(a) It shall
be unlawful and an offense for any person or entity to do work or
cause work to be accomplished that diverts, impounds, or otherwise
alters the natural flow of surface water drainage in such a manner
that prevents natural drainage across an existing property, increases
runoff to adjacent properties, causes damage to property, creates
an attractive nuisance, or causes an unreasonable risk to the public
health, safety, or general welfare.
(b) Any proposed project which may affect the adopted floodplain or floodway must meet all requirements as identified in chapter
7 flood damage, prevention and control.
(Ordinance 1860 adopted 4/12/2010)
(a) No person,
firm, or corporation shall do, cause or permit to be done, the alteration
of property to prevent existing drainage run-off, or patterns from
entering the property in the natural course of drainage.
(b) No person,
firm, or corporation shall do, cause or permit to be done, the installation,
modification, or relocation of any construction improvement where
the improvement, when completed, will impact other property. The other
property may be either upstream or downstream from the property on
which the improvement is to be made. The impact is primarily related
to flooding of a building structure. No permit shall be issued where
engineering data from a qualified professional engineer or the opinion
of the city reveals that such improvement would worsen any known drainage
or flooding problem.
(c) Any
person or entity applying for a permit which alters natural grade
through coverage, fill, or excavation shall be required to meet the
requirements within this section. In order to provide adequate drainage
away from foundations as well as minimize run-off rate to adjacent
properties, the following standards shall apply to all properties
which propose alteration of grade whether by an increase to structural
footprint or roof cover, an increase in impervious surface coverage,
or any work which alters existing grade conditions. No increase of
rate flow shall be permitted onto adjacent properties.
(1) The
slope of any altered final grading of soils around the foundation
of any structure or improvement shall not be less than five (5) percent
when measured from grade to any point ten (10) feet from grade elevation
at the foundation wall of the structure.
a. Exception:
Existing natural grades less than five (5) percent may be maintained.
(2) Diversion
of surface water shall be contained within the limits of the owner's
contiguous property, shall be conveyed by a free, positive, and uninterrupted
means, and shall be designated as the following:
(3) All
site plans submitted for projects where natural grade is altered,
or covered must indicate the following:
a. Drainage
type as listed above,
b. Drainage
flow arrows indicating direction of proposed runoff, and
c. All
proposed berms, swales, or drains.
(4) A
storm water management and drainage plan (SDP) shall be required for
the following projects:
a. New
single-family residential, commercial, multi-family residential, industrial,
institutional, utility developments, or any new developments including
additions when the proposed property being developed exceeds five
(5) percent slope from property line to property line, and
b. Propose
an increase in lot coverage greater than twenty-five (25) percent
above existing lot coverage, and
c. Propose
an increase in the total impervious surface on a property by twenty-five
(25) percent of the existing impervious surface coverage.
(5) The
director shall require a storm water management and drainage plan
(SDP), designed and sealed by a registered professional engineer,
which demonstrates that a proposed construction plan or recently permitted
construction meets all of the provisions of this article and does
not increase the rate or direction of flow of run-off from an existing
property and does not prevent natural drainage from entering an existing
property.
(6) The
director's office shall review each SDP to verify whether an increase
in the rate or direction of flow of run-off from an existing property
is created by the proposed project or whether the proposed project
prevents natural drainage. In cases where prevention or an increase
is determined, the city reserves the right to submit the SDP to the
city's engineer for additional review. Any outside review is subject
to fees according to the adopted schedule of development fees.
(7) If
irregular site topography, use of landscaping, or architectural features
such as raised planting beds, retaining walls, fences, or sidewalks
prevent compliance with provisions of this section, the designer shall
provide alternate methods and means as may be approved by the director
to assure that the requirements of this Code are met. The drainage
plan must be submitted, reviewed, and approved prior to issuance of
a permit and the work must be approved prior to final inspection and
occupancy of the structure.
(Ordinance 1860 adopted 4/12/2010)