The director of public works/city engineer is hereby appointed
the floodplain administrator to administer and implement the provisions
of this article and other appropriate sections of 44 CFR (Emergency
Management and Assistance - National Flood Insurance Program Regulations)
pertaining to floodplain management.
Duties and responsibilities of the floodplain administrator
shall include, but not be limited to, the following:
(1)
Maintain and hold open for public inspection all records pertaining
to the provisions of this article.
(2)
Review permit application to determine whether to ensure that the
proposed building site project, including the placement of manufactured
homes, will be reasonably safe from flooding.
(3)
Review, approve or deny all applications for development permits
required by adoption of this article.
(4)
Review permits for proposed development to assure that all necessary
permits have been obtained from those federal, state or local governmental
agencies (including section 404 of the Federal Water Pollution Control
Act Amendments of 1972, 33 U.S.C. 1334) from which prior approval
is required.
(5)
Where interpretation is needed as to the exact location of the boundaries
of the areas of special flood hazards (for example, where there appears
to be a conflict between a mapped boundary and actual field conditions)
the floodplain administrator shall make the necessary interpretation.
(6)
Notify, in riverine situations, adjacent communities and the state
coordinating agency which is the Texas Water Development Board (TWDB)
and also the Texas Commission on Environmental Quality (TCEQ), prior
to any alteration or relocation of a watercourse, and submit evidence
of such notification to the FEMA (FEMA).
(7)
Assure that the flood carrying capacity within the altered or relocated
portion of any watercourse is maintained.
(8)
When base flood elevation data (BFE) has not been provided in accordance with section 22.07.007, the floodplain administrator shall obtain, review and reasonably utilize any BFE data and floodway data available from a federal, state or other source, in order to administer the provisions of division 3.
(9)
When a regulatory floodway has not been designated, the floodplain
administrator must require that no new construction, substantial improvements,
or other development (including fill) shall be permitted within zones
A1-30 and AE on the community’s FIRM, unless it is demonstrated
that the cumulative effect of the proposed development, when combined
with all other existing and anticipated development, will not increase
the water surface elevation of the base flood more than one foot at
any point within the community.
(10)
Under the provisions of 44 CFR chapter 1, section 65.12, of the National Flood Insurance Program regulations, a community may approve certain development in zones A1-30, AE, AH, on the community’s FIRM which increases the water surface elevation of the base flood by more than 1 foot, provided that the community first completes all of the provisions required by 44 CFR chapter 1, section 65.12.
(a)
No new construction is allowed in floodplain areas, but construction
is allowed in those areas that can be reclaimed from the floodplain.
The city uses a natural floodway in addition to the regulatory floodway
established by FEMA in managing the floodplains of the city. The natural
floodway consists of the natural channel and floodplain that is effective
in conveying the design flood. Areas of ineffective flow around bridges,
topographic constrictions and other constrictions are excluded from
the natural floodway. The effective flow area and limits of the natural
floodway are determined using four-to-one flow expansions downstream
of constrictions and one-to-one flow contractions upstream of constrictions.
Reclamation by filling in floodplain within areas of ineffective flow,
outside of the natural floodway, are not subject to the same requirements
as areas within the natural floodway. A development permit for floodplain
reclamation or alteration for all types of reclamation shall be allowed
only if all of the following criteria are met:
(1)
Alterations shall be in compliance with FEMA guidelines. A portion
of the 100-year floodplain may be reclaimed provided there is no upstream
or downstream increase in the water surface elevation and acceptable
velocities are maintained.
(2)
Any alteration of floodplain areas shall not cause any additional
expense in any current or projected public improvements.
(3)
Maximum slopes of filled areas or excavated areas not in rock shall
not exceed three to one (three horizontal to one vertical). Any city-maintained
land shall be at least on a four-to-one slope. Fill slopes, vertical
walls, terracing and other slope treatments may be considered, provided
that no unbalancing of stream flow results.
(4)
Alterations of the floodplain or natural floodway are permitted without
consideration to the water surface elevations when the entire floodplain
is on one’s own property. No significant rise in water surface
elevations of the design flood of the creek is permitted on adjacent
properties without the owner’s written consent.
