a. The owner or developer of property to be developed shall be responsible for all storm drainage flowing on his property. This responsibility includes the drainage directed to that property by prior development as well as drainage naturally flowing through the property by reason of topography.
b. Adequate consideration shall be given by the owner in the development of property to determine how the discharge leaving the proposed development will affect downstream property.
c. In all new development where stormwater runoff has been collected or concentrated, it shall not be permitted to drain onto adjacent property except in existing creeks, channels or storm sewer unless proper drainage easements or notarized letters of permission from the affected property owners are provided.
d. The subdivider shall pay for the cost of all drainage improvements required for the development of his subdivision, including any necessary off-site channels or storm sewers and acquisition of the required easements with the following exception: If the owner is unable to acquire the necessary off-site easements, he shall provide the City with documentation of his efforts, including evidence of a reasonable offer made to the affected property owners. Should the City receive such a written request for assistance and the City determines that the need for off-site easements is the only practical solution to the problem, the City shall attempt to acquire these easements through negotiations and, if necessary, condemnation. It shall be understood that condemnation shall only be used as a condition of last resort. In any case, the owner or developer shall pay all costs associated with the acquisition of these easements.
Where it is anticipated that additional runoff incident to the development of the subdivision will overload an existing downstream drainage facility, whether natural or man-made, and result in hazardous conditions, the P&Z may withhold approval of the subdivision until appropriate provision has been made to accommodate the problem, and plans shall be provided which include all necessary off-site improvements including storm systems, channel grading, driveway adjustments, culvert improvements, etc.