(A) No land shall be developed and no use shall be permitted that results in water run-off causing flooding or erosion on adjacent property. Run-off shall be properly channeled into a storm drain, watercourse, ponding area or other suitable facility.
(B) An approved drainage plan shall be submitted and approved for any new, redeveloped, or expanded commercial, industrial, multiple residential and institutional development, subject to the following requirements.
(1) A maximum storm water run-off coefficient of 0.6 for a five-year rainfall event (2.4 cubic feet per second per acre). When the development drains immediately into a stormwater trunk having a design capacity that can accommodate a run-off coefficient greater than 0.6, as determined by the City Engineer and in accordance with the adopted Apple Valley Master Stormwater Management Plan, the run-off coefficient of the drainage plan may be increased to no more than 0.9.
(2) On-site infiltration of the first one-half inch of storm water resulting from any rainfall event. The volume of infiltration necessary to achieve this standard is to be calculated with the formula: Volume of infiltration area (acres feet) = (0.042') x (number of acres). This requirement may be waived if the soil conditions are found to be unsuitable for infiltration or if the infiltration is already being accomplished within the drainage district (as identified within the adopted Apple Valley Master Stormwater Management Plan) in which the subject development property lies.
(C) The maximum impervious surface area on a lot or parcel with a one-family detached dwelling (house) or lots with two-family attached dwellings (twinhome) shall not exceed the following coverage:
Lot Size1 |
Maximum Impervious Coverage Allowed |
10,000 sq. ft. or greater | 35% |
9,999 sq. ft. - 7,500 sq. ft. | 40% |
7,499 sq. ft. - 6,000 sq. ft. | 45% |
Less than 6,000 sq. ft. | 50% |
(1) Actual lot area shall be rounded up to the nearest whole number for determination of its lot size hereunder.
(2) (a) Lots located within a "PD" (Planned Development) zoning district on which an one-family detached dwelling (house) or lots with two-family attached dwellings (twin home) is a permitted use shall comply with the requirements above, unless impervious surface coverage is specifically addressed in the ordinance establishing the PD zoning district.
(b) Lots zoned for multi-family dwellings on which the dwelling units, attached or detached, comprises the lot of record and the open space or yard surrounding the unit is not exclusively owned by the dwelling unit owner and is instead owned as a CIC or other common property interests, are not subject to this clause.
(D) The maximum impervious surface area allowed hereunder may be increased up to an additional 5% upon a showing of circumstances supporting good cause for additional impervious surface area in excess of the limitations herein and upon the installation of a city approved on-site stormwater management facility. An application for a request hereunder shall be filed with the City Clerk upon an application form furnished by the city. The application fee and a performance security escrow, which shall be in an amount established by City Council resolution, shall be paid and filed with the application.
(E) Any lot or parcel that has impervious surface area in excess of the maximum area allowed herein as of April 30, 2018, shall be deemed as legal nonconforming. The impervious surface area existing on a lot as of April 30, 2018, may be maintained, repaired or replaced, but may not be expanded. If the lot or parcel is redeveloped in its entirety, the impervious surface area restrictions set forth herein shall apply.
(‘81 Code, § A1-57) (Ord. 291, passed 4-21-83; Am. Ord. 760, passed 10-14-04; Ord. 1050, passed 10-11-18; Am. Ord. 1099, passed 8-26-21) Penalty, see § 155.999