(5)
Alterations of the floodplain shall not create an erosive water velocity
on or off site.
(6)
Alterations of the floodplain shall not increase downstream discharges
greater than an amount which would cause a significant increase in
the water surface elevations of the design flood of the creek.
(7)
The effects of existing improvements, or public and private improvements
for which a future commitment has been made by the city or county,
state or federal agencies, shall be used in determining water surface
elevations and velocities.
(8)
The floodplain shall be altered only to the extent permitted by equal
conveyance on both sides of the natural channel. The right of equal
conveyance applies to all owners and uses, including greenbelt, park
areas and recreational usages. Owners may relinquish their right to
equal conveyance by providing a written agreement to the city.
(9)
When constructing a swale parallel to the main channel, the elevation
of excavated areas in the floodplain shall not be lower than the lower
of either one-third of the depth of the natural channel, as measured
from the adjacent stream-bank, or the water surface elevation resulting
from the one-year flood. The upstream end of the excavation area shall
not tie into the creek, and no excavation shall be closer than 50
feet to the bank of the natural channel, except as necessary to drain.
Excavation of lakes may exceed the depth indicated above.
(10)
Relocation or alteration of the natural channel of streams with a
contributing drainage area of 320 acres or more shall not be permitted
without an environmental impact statement.
(b)
These criteria shall be met before a development permit can be issued
for a proposed project. Typical projects requiring a development permit
include placing fill, whether or not it actually raises the property
out of the floodplain; constructing a dam; straightening channel sections;
temporary storage of fill materials, supplies and equipment; creating
on- or off-line lakes; installing retaining walls or other creek side-slope
protection; changing the streambed gradient; constructing a swale
parallel to the main channel and making improvements, substantial
or otherwise, to existing structures in a floodplain in which the
existing outside dimensions of the structure are increased.
(c)
The required submittals for a development permit are listed. In general,
the information needed for the application of projects involving floodplain
areas may be obtained by running a backwater model, such as HEC-2;
and a flood routing model, such as TR-20 or HEC-1. The backwater information
shall be used to determine that upstream water surface elevations
and erosive velocities have not increased. Flood-routing information
shall be used to ensure that the cumulative effects of the reduction
in floodplain storage of floodwaters will not cause downstream increases
in water surface elevations and erosive velocities.
(d)
Applicants can obtain copies of the existing conditions backwater
and models and flood-routing where available from the director of
public works. These models shall be kept current with modification
to the floodplains.
(a)
Prior to final acceptance by the city of utilities and street construction
for projects involving floodplain alterations or adjacent to defined
floodplains, creeks, channels and drainage ways, a certified statement
shall be prepared by a registered public surveyor, showing that all
lot elevations, as developed within the subject project, meet or exceed
the required minimum finished floor elevations shown on the final
plat of the subdivision. This certification shall be filed with the
director of public works.
(b)
In addition, at any time in the future when a building permit is
desired for existing platted property which is subject to flooding
or carries a specified or recorded minimum finished flood elevation,
a registered public surveyor or a registered professional engineer
shall prepare a certified statement that sites are built to the design
elevations. The certified survey data showing the property to be at
or above the specified elevation shall be furnished to the director
of public works for approval. A certificate of compliance with the
provisions of this article, pertaining to specified finished floor
elevations, shall be required.
(c)
The applicants shall furnish, at their expense, to the director of
public works the above certifications and any other certified engineering
and surveying information requested by the director of public works
to confirm that the required minimum floor and pad elevations have
been achieved. Building permits will not be issued until:
(1)
Conditional letter of map revision or amendment has been issued by
FEMA; and
(2)
Lots and/or sites certified by a registered public surveyor or a
registered professional engineer that they are elevated from the floodplain
according to FEMA-approved revisions to the floodplain and the requirements
of this article.
