(a)
It is hereby determined that:
(1)
Land development projects and associated increases in impervious
cover alter the hydrologic response of local watersheds and increase
stormwater run off rates and volumes, flooding, stream channel erosion,
and sediment transport and deposition.
(2)
Stormwater run off contributes to increased quantities of waterborne
pollutants.
(3)
Stormwater run off, soil erosion and nonpoint source pollution can
be controlled and minimized through the regulation of stormwater run
off from development sites.
(b)
The city establishes this set of water quality and quantity policies
applicable to all surface waters in the city to provide reasonable
guidance for the regulation of stormwater run off for the purpose
of protecting local water resources from degradation.
(c)
It is determined that the regulation of stormwater run off discharges
from land development projects and other construction activities in
order to control and minimize increases in stormwater run off rates
and volumes, soil erosion, stream channel erosion, and nonpoint source
pollution associated with stormwater run off is in the public interest
and will prevent threats to public health and safety.
(Ordinance 12-03 adopted 4/19/12)
The purpose of this division is to establish minimum stormwater
management requirements and controls to protect and safeguard the
general health, safety, and welfare of the public residing in watersheds
within the city. This division seeks to meet that purpose through
the following objectives:
(1)
To minimize increases in stormwater run off from any development
or redevelopment in order to reduce flooding, siltation and streambank
erosion and maintain the integrity of stream channels;
(2)
To minimize the total annual volume of surface water run off which
flows from any specific site during and following development or redevelopment
to not exceed the predevelopment hydrologic conditions to the maximum
extent practicable;
(3)
To accommodate new development and redevelopment projects in a manner
that protects public safety, groundwater and surface water quality
and aquatic living resources and their habitats;
(4)
To employ permanent nonstructural and structural best management
practices (BMP’s) to protect water quality thereby raising public
awareness to stormwater quality related issues;
(5)
To remove and/or treat stormwater pollutants prior to discharge to
ground and surface waters throughout the city;
(6)
To ensure the long-term operation and maintenance of all permanent
stormwater quality features; and
(7)
To reduce stormwater run off rates and volumes, soil erosion and
nonpoint source pollution, wherever possible, to the waters of the
state through stormwater management controls and to ensure that these
management controls are properly maintained and pose no threat to
the public.
(Ordinance 12-03 adopted 4/19/12)
This division shall be applicable to all land development or
redevelopment applications for both small and large construction activities,
as defined by the TCEQ, unless eligible for an exemption or granted
a waiver by the director.
(Ordinance 12-03 adopted 4/19/12)
(a)
The city may provide additional policy, criteria and information
including specifications and standards, for the proper implementation
of the requirements of this division and may provide such information
in the form of an erosion control manual.
(b)
The erosion control manual may be amended from time to time based
on improvements in engineering, science, monitoring and local maintenance
experience. Stormwater treatment practices that are designed and constructed
in accordance with these design criteria will be presumed to meet
the minimum water quality performance standards.
(Ordinance 12-03 adopted 4/19/12)
No owner or operator shall be issued any building, grading or
other land development permits that are required for land-disturbance
activities without first satisfying the requirements of this division
prior to commencement of the proposed activity.
(Ordinance 12-03 adopted 4/19/12)
(a)
All applicable land development sites shall be designed according
to the specific performance criteria outlined in the city erosion
control manual or in conformance with a plan designed by an engineer
licensed in the state, approved by the director.
(b)
Prior to design, applicants are required to consult with the director
to determine if they are subject to additional post-construction stormwater
design requirements.
(Ordinance 12-03 adopted 4/19/12)
All stormwater management practices shall be designed so that
the specific storm frequency storage volumes (e.g., water quality,
channel protection, ten-year, one-hundred-year) as identified in the
current drainage design manual are met, unless the director grants
a waiver or the owner is exempt from such requirements. If hydrologic
or topographic conditions warrant greater control than that provided
by the minimum control requirements, the director may impose any additional
requirements deemed necessary to control the volume, timing, and rate
of runoff.
(Ordinance 12-03 adopted 4/19/12)
(b)
Applicants shall consult the erosion control manual for guidance
on the factors that determine site design feasibility when selecting
a stormwater management practice.
(Ordinance 12-03 adopted 4/19/12)
All stormwater management practices shall be designed to convey
stormwater and allow for maximum removal of pollutants and reduction
in flow velocities, which shall include, but are not be limited to:
(1)
Use of structural and nonstructural best management practices (BMP’s)
and controls;
(2)
Maximizing of path flow distance from inflow points to outflow points;
(3)
Protection of inlet and outfall structures; and
(4)
Elimination of erosive flow velocities.
(Ordinance 12-03 adopted 4/19/12)
All stormwater management and/or treatment practices shall have
an enforceable operation and maintenance agreement to ensure the system
functions as designed. This agreement will include any and all maintenance
easements required to access and inspect the stormwater practices,
and to perform routine maintenance as necessary to ensure proper functioning
of the stormwater practice.
