0605 ORDINANCE NO. t 6
AN ORDINANCE ADOPTING A STORM DRAINAGE POLICY FOR THE
CITY OF SOUTHLAKE, TEXAS; PROVIDING FOR THE SUBMISSION
OF PRELIMINARY AND FINAL DRAINAGE STUDIES; PROVIDING
DRAINAGE DESIGN CRITERIA; PROVIDING FOR THE DESIGN,
CONSTRUCTION AND MAINTENANCE OF ON -SITE AND OFF -SITE
DRAINAGE CHANNELS AND OTHER DRAINAGE IMPROVEMENTS;
PROVIDING FOR COST PARTICIPATION FOR OFF -SITE DRAINAGE
IMPROVEMENTS; PROVIDING REQUIREMENTS FOR RETENTION
AND DETENTION PONDS; PROVIDING FOR THE MAINTENANCE OF
DRAINAGE WAYS AND DRAINAGE EASEMENTS; PROVIDING FOR
VARIATIONS TO THIS ORDINANCE; PROVIDING FOR THE REPEAL
OF ORDINANCE NO. 482; PROVIDING THAT THIS ORDINANCE
SHALL BE CUMULATIVE OF ALL ORDINANCES; PROVIDING A
SEVERABILITY CLAUSE; PROVIDING A PENALTY FOR VIOLATIONS
HEREOF; PROVIDING A SAVINGS CLAUSE; PROVIDING FOR
PUBLICATION IN THE OFFICIAL NEWSPAPER; PROVIDING FOR
PUBLICATION IN PAMPHLET FORM; AND PROVIDING AN
EFFECTIVE DATE.
WHEREAS, the City of Southlake, Texas is a home rule city acting under its
charter adopted by the electorate pursuant to Article XI, Section 5 of the Texas
Constitution and Chapter 9 of the Local Government Code; and
WHEREAS, the City Council of the City of Southlake has determined that adequate
drainage regulations are necessary to protect the citizens of Southlake and the public in
general from storm water hazards resulting from the development of properties in the city
limits and the extraterritorial jurisdiction of the city; and
WHEREAS, the City Council heretofore adopted Ordinance No. 482 providing for
drainage regulations designed to protect the public health, safety and welfare; and
WHEREAS, after review, the City Council has determined that said minimum
regulations applicable to drainage within the city and the extraterritorial jurisdiction of the
city should be revised and updated as provided herein.
f:\files \muni \slake \ordinanc \drainage (12- 06 -93)
NOW, THEREFORE, BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY
OF SOUTHLAKE, TEXAS:
SECTION 1.
There is hereby adopted a Storm Drainage Policy for the City of Southlake as
provided in Exhibit "A" attached hereto and incorporated herein for all purposes. The
Storm Drainage Policy adopted herein shall have the force and effect of law.
SECTION 2.
This ordinance shall be cumulative of all provisions of ordinances of the City of
Southlake, Texas, except where the provisions of this ordinance are in direct conflict with
the provisions of such ordinances, in which event the conflicting provisions of such
ordinances are hereby repealed. Ordinance No. 482 is hereby repealed.
SECTION 3.
It is hereby declared to be the intention of the City Council that the phrases,
clauses, sentences, paragraphs and sections of this ordinance are severable, and if any
phrase, clause, sentence, paragraph or section of this ordinance shall be declared
unconstitutional by the valid judgment or decree of any court of competent jurisdiction,
such unconstitutionality shall not affect any of the remaining phrases, clauses, sentences,
paragraphs and sections of this ordinance, since the same would have been enacted by the
City Council without the incorporation in this ordinance of any such unconstitutional
phrase, clause, sentence, paragraph or section.
f: \files \muni \slake \ordinanc \drainage (12- 06 -93) 2
SECTION 4.
Any person, firm or corporation who violates, disobeys, omits, neglects or refuses
to comply with or who resists the enforcement of any of the provisions of this ordinance
or the Storm Drainage Policy adopted herein shall be fined not more than Five Hundred
Dollars ($500.00) for each offense. Each day that a violation is permitted to exist shall
constitute a separate offense.
SECTION 5.
All rights and remedies of the City of Southlake are expressly saved as to any and
all violations of the provisions of Ordinance No. 482 or any other ordinances affecting
drainage or flooding which have accrued at the time of the effective date of this ordinance;
and, as to such accrued violations and all pending litigation, both civil and criminal,
whether pending in court or not, under such ordinances, same shall not be affected by this
ordinance but may be prosecuted until final disposition by the courts.
SECTION 6.
The City Secretary of the City of Southlake is hereby authorized to publish the
Storm Drainage Policy in book or pamphlet form for general distribution among the public,
and the operative provisions of this ordinance as so published shall be admissible in
evidence in all courts without further proof than the production thereof.
SECTION 7.
The City Secretary of the City of Southlake is hereby directed to publish the
proposed ordinance or its caption and penalty together with a notice setting out the time
f:\ files \muni \slake \ordinanc \drainage (12- 06-93) 3
and place for a public hearing thereon at least ten (10) days before the second reading
of this ordinance, and if this ordinance provides for the imposition of any penalty, fine or
forfeiture for any violation of any of its provisions, then the City Secretary shall additionally
publish this ordinance or its caption and penalty in the official City newspaper one time
within ten days after passage of this ordinance, as required by Section 3.13 of the Charter
of the City of Southlake.
SECTION 8.
This ordinance shall be in full force and effect from and after its passage and
publication as required by law, and it is so ordained.
PASSED AND APPROVED ON FIRST READING ON THIS 7 DAY OF
199. .
--9141-- Il —1.
�J . -“< - s AYOR
A ST:
k, .1 * * CITY SECRETARY aettorti...2
PASSED AND APPROVED ON SECOND READING ON THIS Ai DAY OF
( ? ) (140 ,199: I
N �uu� 'qv
����a J , <N A KE, p ■ AYOR
s S 0
It >. ATT ST: I.
