(a) A grading permit will be required and shall necessitate the submission of grading plans. The grading plans must be approved by the Village, and a grading permit issued by the Village, before the following activities can commence:
(1) Construction of a new structure in a subdivision or planned unit development where an overall grading plan has been approved by the corporate authorities or a parcel is subject to such overall grading plan.
(2) Construction of a new structure in an established subdivision or planned unit development that does not have an approved overall grading plan.
(3) The movement of a structure from a parcel of land that affects such parcel, or the parcel to which it is being moved.
(4) Any filling or excavation on a parcel of land that affects such parcel or any other parcel.
(5) The damming, altering, obstructing or changing of natural terrain or a waterway or watercourse carrying natural drainage from upstream property.
(6) Any change to an existing structure, including additions or alterations to an existing structure that could affect storm water drainage to the parcel being improved or to the adjoining property, as determined by the Building Commissioner.
(b) Any grading plan submitted pursuant to the requirements of this chapter shall contain the following information and be consistent with the following requirements:
(1) Foundation elevation, including the top of the foundation and any openings below the top of the foundation, on all new or existing structures or portions thereof, shall be shown.
(2) Site drainage shall be indicated, showing existing and proposed grades for a particular parcel, and for adjoining properties affected, with a minimum of one-foot contour intervals, in sufficient detail to clearly indicate drainage flows.
(3) The parcel drainage shall be designed to flow away from the top of the foundations. Storm water being directed to the side yard of the parcel shall be directed into a formed drainage swale, having a minimum slope of two percent and a maximum slope of ten percent. The side slopes of any drainage swale shall not exceed a 3:1 slope. Bank stabilization will be required if deemed necessary by the Village Engineer.
In the event that conditions dictate that some parts of the lot be higher than the structure foundation, the grading must show specific drainage configurations for the parcel, specifying that all drainage is to be directed to flow away from the foundation.
Notwithstanding the foregoing drainage swale slope and side slope requirements, the Village Engineer shall have the authority to approve a drainage swale slope and/or slide slope, that is not in compliance with the foregoing requirements, in the event that the site conditions do not allow for compliance with said requirements.
(4) Construction and work, such as walkways, driveways, landscaping or any structure, shall be installed so that construction of the same will not interfere with drainage. All sidewalks, driveways, patios and other flat work shall be at an elevation relative to the foundation wall, so that water will drain away from the structure on all sides and off the lot in a manner which will provide reasonable freedom from erosion and permanently pocketed surface water.
(5) The flow from off-site tributary areas that are tributary to an intermittent stream or overflow route that must pass through the parcel must be identified on the grading plan, and a conveyance system must be designed in such a way to adequately handle the flow of all water to accommodate a 100-year storm frequency.
(6) All overflow routes for the 100-year storm and for accumulated storm water runoff from several lots, or from off-site catchment areas, must be clearly designated on the grading plan with the total width of the flow route contained within an easement for drainage purposes.
(7) Evidence must be given to document that the flow leaving the developed parcel does not adversely affect the downstream system. If the existing receiving system is inadequate to handle the 100-year flow as calculated, detention will be required to ensure that the release from the improved parcel does not cause downstream flooding.
(8) If applicable, all wetland boundaries must be shown, and a construction permit from the Army Corps of Engineers acquired, prior to Village approval.
(9) If applicable, all floodplain and floodway boundaries must be shown, and all applicable standards met, for construction in these areas, including, but not limited to, any necessary permits required by Chapter 1462 of this Code, prior to Village approval.
(c) All storm water management facilities within any development must be constructed in accordance with the plans provided by the permittee's design engineer and approved by the Village Engineer. The design drawings must be certified by a registered professional engineer, and provided on standard twenty-four inch by thirty-six inch sheets. Smaller individual parcels may be submitted on a smaller appropriate size.
(Ord. 1991-53. Passed 10-28-91; Ord. 2019-24. Passed 10-14-19; Ord. 2019-28. Passed 10-28-19.)