(Ordinance 12-03 adopted 4/19/12)
Owners are required by the city to implement structural measures
to reduce runoff volumes and velocities at sites where downstream
infrastructure is insufficient to accommodate developed flows. The
following methods shall be considered appropriate for consideration
as structural stormwater practices:
(1)
Swales and channels;
(2)
Culverts, inlets and pipes;
(3)
Detention;
(4)
Energy dissipaters;
(5)
Infiltration trenches;
(6)
Stormwater ponds;
(7)
Porous surfaces; and
(8)
Reuse (rain harvesting, etc.).
(Ordinance 12-03 adopted 4/19/12)
(a)
New and innovative technologies shall be evaluated and are encouraged
for use providing that there is sufficient documentation as to their
effectiveness and reliability.
(b)
Alternately, new structural stormwater practices will not be accepted
for inclusion in the city until independent performance data shows
that the structural control conforms to local and/or state criteria
for treatment, conveyance, maintenance and environmental impact.
(Ordinance 12-03 adopted 4/19/12)
(a)
Any area of land from which the natural vegetative cover has been
either partially or wholly cleared or removed by development activities
shall be revegetated within ten (10) calendar days from substantial
completion of such clearing and construction. The following criteria
shall apply to revegetation efforts:
(1)
Reseeding must be done with a perennial, nonwinter season cover crop
accompanied by placement of matting or its equivalent of sufficient
coverage to control erosion until such time as the cover crop is established
over ninety (90) percent of the seeded area.
(2)
Replanting with native woody and herbaceous vegetation must be accompanied
by placement of matting, mulch or an equivalent of sufficient coverage
to control erosion until the plantings are established and are capable
of controlling erosion.
(3)
Any area of revegetation must exhibit survival of a minimum of seventy
(70) percent of the cover crop throughout the year immediately following
revegetation. Revegetation must be repeated in successive years until
the minimum seventy (70) percent survival for one (1) year is achieved.
(b)
Upon instruction from the director, a landscaping plan prepared by
a state registered landscape architect shall be submitted with the
final design describing the vegetative stabilization and management
techniques to be used at a site after construction is completed. The
landscaping plan will explain not only how the site will be stabilized
after construction, but who will be responsible for the maintenance
of vegetation at the site and what practices will be employed to ensure
that adequate vegetative cover is preserved. The landscaping plan,
if required, must be approved by the director prior to land-disturbing
activities.
(Ordinance 12-03 adopted 4/19/12)
(a)
Stormwater system responsible party.
(1)
For privately owned stormwater drainage systems and/or water quality
devices used for residential or commercial areas, the developer shall
be responsible for all of the maintenance and repair of such stormwater
drainage systems and/or water quality devices serving that residential
or commercial area until the developer or owner no longer has an ownership
interest in any property served by the stormwater drainage system
and/or water quality device.
(2)
Once a homeowners’ association (HOA) is organized and becomes
active for a residential area served by a stormwater drainage system
and/or water quality device, the homeowners’ association shall
be responsible for the maintenance and repair of the stormwater drainage
system and/or water quality device. In the event there is no active
homeowners’ association or the homeowners’ association
fails to maintain the privately owned stormwater drainage system and/or
water quality device, then the city may, but is not required, to maintain
and repair the system and/or device.
(3)
Maintenance of a storm drainage system and/or water quality device
shall include such items, but not be limited to:
(A)
Mowing of tall weeds and grass;
(B)
Regular and routine removal of floatables and debris;
(C)
Dredging of silt and removal off site;
(D)
Correcting failures of inlet or outlet control structures;
(E)
Implementation of erosion mitigation measures;
(F)
Repair and maintenance of aeration equipment; and
(G)
Maintaining optimal operation of underground and above ground detention.
(b)
Disclosure of HOA information to the MS4.
(1)
Upon the organization and formation of a homeowners’ association,
the HOA should provide updated contact information to the city for
compliance and reporting communications. The minimum information to
be provided by the HOA to the city includes:
(A)
Name of subdivision and homeowners’ association;
(B)
Name, address, telephone number and email address of any management
company involved with activities related to the HOA (if applicable);
(C)
Name, address, telephone number and email address of a direct contact
person representing or authorized to act on behalf of the HOA;
(D)
Date of formation of the HOA;
(E)
Current listing of stormwater drainage structures and/or water quality
devices over which the homeowner’s association has control;
and
(F)
Dates when any changes were made to the HOA board, structure or the
storm drainage system and/or water quality device over which the HOA
has control.
(2)
Any changes to the contact information regarding the HOA must be
reported immediately to the city planning department.
(3)
The HOA is required to annually contact the city planning department
to ensure that all information is up to date.
(c)
Authorization to inspect, adopt and impose best management practices.
(1)
The city has the authority to conduct stormwater inspections to require
implementation of best management practices where appropriate.
(2)
The selection, application and maintenance of BMP’s must be
sufficient to prevent or reduce the likelihood of pollutants entering
the receiving storm drainage system.
(3)
The city may adopt and impose requirements identifying specific BMP’s
for any activity, operation or facility, which may cause a discharge
of pollutants to the storm drainage system. Where specific BMP’s
are required, every person undertaking such activity or operation
or owning or operating such facility shall implement and maintain
BMP’s at the person’s own expense.
(Ordinance 12-03 adopted 4/19/12)