VZ..7 Xatile/
it
CI Y SECRETARY
,� �anu NNp
f:\ files \muni \slake \ordinanc \drainage (12- 06 -93) 4
APPROVED AS TO FORM AND LEGALITY:
.4
City Attorney
Date: Se
ADOP D: /1 I /L
EFFECTIVE: 0 i ° I
f: \files \muni \slake \ordinanc \drainage (12- 06 -93) 5
STORM DRAINAGE POLICY
Exhibit "A"
STORM DRAINAGE POLICY
Table of Contents
Page
Article 1 GENERAL PROVISIONS
1.01 Purposes 1 -1
1.02 Definitions 1 -1
Article 2 DRAINAGE STUDIES
2.01 General 2 -1
2.02 Preliminary Drainage Study 2 -1
A. When Required 2 -1
B. Qualification to Prepare Study 2 -1
C. Requirements 2 -1
D. Exemptions 2 -2
2.03 Final Drainage Study 2 -2
A. When Required 2 -2
B. Qualification to Prepare Study 2 -2
C. Requirements 2 -2
D. Exemptions 2 -2
2.04 Computer Models 2 -2
A. General 2 -2
B. HEC I Analysis 2 -2
C. HEC II Analysis 2 -2
Article 3 DRAINAGE DESIGN CRITERIA
3.01 Drainage Manual Reference 3 -1
A. Fort Worth Drainage Manual 3 -1
B. Highway Department Hydraulic Manual . . . 3 -1
C. Retention / Detention 3 -1
3.02 Design Storm Frequency 3 -1
A. R.O.W. / Easement Capacity 3 -1
B. Street Capacity 3 -1
1. Arterial Streets 3 -1
2. Collector Streets 3 -1
C. Storm Sewer Capacity 3 -2
D. Open Channels 3 -2
E. Culverts and Bridges 3 -2
3.03 Time of Concentration 3 -2
A. Average Conditions 3 -2
B. Unusual Circumstances 3 -3
3.04 Land Use Runoff Coefficients 3 -3
A. Fully Developed Criteria 3 -3
B. Land Uses 3 -3
C. Overdeveloped Tracts 3 -3
3.05 Miscellaneous Design Criteria 3 -3
A. Pipe Design Criteria 3 -3
2
1. Minimum Pipe Size 3 -3
2. Minimum Velocity 3 -3
3. Changes in Pipe Size 3 -4
4. Vertical and Horizontal Curves . . . 3 -4
B. Manhole Requirements 3 -4
C. Street Crowns 3 -4
D. Culverts 3 -4
1. End Sections 3 -4
2. Private Property 3 -4
E. Lakes 3 -4
F. Easements 3 -5
1. Outfall Extension 3 -5
2. Open Channel Easements 3 -5
3. Maintenance Access 3 -5
4. Detention / Retention Ponds 3 -6
G. Diversion or Impoundment 3 -6
Article 4 OPEN CHANNEL POLICY
4.01 General 4 -1
A. Channel Types 4 -1
B. Building Line Limitations 4 -1
C. Easement Widths 4 -1
4.02 Natural Channels 4 -1
A. With No Improvements 4 -1
B. Erosion Control 4 -1
1. Erosion Control 4 -1
4.03 Earth Channels 4 -1
A. General 4 -1
B. Soil Tests 4 -2
C. Channel Shape 4 -2
D. Pilot Channel 4 -2
E. Slope Treatment 4 -2
4.04 Concrete Lined Channels 4 -2
A. Channel Shape 4 -2
B. Curves or Deflections 4 -3
Article 5 ON -SITE IMPROVEMENTS
5.01 Owner's Responsibility 5 -1
A. Upstream Drainage 5 -1
B. Installation Costs 5 -1
C. Construction Plans 5 -1
D. Maintenance Bonds 5 -1
Article 6 OFF -SITE IMPROVEMENTS
6.01 General 6 -1
6.02 Limits of Off -Site Study 6 -1
A. Master Drainage Plan 6 -1
B. Limits of Study 6 -1
3
6.03 Responsibility for Off -Site Study 6 -1
A. First Development 6 -1
B. Credit for Cost of Study 6 -1
6.04 Requirements of Off -Site Study 6 -1
A. Complete Watershed 6 -1
B. Accuracy Level 6 -1
C. Cost Determination 6 -2
6.05 Off -Site Easement Acquisition 6 -2
6.06 Cost Participation for Off -Site Improvements . 6 -3
A. Adjacent Downstream Structures 6 -3
B. Other Downstream Improvements 6 -3
6.07 Construction of Off -Site Improvements 6 -4
A. Remaining Capacity in Critical Structure . 6 -4
B. No Capacity Remaining 6 -4
1. Prior Contributions 6 -4
2. Future Refunding 6 -4
Article 7 DRAINAGE STUDY REVIEW PROCESS
7.01 Submittal 7 -1
A. Coordination of Processing 7 -1
B. Fees 7 -1
C. Reproductions 7 -1
7.02 Responsibility for Review 7 -1
A. Director of Public Works 7 -1
B. City Engineer 7 -1
C. Approval 7 -1
D. Appeals 7 -1
7.03 Impact on Subdivision Approval 7 -2
A. Downstream Hazards 7 -2
Article 8 RETENTION AND DETENTION POLICY
8.01 General 8 -1
A. Intent 8 -1
B. Scale of Review 8 -1
1. Development Scale 8 -1
2. Site - specific Scale 8 -1
8.02 Development Scale Projects 8 -1
A. Review Process 8 -1
B. When Required 8 -1
C. Solutions 8 -1
1. Check Dams 8 -2
2. Detention Ponds 8 -2
3. Retention Ponds 8 -2
4
8.03 Site - Specific Scale 8 -2
A. Review Process 8 -2
B. When Required 8 -2
1. Overdeveloped Runoff 8 -2
2. Change in Use 8 -2
C. Solutions 8 -2
1. Parking Lot Storage 8 -3
2. Rooftop Storage 8 -3
3. On -Site Detention Ponds 8 -3
Article 9 MISCELLANEOUS PROVISIONS
9.01 Contingent Warning 9 -1
9.02 Maintenance of Drainageways & Drainage Facilities 9 -1
A. Natural Drainageways 9 -1
B. Drainage Easements with Surface Structures 9 -1
C. Failure to Maintain 9 -1
9.03 Compliance with other laws 9 -3
9.04 Enforcement 9 -3
A. Development Permit 9 -3
B. Building Permit 9 -3
C. Final Plat Filing 9 -3
9.05 Modifications and Variations 9 -4
A. Compliance 9 -4
B. Discretion of Council 9 -4
9.06 Liability Disclaimer 9 -4
A. General 9 -4
B. Professional Liability 9 -4
9.07 Injunctions 9 -4
5
ARTICLE 1
GENERAL PROVISIONS
Section 1.01 Purpose
The purpose of this ordinance is to provide for the orderly, safe
and healthful development of land both within the City and within
it's extraterritorial jurisdiction and to promote the health,
safety and general welfare of the community, and to minimize public
and private losses due to flood conditions. In order to carry out
the purpose hereinabove stated, it is hereby declared to be the
policy of the City to guide and regulate the implementation of all
drainage improvements both within the City and within it's
extraterritorial jurisdiction. This ordinance shall be
administered using the following guidelines:
A. Due consideration shall be given to the City's Master Plan,
Thoroughfare Plan, Land -Use Plan and other developmental
guides adopted by the City.
B. Consideration shall be given to both currently developed
property and anticipated development of property in the
future.
C. Protection of the soils, topography, wildlife, vegetation and
other amenities of the City shall be considered an objective
of this ordinance.
D. Determination of reasonable cost participation in any
improvements shall be reasonable and shall be consistently
applied to all developments or assessment programs.
Section 1.02 Definitions
A. General Rules: For the purpose of this ordinance, the
following rules shall be applied in constructing,
interpreting, or otherwise defining the terms and provisions
hereof:
1. Words used in the present tense shall include the future,
words used in the singular number shall include the
plural number and words used in the plural number shall
include the singular number.
2. The word "shall" is mandatory and the word "may" is per-
missive.
3. The phrase "used for" shall include the phrases,
1 - 1
"arranged for ", "designed for ", "intended for ", and
"occupied for ", and shall apply exclusively to physical
uses.
B. Definitions: For the purpose of this ordinance, certain words
or terms applicable hereto are defined as hereinafter
provided. Words and terms used in this ordinance, but not
defined in this ordinance shall have the meanings ascribed
thereto in the Zoning Ordinance, the Subdivision Ordinance, or
other applicable ordinances of the City.
Basin: The entire area of land which drains into a particular
design point via natural flow or manmade improvements. Sometimes
also referred to as watershed.
Benchmark: An elevation reference mark.
"CA" Factor: A multiplicative coefficient achieved by multiplying
the coefficient of runoff "C ", by the area in acres "A" that is
tributary to the point of design.
"cfs ": Cubic feet per second. A measure of the volume of water.
Critical Structures: An integral and readily identifiable part of
a drainage system, without which the efficiency of the drainage
system is compromised.
Detention: The detention of stormwater on a site or within a
project shall be interpreted as a temporary restrainment of runoff
with anticipation of normal runoff over an extended period of time.
Development: Any man -made change to improved or unimproved real
estate, including but not limited to, buildings or other struc-
tures, mining, dredging, filling, grading, paving, excavation or
drilling operations.
Development Permit: A permit required before development shall
begin in an area designated as within the limits of the base flood.
Drainage Easement: A delineated portion of land set aside for the
overland or underground transfer of storm water. This area shall
not have any permanent structures, fences, or other obstacles
hindering the safe transfer of water through the easement.
Drainage Improvements: All elements of a storm drainage system
consisting of streets, alleys, storm sewers, channels, culverts,
bridges, swales, and any other facility through which or over which
storm water flows.
FEMA: Abbreviation for "Federal Emergency Management Agency"
1 - 2
"FIRM Map ": A map produced by the U.S. Department of Housing and
Urban Development, which has the purpose of a Flood Insurance Rate
Map and on which the Federal Emergency Management Agency has
delineated both the areas of special flood hazards and the risk
premium zones applicable to the community.
Flood: A general and temporary condition of partial or complete
inundation of normally dry land areas from the overflow of inland
or tidal waters; the unusual and rapid accumulation of runoff or
surface waters from any source; or mudslides which are caused or
precipitated by accumulations of water on or under the ground.
Flood, "100 year ": A flood that, on the average, is likely to
occur once every 100 years, (i.e., that has a one - percent chance of
occurring each year). Also referred to as "100 year storm" and as
the "Base Flood ".
Flood plain: The area of land inundated with water in a 100 -year
storm.
Floodway: The channel of a river or other watercourse and the
adjacent land areas that must be reserved in order to discharge the
base flood without cumulatively increasing the water surface
elevation more than one foot.
Floodway Map: A map produced by FEMA which delineates the flood
boundary and floodway.
Fort Worth Drainage Manual: The City of Fort Worth Storm Drainage
Criteria and Design Manual.
Freeboard: A factor of safety usually expressed in feet above a
flood level for purposes of flood plain management.
Frequency: The average frequency statistically determined for
which it is expected that a specific flood level or discharge may
be equalled or exceeded.
HEC I Analysis: A computer watershed model developed by the
Hydraulic Engineering Center, U.S. Army Corps of Engineers, which
contains several methods with which to simulate surface runoff and
river- reservoir flow in river basins and flows in urban areas.
HEC II Analysis: A computer backwater flood model developed by the
Hydraulic Engineering Center, U.S. Army Corps of Engineers, which
calculates water surface profiles for steady, gradually varied
flows in natural or man -made channels.
Mean Sea Level: The National Geodetic Vertical Datum (NGVD) of
1929 or other datum, to which base flood elevations shown on a
community's Flood Insurance Rate Map are referenced.
1 - 3
Mudslide: A general and temporary movement down a slope of a mass
of rock or soil, artificial fill, or a combination of these
materials caused or precipitated by the accumulation of water on or
under the ground.
Retention: The retention of stormwater on a site or within a
project shall be interpreted as a permanent restrainment of runoff
with no anticipation of runoff over an extended period of time.
Ultimate Conditions: The level of development anticipated upon
full development of all land with a watershed. Ultimate conditions
are typically determined by reference to existing use and projected
land uses on vacant or nonconforming properties based upon existing
zoning or the City Land Use Plan, whichever is more intense.
Unless specifically stated otherwise, all storm water run -off
calculations required within this ordinance should be based on
ultimate conditions of development.
1 - 4
ARTICLE 2
DRAINAGE STUDIES
Section 2.01 General
A. It is the policy of the City to require a drainage study on
all property to be developed in the City. The City has
endeavored to associate the complexity of the drainage study
with the finality of the proposed development. Developments
that are in a "preliminary" or "feasibility" phase will
require drainage studies that are less demanding in calculated
precision than those that are in a "final" state of proposal.
Section 2.02 Preliminary Drainage Study
A. When Required: It is the policy of the City to discuss and
conceptually resolve drainage issues of a development at the
Preliminary Plat stage. The applicant shall submit a
Preliminary Drainage Study with the submittal of any
Preliminary Plat of a proposed development. A Preliminary
Drainage Study may also be required by the City when reviewing
the merits of a change in zoning, especially when the proposed
use is more intense than that shown on the Land Use Plan.
This Preliminary Drainage Study would accompany the Concept
Plan, or Site Plan as required by the Zoning Ordinance.
Approval of the Preliminary Plat or Concept Plan may be
contingent on the acceptability of the solutions proposed by
the Preliminary Drainage Study.
B. Qualification to Prepare Study: The Preliminary Drainage
Study shall be prepared by a Professional Engineer registered
in the State of Texas and experienced in Civil Engineering and
having a thorough knowledge of the study of drainage issues.
The Preliminary Drainage Study shall be signed and sealed, and
dated by the person preparing the study.
C. Requirements: The requirements for a Preliminary Drainage
Study shall be established and periodically updated by the
Director of Public Works. These requirements shall be
maintained by the Director in written form and shall be
available free of charge to any interested person.
D. Exemptions: The Director of Public Works may waive the
requirement of the Preliminary Drainage Study or may limit
certain requirements where the Director determines that such
requirements are not necessary for a proper review of the
development.
2 - 1
Section 2.03 Final Drainage Study
A. When Required: It is the policy of the City to resolve
drainage issues of a development at the Final Plat stage. The
applicant shall submit a Final Drainage Study with the
submittal of any Final Plat, Plat Revision, or Plat Showing of
a proposed development. Approval of the above mentioned plats
may be contingent on the acceptability of the solutions
proposed by the Final Drainage Study.
B. Qualification to Prepare Study: The Final Drainage Study
shall be prepared by a Professional Engineer registered in the
State of Texas, experienced in Civil Engineering and having a
thorough knowledge of the study of drainage issues. The Final
Drainage Study shall be signed, sealed, and dated by the
person preparing the study.
C. Requirements: The requirements for a Final Drainage Study
shall be established and periodically updated by the Director
of Public Works. The requirements shall be maintained by the
Director in written form and shall be available free of charge
to any interested person.
D. Exemptions: The Director of Public Works may waive the
requirement of the Final Drainage Study or may limit certain
requirements where the Director determines that such
requirements are not necessary for a proper review of the
development.
Section 2.04 Computer Models
A. General: The Director of Public Works, upon a recommendation
from the City Engineer, may request that a drainage computer
model be submitted with the Final Drainage Study. Where a
computer model is requested along with the Final Drainage
Study, approval of both the Final Drainage Study and the
Computer Model shall be a prerequisite to the filing of the
plat in the county plat records.
B. HEC I Analysis:
1. When Required: A HEC I Analysis shall be submitted on
any property which has 1,000 acres draining into the
tract at its lowest point.
C. HEC II Analysis:
1. When Required: The Director of Public Works may require
the submission of a HEC II Analysis in the following
situations:
2 - 2
a. Where the property to be developed is adjacent to
or is potentially impacted by a FEMA designated
floodway or floodplain; or
b. Where the property being developed contains natural
drainage channels.
2 - 3
ARTICLE 3
DRAINAGE DESIGN CRITERIA
Section 3.01 Drainage Manual Reference
A. Fort Worth Drainage Manual: The City hereby adopts the most
current City of Fort Worth Storm Drainage Criteria and Design
Manual as the reference for all calculations required by this
ordinance. The City shall not maintain copies of the Fort
Worth Drainage Manual for the use of developer's Civil
Engineers. It is the City's intention by this adoption to
help standardize the approach to storm drainage design and use
a Drainage Manual which is familiar and accessible to most
engineers practicing in this region.
B. Highway Department Hydraulic Manual: In cases not covered by
the Fort Worth Drainage Manual, the Hydraulic Manual prepared
and compiled by the Texas Highway Department's Bridge
Division, dated March, 1962, with subsequent revisions, may be
used. The City shall not maintain copies of the Hydraulic
Manual for distribution.
C. Retention and Detention: Retention and detention design
criteria shall be determined on a case -by -case analysis using
standard civil engineering practices.
Section 3.02 Design Storm Frequency_
A. R.O.W. /Easement Capacity: Streets and storm drainage systems
shall be designed using a design storm of 100 -year frequency.
The capacity of the street R.O.W. and /or drainage easements
and the storm sewer pipe working in combination must be
designed for a capacity to safely contain storm runoff
resulting from the 100 year storm. However, no streets will
be permitted with the pavement below the 100 -year flood
elevation of a water course.
B. Street Capacity: Whenever the capacity of a street to the top
of any curb is exceeded by storm runoff from a 5 -year fre-
quency storm, a storm sewer shall be designed and constructed.
1. Arterial Streets: The storm sewer system shall be
designed so as to prevent ponding on one 12 foot lane in
each direction. There shall be no cross -flow drainage at
intersections with Arterial Streets.
2. Collector Streets: The storm sewer system shall be
designed so as to prevent ponding on at least one 12 foot
3 - 1
. .
lane. There shall be no cross -flow drainage with greater
than 20 cfs at intersections with Collector Streets.
C. Storm Sewer Capacity: Storm Sewers shall be designed for a
storm frequency of 5 years.
1. In a case where this 5 -year design frequency for storm
sewer in combination with surface flow capacity of the
available R.O.W. and easements does not contain the
100 -year storm, then the storm sewer shall be increased
in size and designed for a capacity of a higher
frequency, of up to 25 years.
2. At such point where the runoff exceeds the capacity of
the 25 -year storm sewer in combination with the available
R.O.W. and easements, then one of the following
approaches shall be used.
a. The storm sewer shall be designed to carry the
runoff from a 100 -year storm; or
b. The storm drainage improvements shall be designed
as an open channel.
3. Over private property: Any drainage intended to cross
private property shall be contained in a closed system
designed to handle the 100 -year storm unless an
alternative system can be proposed which is approved by
the Director of Public Works. Adequate easements shall
be dedicated for this facility.
D. Open Channels: All open channels are to be designed to handle
the runoff from a 100 -year storm and said channels shall have
a minimum of one (1) foot freeboard to the top of the bank.
E. Culverts and Bridges: Culverts and bridges shall be designed
to handle the runoff from a 100 -year storm. Given that both
culverts and bridges may solve a particular situation, it
shall be up to the Director of Public Works to determine which
type of structure shall be used. Bridges shall require a two
(2) foot freeboard between the low point of the bridge and the
100 -year water surface elevation. For any culverts, the
headwater (hydraulic gradient) shall be a minimum of one (1)
foot below the adjacent top of curb.
Section 3.03 Time of Concentration
A. Average Conditions: Under average conditions the time of
concentration to the upstream end of a drainage system shall
coincide with Table II -2, "Minimum Inlet Time of
Concentration ", page II -5 of the Fort Worth Drainage Manual.
3 - 2
B. Unusual Circumstances: Under circumstances which produce
times of concentration in excess of those shown in Table II -2,
the time of concentration shall be determined through the use
of Figure II -I, "Nomograph for Time of Concentration ", page
II -6 of the Fort Worth Drainage Manual. The following
cautions should be exercised when using this Nomograph:
1. The path along which the time of concentration is deter-
mined should be representative of the drainage area as a
whole. On some irregularly shaped drainage areas it is
possible to find the time of concentration along a
particular path which is representative of only a small
portion of the drainage area. This time of concentration
may greatly exceed the time of concentration which is
more representative of the drainage area as a whole.