(a)
Application for a floodplain development permit shall be presented
to the floodplain administrator on forms furnished by him/her and
may include, but not be limited to, plans in duplicate drawn to scale
showing the location, dimensions, and elevation of proposed landscape
alterations, existing and proposed structures, including the placement
of manufactured homes, and the location of the foregoing in relation
to areas of special flood hazard. Additionally, the following information
is required:
(1)
Elevation (in relation to mean sea level), of the lowest floor (including
basement) of all new and substantially improved structures;
(2)
Elevation in relation to mean sea level to which any nonresidential
structure shall be floodproofed;
(3)
A certificate from a registered professional engineer or architect that the nonresidential floodproofed structure shall meet the floodproofing criteria of section 22.07.062(2);
(4)
Description of the extent to which any watercourse or natural drainage
will be altered or relocated as a result of proposed development;
(5)
Maintain a record of all such information in accordance with section 22.07.032(1);
(b)
Approval or denial of a floodplain development permit by the floodplain
administrator shall be based on all of the provisions of this article
and the following relevant factors:
(1)
The danger to life and property due to flooding or erosion damage;
(2)
The susceptibility of the proposed facility and its contents to flood
damage and the effect of such damage on the individual owner;
(3)
The danger that materials may be swept onto other lands to the injury
of others;
(4)
The compatibility of the proposed use with existing and anticipated
development;
(5)
The safety of access to the property in times of flood for ordinary
and emergency vehicles;
(6)
The costs of providing governmental services during and after flood
conditions including maintenance and repair of streets and bridges,
and public utilities and facilities such as sewer, gas, electrical
and water systems;
(7)
The expected heights, velocity, duration, rate of rise and sediment
transport of the floodwaters and the effects of wave action, if applicable,
expected at the site;
(8)
The necessity to the facility of a waterfront location, where applicable;
(9)
The availability of alternative locations, not subject to flooding
or erosion damage, for the proposed use.
(a)
The appeal board, as established by the community, shall hear and
render judgment on requests for variances from the requirements of
this article.
(b)
The appeal board shall hear and render judgment on an appeal only
when it is alleged there is an error in any requirement, decision,
or determination made by the floodplain administrator in the enforcement
or administration of this article.
(c)
Any person or persons aggrieved by the decision of the appeal board
may appeal such decision in the courts of competent jurisdiction.
(d)
The floodplain administrator shall maintain a record of all actions
involving an appeal and shall report variances to the FEMA upon request.
(e)
Variances may be issued for the reconstruction, rehabilitation or
restoration of structures listed on the National Register of Historic
Places or the state inventory of historic places, without regard to
the procedures set forth in the remainder of this article.
(f)
Variances may be issued for new construction and substantial improvements to be erected on a lot of 1/2 acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing the relevant factors in section 22.07.035(b) of this division have been fully considered. As the lot size increases beyond the 1/2 acre, the technical justification required for issuing the variance increases.
(g)
Upon consideration of the factors noted above and the intent of this article, the appeal board may attach such conditions to the granting of variances as it deems necessary to further the purpose and objectives of this article (section 22.07.003).
(h)
Variances shall not be issued within any designated floodway if any
increase in flood levels during the base flood discharge would result.
(i)
Variances may be issued for the repair or rehabilitation of historic
structures upon a determination that the proposed repair or rehabilitation
will not preclude the structure’s continued designation as a
historic structure and the variance is the minimum necessary to preserve
the historic character and design of the structure.
(j)
Prerequisites for granting variances:
(1)
Variances shall only be issued upon a determination that the variance
is the minimum necessary, considering the flood hazard, to afford
relief.
(2)
Variances shall only be issued upon:
(A)
Showing a good and sufficient cause;
(B)
A determination that failure to grant the variance would result in
exceptional hardship to the applicant; and
(C)
A determination that the granting of a variance will not result in
increased flood heights, additional threats to public safety, extraordinary
public expense, create nuisances, cause fraud on or victimization
of the public, or conflict with existing local laws or ordinances.
(3)
Any application to which a variance is granted shall be given written
notice that the structure will be permitted to be built with the lowest
floor elevation below the BFE, and that the cost of flood insurance
will be commensurate with the increased risk resulting from the reduced
lowest floor elevation.
(k)
Variances may be issued by a community for new construction and substantial
improvements and for other development necessary for the conduct of
a functionally dependent use provided that:
