(A) The parcel drainage shall be designed to flow away from the top of the foundation. Storm water being directed to the side yard of the parcel shall be directed into a formed drainage swale, having a minimum slope of one percent and a maximum slope of seven percent. In the event that conditions dictate that some parts of the lot be higher than the structure foundation, the grading plan must show specific drainage configurations for the parcel specifying that all drainage is to be directed to flow away from the foundation in an acceptable manner.
(B) Rear lot line swales shall be graded to a positive outlet or inlet structure at a minimum flowline slope of 1.5% and shall have side slopes of (horizontal to vertical) or less.
(C) Construction and work such as walkways, driveways, landscaping or any structure shall be installed so that the construction of 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.
(D) The flow from offsite 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 must be designed in such a way to adequately convey the flow of all surface water for a 100-year storm frequency without damage to adjoining structures.
(E) All overflow routes for the 100-year storm and for accumulated storm water runoff from several lots or from offsite 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.
(Ord. 808, passed 4-19-2006)