2. Overland flow shall be considered channelized at such
time as the distance traveled exceeds 200 feet.
Section 3.04 Land Use Runoff Coefficients
A. Fully Developed Criteria: All runoff coefficients shall be
based on land uses as if fully developed with those types of
uses.
B. Land Uses: All runoff coefficients shall be in accordance
with the existing zoning or the current Land Use Plan approved
by the City, whichever coefficient is more intense.
C. Requirements: The requirements for a Preliminary Drainage
Study shall be established and periodically updated by the
Director of Public Works. These requirements shall be
maintained by the Director in written form and shall be
available free of charge to any interested person.
D. Overdeveloped Tracts: When it is determined by the Site Plan
review process or other City review, that the actual
development of a particular property will create a runoff
factor greater than that shown for the tract as determined
above, retention or detention may be required on the tract
prior to the issuance of a certificate of occupancy.
Section 3.05 Miscellaneous Design Criteria
A. Pipe Design Criteria:
1. Minimum Pipe Size: The minimum storm drain pipe diameter
shall be eighteen (18) inches.
2. Minimum Velocity: The minimum velocity with the pipe
3 - 3
flowing full shall be three (3) feet per second.
3. Changes in Pipe Size: Pipe crowns at changes in pipe
size should be set at the same elevation.
4. Vertical and Horizontal Curves: Vertical curves in the
conduit shall not be permitted. Horizontal curves shall
be permitted only when the alignment meets the pipe manu-
facturer's criteria for curves.
B. Manhole Requirements: Manholes shall be located at intervals
not to exceed 500 feet for pipe 24 inches in diameter or
smaller. Manholes shall preferably be located at street
intersections, sewer junctions, changes of grade and changes
of alignment. Manholes for sewers greater than 24 inches in
diameter shall be located at points where design indicates
entrance into the sewer is desirable; however, in no case
should the distance between openings or entrances be greater
than 1,200 feet.
C. Street Crowns: Street crowns shall be reduced for
approximately one hundred (100) feet on each side of valleys.
D. Culverts: All culverts shall require approval by the City
Engineer prior to the issuance of a culvert permit. All pipe
within public R.O.W. shall be reinforced concrete pipe (RCP)
and shall be jointed together properly (Ram -Nek, Talco or
equal). Reinforced concrete box culverts shall also be
allowed. All culverts shall be inspected during installation
by the public works department. In the event that a
particular situation calls for an "arch- pipe" structure, said
structure shall only be made of an galvanized metal.
1. End Sections: All culverts of twenty -one (21) inches in
size or larger shall have 6:1 safety end sections. The
ground around the upstream end section shall be graded to
match the 6:1 slope. The ground around the downstream
end section shall be graded to a 4:1 slope. Culverts
less than twenty -one (21) inches in size shall have Type
B end sections as shown in the Texas Highway Department
Hydraulic Manual Drawing CH -11.
2. Private Property: Culverts entirely within private
property may use corrugated pipe of a shape and size
approved by the Director of Public Works.
E. Lakes: Approval to develop in any area subject to inundation
by a lake must be obtained from the appropriate agency
responsible for that particular lake before the city grants
its approval. Agencies that should be contacted include U.S.
Army Corps of Engineers, Tarrant County Water Control Board,
3 - 4
Texas Water Commission and the Trinity River Authority.
Regardless of approvals obtained from those agencies listed
above, no filling, development or construction in any area
subject to inundation by a lake shall occur without the
approval of the Director of Public Works. No impoundment of
water shall be allowed within any street right -of -way. Any
lakes that are retained on the property shall maintain one (1)
foot of freeboard. The Director of Public Works may require
any studies necessary to determine that filling, development
or construction does not have any detrimental effect on
adjacent, upstream or downstream properties and any building
shall be protected.
F. Easements: Drainage easements having a minimum width of 15
feet shall be dedicated on the plat or by separate instrument
prior to any construction of the drainage improvements.
Location of easements shall be in accordance width the
subdivision Ordinance No. 483. Minimum easement requirements
for storm sewer pipe shall be as follows:
Minimum Easement
Pipe Size Width Required
36" and under 15 feet
42" through 54" 20 feet
60" through 66" 25 feet
72" through 102" 30 feet
over 102" 3.5 times diameter
This width may be modified by the Director of Public Works
based upon the soil types, pipe depths, overflow impact, other
utilities or similar influences.
1. Outfall extension: Drainage easements will generally be
required to extend at least twenty -five (25) feet past an
outfall headwall to provide an area for maintenance
operations. Drainage easements along a required outfall
channel or ditch shall be provided until the flowline
"daylights" on natural grade. The minimum grade allowed
on an outfall channel or ditch will be 0.5 foot per 100
feet.
2. Open Channel Easements: Channel improvements shall be
located in easements of sufficient width to contain the
ultimate 100 year storm plus one (1) foot of freeboard.
3. Maintenance Access: Additional easements may be required
to provide access to the drainage easements. This may
include not only access to the drainage easement but also
additional width along the easement where necessary.
Access to channel easements will typically be at the
3 - 5
intersection with a City street R.O.W..
4. Detention /Retention Ponds: Detention and retention ponds
shall be designed to contain the ultimate 100 -year storm
plus one (1) foot of freeboard. Easements for detention
and retention ponds shall be negotiated between the City
and the property owner upon review of adequate drainage
information.
G. Diversion or Impoundment: All drainage systems shall be
designed to prevent the diversion or impoundment of the
natural flow of surface water in a manner that damages the
property of another by the flow of the water diverted or
impounded. The Director of Public Works shall place in each
developer's agreement a provision requiring the developer to
comply with all applicable laws, including, but not limited
to, Section 11.086, Texas Water Code. In addition, the
Director of Public Works shall place on each plat that
receives final approval, a statement that reads as follows:
Compliance with the provisions of the city's Storm Drainage
Policy does not relieve a person of the responsibility of
complying with all other applicable laws, including, but not
limited to, Section 11.086, Texas Water Code.
3 - 6
ARTICLE 4
OPEN CHANNEL POLICY
Section 4.01 General
A. Channel Types: The type of channel shall be determined on the
basis of the "CA" factor and other data presented by the
applicant's engineer.
B. Building Line Limitations: All open channels shall contain
the 100 -year storm and one (1) foot of freeboard outside of
any adjacent building lines.
