commission. The extent to which variations may be made will depend on the soil types encountered, planned slopes, planned vegetation, and investigative engineering reports. In no case shall the City Engineer waive or modify any of the minimum erosion control requirements.
         (c)   Approval. No grading permit shall be issued until the grading plan, endorsed by a registered architect, landscape architect, engineer, or similar design professional, is approved in writing by the City Engineer.
         (d)   One-time approvals.
            1.   Utilities. Public and private utility organizations may obtain a one-time approval from the City Engineer for all routine underground electric, water, sewer, natural gas, telephone, or cable facilities. The approval will include a utility organization and its contractors, agents, or assigns and will be permanent in nature as long as the original approved procedures are followed.
            2.   Stockpiling materials. One-time approval may be obtained by public or private entities for the stockpiling of fill material, rock, sand, gravel, aggregate, or clay at particular locations, subject to the Zoning Code.
      (5)   Permit posted. A copy of the grading permit cover page shall be posted at or near the street right-of-way line and shall be clearly visible from the street.
   (E)   Retaining walls.
      (1)   Applicability. The requirements of this section shall apply to the construction, installation, extension and replacement of all retaining walls, as defined in § 152.015, of more than four feet in height, measured from the final grade at lower-side of wall to the top of the wall, in all zoning districts, except as exempted in (1), Exemptions below.
      (2)   Exemptions. Retaining walls that meet the following requirements shall be exempt from these requirements:
         (a)   Retaining walls less than four feet in height.
         (b)   Retaining walls designed as part of the primary structure.
         (c)   Retaining walls shown on an approved large scale development plan or preliminary plat.
         (d)   Retaining walls designed as part of a public capital improvement project.
      (3)   Permit required. A retaining wall permit shall be obtained prior to beginning construction, extension or replacement of all applicable retaining walls.
         (a)   Application. To obtain a retaining wall permit, a completed application form and a plot plan (site plan) must be submitted to the Community Development Office. The plot plan shall show:
            1.   Location of all property lines;
            2.   Location of all existing and proposed structures;
            3.   Location of existing retaining walls on or adjacent to the property that is to remain in place, if applicable;
            4.   Portions of existing retaining wall that will be replaced, if applicable;
            5.   Location of new retaining wall;
            6.   Location of utilities and utility easements; drainage easements and drainageways;
            7.   Construction details to include, but not limited to, dimensions, crosssection, and footing design;
            8.   Elevations above and below the retaining wall;
            9.   A note indicating the height of the proposed retaining wall and the material;
            10.   Engineer’s certification, if required; and
            11.   Additional information may be requested from staff after initial review.
         (b)   Review and approval. Once all the required information is submitted, it shall be reviewed by Community Development for compliance. If the application is approved, the applicant shall pay the permit fee and the retaining wall permit will be issued.
         (c)   Compliance. All retaining walls shall be installed in compliance with the retaining wall regulations and with the information shown on the approved plot plan and retaining wall permit application form.
         (d)   Inspection required. The applicant shall contact Building Inspections to request a final inspection upon completion of the retaining walls. If the building inspector determines that the retaining wall is constructed in accordance with the requirements of this chapter and the approved retaining wall permit, a certificate of compliance will be issued. If the retaining wall does not pass the inspection, the Building Inspector shall prepare an inspection report detailing the deficiencies.
      (4)   Engineer certification required. An engineer’s design, certification and construction observation shall be required in the instances listed below. All engineering services shall be performed under the supervision of a professional engineer registered in the State of Arkansas.
         (a)   Any retaining wall over four feet in height where one and one-half times the height of the wall is either:
            1.   Greater than or equal to the building setback of an adjacent lot, or
            2.   Such distance encroaches on any structure.
               Height of wall X 1.5 adjacent setback
 
         (b)   Any retaining walls over four feet in height located adjacent to a public right-of-way.
      (5)   Private property. All retaining walls shall be located on private property and shall be built with the consent of the property owner. The retaining wall installer and/or property owner shall be responsible to correctly locate property boundaries. Retaining walls shall not encroach neighboring property lines.
      (6)   Sight triangle. Retaining walls over 30 inches constructed near street intersections shall not be located in the “sight distance triangle,” shown below, in order to provide a reasonable degree of traffic visibility.
 
      (7)   Easements.
         (a)   Utility easements. Retaining walls shall not restrict access to utilities. Retaining walls proposed in a utility easement shall be approved on a case-by-case basis.
         (b)   Drainage easements. Retaining walls shall not impede the normal flow of storm water and shall not cross an open drainage channel. Retaining walls proposed in drainage easements shall be approved on a case-by-case basis.
         (c)   Access easement. Retaining walls shall not be constructed over a public or private access easement.
      (8)   Terraced retaining walls. If walls are terraced, the upper wall shall be located no closer to the lower wall than 1.0 times the height of the tallest wall.
         Height of largest wall x 1.0 = Distance between walls
 
   (F)   Slopes. Slopes of 1:1 or steeper shall be required to comply with the retaining wall regulations above.
   (G)   Construction and installation. The construction and installation of concrete segmental retaining wall systems shall comply with Concrete Segmental Retaining Walls System manufacturer’s specifications.
(Ord. 2013-04-417, passed 4-2-13; Am. Ord. 2013-09-440, § 152.1000.7, passed 9-3-13)