C. Easement Widths: All open channels to be maintained by the
City shall be in easements of sufficient width to contain the
100 -year storm and one (1) foot of freeboard within the
channel. The Director of Public Works may require an
additional 10' width on one side of the channel to provide a
relatively flat, grassed area to be used for maintenance
purposes.
Section 4.02 Natural Channels
A. With No Improvements: Natural creek channels may be approved
without channel improvements provided that: 1) serious
erosion is not expected (i.e. velocities less than 6 fps
unless an approved soils test indicates that a higher velocity
would be acceptable); 2) sufficient easements are dedicated
to provide protection of adjacent properties or facilities;
3) floodway easements are determined in accordance with this
ordinance; 4) arrangements have been made for perpetual
maintenance by the adjacent property owners and /or the creek
channel has been dedicated and accepted by the City; and 5) in
the judgment of the Director of Public Works, the appropriate
use of the neighboring property or the health and safety of
such persons affected will not be substantially injured.
B. Erosion Control: Such creeks may be modified by cutting and
filling, or to provide for erosion and flood control facili-
ties, in accordance with plans approved by the Director of
Public Works.
All erodible areas shall be protected by laying the slopes
back to a maximum slope of 3 feet horizontally to 1 foot
vertically with grass sod cover; or by installing concrete,
rock, masonry, or retaining walls to an elevation at least one
(1) foot above mean water elevation.
4 - 1
Section 4.03 Earth Channels
A. General: Earth channels may be approved provided that: 1)
the velocity of flow will not produce serious erosion (less
than 6 fps unless an approved soils test indicates that a
higher velocity would be acceptable); 2) sufficient easements
are dedicated to provide protection of adjacent properties or
facilities; 3) floodway easements are determined in
accordance with this ordinance; 4) arrangements have been made
for perpetual maintenance by the adjacent property owners
and /or the channel has been dedicated and accepted by the
City; and 5) in the judgment of the Director of Public Works,
the appropriate use of the neighboring property or the health
and safety of such persons affected will not be substantially
injured.
B. Soils Tests: Soils tests and borings may be required to
determine the probability of erosion. Table VII -1 in the Fort
Worth Drainage Manual shall be used as a guide for determining
the highest velocity of flow for the particular condition
which will not produce serious erosion.
C. Channel Shape: Earth channels shall have a trapezoidal shape
with a minimum bottom width sufficient to carry the run -off
within the easements while maintaining side slopes no steeper
than 3 feet horizontal to 1 foot vertical (4 to 1 preferred).
The channel shall be of sufficient depth and size to contain
the 100 -year storm plus one (1) foot of freeboard.
D. Pilot Channel: A reinforced concrete pilot channel as deter-
mined by the Director of Public Works may be required.
E. Slope Treatment: The side slopes shall be smooth, free of
rocks, and contain a minimum of 6 inches of topsoil. The
slopeshall be block sodded for a for a distance of 2 feet
adjacent to the pilot channel. Gobi blocks, fiber -mats, or
other such similar materials, may be used in lieu of block
sodding. The balance of the slope shall be seeded.
Section 4.04 Concrete Lined Channels
A. Channel Shape: Channels shall be trapezoidal in shape and
lined with reinforced concrete in accordance with City
standard specifications. Side slopes shall be a maximum of 1
foot horizontal to 1 foot vertical (2 to 1 preferred) or as
approved by the Director of Public Works. The lining shall
typically extend such that the 100 -year storm plus one (1)
foot freeboard is within the concrete lining but alternatives
may be considered when presented with adequate data by the
applicant's engineer. Channels shall have a minimum bottom
width of eight (8) feet.
4 - 2
B. Curves or deflections: The design of the channel lining shall
take into account the super elevation of the water surface
around curves and other changes in direction.
4 - 3
ARTICLE 5
ON -SITE IMPROVEMENTS
Section 5.01 Owner's Responsibility
A. Upstream Drainage: The land owner or developer shall be
responsible for designing on -site improvements sufficient to
handle all storm drainage flowing on such person's property.
This responsibility includes the drainage directed to that
property by prior developments as well as drainage naturally
flowing through the property by reason of topography.
B. Installation Costs: The owner of a tract of land shall be
responsible for the cost of installation of all drainage
improvements within the boundaries of their development. This
shall include any oversizing of structures to accommodate
upstream runoff.
C. Construction Plans: Construction plans for the development
shall include plans for all drainage improvements. These
plans shall be reviewed by the City Engineer and approval
shall be granted by the Director of Public Works prior to
beginning construction.
D. Maintenance Bonds: The owner or developer shall provide
maintenance bonds for all drainage improvements. Maintenance
bonds shall be 50% of the cost of the improvements and for a
two -year duration.
5 - 1
1. All existing drainage structures shall be noted as to
type, size, and current condition.
2. All proposed critical drainage structures shall be
determined as to type and size.
3. An accurate acreage breakdown of the entire watershed and
each of the tributary watersheds leading into the flow
line of the main watershed shall be noted.
C. Cost Determination: Included with the off -site study shall be
an itemized cost estimate of all critical structures within
the watershed. This shall include, but not be limited to, the
following:
1. Cost of removing existing structures where applicable.
2. Cost of repairing or improving existing structures where
applicable.
3. Cost of installing new structures.
4. Cost of improving or maintaining existing open channels.
5. Cost of designing the structures and preparing
construction plans and documents sufficient to obtain
competitive bids.
6. Cost of preparing applicable portion of off -site study.
7. Cost of easement acquisition.
Section 6.05 Off -Site Easement Acquisition
A. Any necessary easements not dedicated by platting shall be
procured by separate instrument by the developer or property
owner. If the developer or property owner cannot obtain a
required off -site easement, then the developer or property
owner may request that the City assist in the acquisition.
The developer must first make an offer in writing, based on
the fair market value of the easement, to the property owner
from whom the easement is being acquired. The City Council
shall determine, in its sole discretion, whether the city will
participate in the acquisition of required off -site easements.
In any event, all costs of obtaining the easement shall be the
responsibility of the developer or property owner and the City
must be reimbursed for any costs incurred.
6 - 2
Section 6 . 06 Cost Participation for Off-Site Improvements
A. Adjacent Downstream Structures : The developer shall install
and pay for all required off-site drainage structures which
are adjacent to the development . The Developer will be
responsible for all costs associated with the installation of
such drainage structures, including, but not limited to,
engineering, surveying, testing, easement preparation,
easement acquisition and inspection. If the off-site drainage
structures serve acreage within the watershed other than the
proposed development, the Developer shall be eligible to
receive a pro rata rebate from future developments utilizing
such drainage structures which develop within five years after
completion of such drainage structures . At the expiration of
the fifth year, the Developer will no longer be entitled to
receive any reimbursement for the cost of construction of
drainage structures . Each subsequent development within the
drainage basin which utilizes the adjacent drainage structures
shall pay a pro rata cost of the structures . The pro rata
cost for each subsequent development will be determined on a
cost per acre basis by calculating the proportional area of
the development encompassed in that subdivision to the total
area within the drainage basin utilizing the drainage
structures .
B. Other Upstream and Downstream Improvements : The developer of
any tract of land within a watershed serviced by a critical
structure, shall participate in the cost of improving that
structure on a percentage formula having a per-acre of
watershed coefficient and a land use coefficient as follows .
1 . Within the watershed serviced by said critical structure,
areas shall be delineated showing the more intense land
use of the existing zoning or the proposed Land Use Plan.
2 . The "CA" shall be determined for the entire watershed as
a whole to the point of design for the critical
structure .
3 . The "CA" factor shall be determined for the subject
tract .
4 . The "CA" factor for the subject tract shall be taken as
a percentage of the "CA" factor for the entire watershed.
This shall be the percentage responsibility of the
subject tract .
5 . This percentage shall then be multiplied with the cost of
the critical structure to obtain the dollar amount of
contribution required by the subject tract .
6 - 3
Section 6.07 Construction of Off -Site Improvements
A. Remaining capacity in critical structure: When the critical
structure being impacted by the proposed development still has
capacity to handle the increase in runoff created by the
development, the developer shall not be responsible for the
construction improvements to the structure or replacement
thereof. The developer will be responsible for satisfying the
monetary obligation for participation as outlined in the
previous section.
B. No capacity remaining: Should the proposed development create
runoff which exceeds the capacity of the critical structure,
it shall be the responsibility of the developer to construct
the ultimate improvements to said structure which are
necessary.
1. Prior Contributions: The City shall be responsible for
transferring all funds from previous developments'
contributions to the specific structure to the developer
who must construct said improvements.
2. Future Refunding: The City shall be responsible for
procuring additional participatory funds from other
developers within the watershed and transferring these
funds to the developer responsible for constructing the
improvements. This obligation shall only extend for a
period of five years from the date of acceptance of the
structure by the City.
6 - 4
ARTICLE 7
DRAINAGE STUDY REVIEW PROCESS
Section 7.01 Submittal
A. Coordination of Processing: The drainage studies required in
this ordinance shall be submitted to the Public Works
Secretary for processing. The applicant shall receive all
review letters from the Public Works Secretary and shall
submit any revisions to the Public Works Secretary.
B. Fees: All fees required for administration and review of
drainage studies required by this ordinance shall be in
accordance with the Fee Schedule adopted by the City Council.
C. Reproductions: The Public Works Secretary shall maintain the
requirements for reproductions to be submitted. It shall be
the responsibility of the applicant to verify these
requirements prior to submittal.
Section 7.02 Responsibility for Review
A. Director of Public Works: The Director of Public Works shall
have the responsibility of initiating the review by the City
Engineer. He shall additionally have responsibility for all
negotiations with the owner during the review process.
B. City Engineer: The City Engineer shall have responsibility
for determination of technical compliance with City ordinances
and standard engineering practices. He shall provide a
written review of all drainage studies requested for review by
the Director of Public Works. The City Engineer shall work
closely with the applicant's engineer to help the applicant
resolve all deficiencies in the study and shall provide an
updated review upon resubmittal of the revised drainage study
by the applicant.
C. Approval: The Director of Public Works shall have final
approval of the drainage study. City Council shall have final
approval of all cost participation requirements for the
development.
D. Appeals: The applicant may appeal decision of the Director of
Public Works regarding the drainage study by filing a written
appeal to the City Council, expressing the points of
disagreement and proposed alternatives. This written appeal
shall be scheduled on the next available City Council meeting,
at which time the applicant shall make a presentation
7 - 1
supporting his appeal. The determination by the City Council
shall be final.
Section 7.03 Impact on Subdivision Approval
A. Downstream Hazards: Where it is anticipated that additional
runoff incidental to the development of the subdivision will
overload an existing downstream drainage facility, whether
natural or man -made, and result in hazardous conditions or
damage to property, the Planning and Zoning Commission and /or
City Council may withhold approval of the subdivision
preliminary or final plat until appropriate provisions have
been made to accommodate the problem, and plans have been
provided which include all necessary offsite improvements,
including storm sewer systems, channel grading, driveway
adjustments, culvert improvements, etc.
7 - 2
ARTICLE 8
RETENTION AND DETENTION POLICY
Section 8.01 General
A. Intent: It is the City's intent to consider retention and
detention of stormwater runoff as a solution towards the
adequate control of potential hazards created by stormwater
runoff.
B. Scale of Review: The retention and detention of stormwater
shall be considered on two different scales of development as
follows:
1. Development Scale: The larger development scale project
shall consider the use of stormwater management basins,
retention ponds and similar solutions for controlling
peak runoff.
2. Site - Specific Scale: The site - specific scale shall
involve those tracts which are not being subdivided or
have been subdivided prior to the implementation of this
ordinance.
Section 8.02 Development Scale Projects
A. Review Process: Development scale projects shall be reviewed
during the plat review process.
B. When Required: Retention /detention within a development may be
required for any of the following reasons or other reasons
deemed appropriate:
1. Existing homes, businesses, or other habitable structures
downstream are currently at a flood level, or are at an
elevation such that any increase in upstream runoff would
put them into a flood situation.
2. The runoff intensity of the development is greater than
the runoff intensity used for the development while
preparing the conceptual drainage plan.
3. The developer may choose to provide retention /detention
within the development of his own accord.
C. Solutions: It shall be the responsibility of the developer's
engineer to propose a reasonable design solution and provide
necessary calculations to justify the proposal. Options to
8 - 1
specifically consider may include the following:
1. Check Dams: Small dams or drop structures constructed of
concrete, gabions, or rip -rap and located in a
drainageway. Check dams are typically used in areas of
excessive grades to reduce velocity, to provide some
storage, and reduce erosion.
2. Detention Ponds: Detention ponds are designed to contain
water only during runoff periods. The high runoff flows
from intense rainfalls are captured in the control basin
and released slowly over several hours.
3. Retention Ponds: Retention ponds are designed to have
flood storage capacity in addition to their normal
contents. During dry weather, retention ponds are used
for recreation or aesthetic purposes.
Section 8.03 Site - Specific Scale
A. Review Process: The application for building permits shall
initiate a Site -Plan review process on all non - residential
properties. This review shall include a review of the site
drainage.
B. When Required: The City may require retention /detention of
site drainage for any of the following reasons or other
reasons deemed appropriate:
1. Overdeveloped Runoff: The runoff from the site is
greater than the runoff "C" factor for the use as
determined in Section 2.03 of this ordinance.
2. Change in Use: The use of the site has increased in
intensity of runoff since the approval of the
subdivision, or since the approval of this ordinance.
3. Existing homes, businesses, or other habitable structures
downstream are currently at a flood level, or are at an
elevation such that any increase in upstream runoff would
put them into a flood situation.
4. The runoff intensity of the development is greater than
the runoff intensity used for the development while
preparing the conceptual drainage plan.
5. The developer may choose to provide retention /detention
within the development of his own accord.
C. Solutions: It shall be the responsibility of the developer's
professional engineer to propose a reasonable design solution
8 - 2
and provide necessary calculations to justify the proposal.
Options to specifically consider may include the following:
1. Parking Lot Storage: This might include depressions in
the pavement allowing temporary ponding of water and con-
trolled discharge into the drainage system. This might
also include either central or peripheral grassed areas
to hold and filter runoff water. Any accumulation in a
paved area shall maintain a depth of less than one (1)
foot.
2. Rooftop Storage: Highly impervious areas such as indus-
trial and commercial districts, having buildings with
flat roofs, may allow this type of temporary storage.
3. On -Site Detention Ponds: Grass lined depressions where
water is typically dispersed through evaporation or
percolation.
Section 8.04 Regional Detention Retention Ponds
[ADD REQUIREMENTS]
8 - 3
ARTICLE 9
MISCELLANEOUS PROVISIONS
Section 9.01 Contingent Warning
The degree of flood protection required by this ordinance is
considered reasonable for regulatory purposes and is based on
engineering and scientific methods of study. Larger floods may
occur on rare occasions or flood heights may be increased by
man -made or natural causes, such as bridge openings restricted by
debris. This ordinance does not imply that areas outside
floodplain areas or land uses permitted within such districts will
be free from flooding or flood damages.
Section 9.02 Maintenance of Drainageways and Drainage Facilities
A. Natural Drainageways and Drainage Easements With No
Structures: It shall be the responsibility of the owner to
routinely maintain all creeks, streams and natural
drainageways and all unimproved drainage easements on his
property. This shall include periodic removal of fallen
trees, limbs and underbrush, periodic rough mowing, removal of
trash and debris, and general upkeep to maintain a positive
flow of storm water within the drainageway or easement. The
responsibility of the landowner hereunder shall not include
any maintenance which requires specialized or heavy equipment.
B. Drainage Easements With Surface Structures: It shall be the
responsibility of the city to maintain all surface structures
within a drainage easement. The landowner shall maintain all
portions of the drainage easement which are not improved, in
accordance with the requirements set forth in paragraph A
above.
C. Bar Ditches and Culverts: Although these items are typically
found in R.O.W. dedicated to the City, maintenance of these
items shall be the responsibility of the individual landowner.
This shall include periodic removal of underbrush, periodic
rough mowing, removal of trash and debris, and general upkeep
of the bar ditch or culvert to maintain a positive flow of
storm water within the bar ditch or culvert. Maintenance
shall also include periodic cleaning of culverts to remove all
sediment or other hindrances to the flow of water. Culverts
shall be replaced by the owner should any structural failure
in the culvert potentially impede the flow of water.
D. Failure to Maintain: lien.
9 - 1
1. It shall be unlawful for the landowner to fail to
maintain a natural drainageway, drainage easement, bar
ditch or culvert as required in this section. The city
may notify the landowner of a violation of this section
by notice given:
(a) personally to the landowner in writing; or
(b) by letter addressed to the landowner at the
landowner's post office address; or
(c) if personal service cannot be obtained or the
landowner's post office address is unknown:
(i) by publication in the official newspaper
at least twice within ten (10)
consecutive days; or
(ii) by posting the notice on or near the
front door of the main residence or
building on the property on which the
drainageway, drainage easement, bar ditch
or culvert is located; or
(iii) by posting the notice on a placard
attached to a stake driven into the
ground on the property on which the
drainageway, drainage easement, bar ditch
or culvert is located.
2. Following the expiration of not less than ten (10) days
from the date of the notice, the city may enter upon the
property and may do such work as is required in this
section or cause the same to be done. In the notice of
a violation provided above, the city may inform the
landowner by certified mail, return receipt requested,
that if the landowner commits another violation of the
same kind or nature that poses a danger to the public
health and safety, on or before the first anniversary
date of the notice, the city, without further notice, may
abate the violation at the landowner's expense and assess
the expense against the property. If a violation covered
by a notice under this paragraph occurs within the one
year period and the city has not been informed in writing
by the landowner of an ownership change, then the city,
without notice, may take any action permitted by this
paragraph and assess the expenses as provided in
subparagraph (3) below.
3. A bill for the actual cost incurred and a reasonable
administrative charge incurred by the city resulting from
9 - 2
the performance of the work shall be mailed to the
landowner and must be satisfied within thirty (30) days
of the date of mailing of such bill. In the event such
bill has not been satisfied within the specified period,
the mayor may file a statement with the county clerk of
Tarrant County of the expenses incurred in the abatement
of the above described condition on the premises and the
City shall have a privileged lien on any property upon
which such expense is incurred, second only to tax liens
and liens for street improvements. The lien statement
shall state the name of the landowner, if known, and the
legal description of the property. Said privileged lien
shall bear interest at the rate of ten percent (10 %) per
annum from the date such payment is due. For any such
expenditure and interest as aforesaid, suit may be
instituted and recovery and foreclosure had in the name
of the City of Southlake, and the statement made as
aforesaid or a copy thereof shall be prima facie proof of
the amount expended for any such work performed by the
City.
9.03 Compliance with other laws
In addition to the requirements of this ordinance, the
developer and /or landowner must meet all applicable requirements of
the federal National Pollutant Discharge Elimination System (NPDES)
storm water permitting program set forth in the federal Clean Water
Act, 33 U.S.C. Sec. 1342 et seq., as amended, as implemented in 40
C.F.R. 122.26(b) (14)(x), as amended, or any other federal or state
laws or regulations applicable to drainage or storm water run -off.
Section 9.04 Enforcement
A. Development Permit: No development shall be allowed within
the limits of the flood plain until the developer /owner has
received a development permit from the City. This shall
include grading plans and other requirements as outlined by
the Director of Public Works.
B. Building Permit: No building permits shall be issued for
properties which have not been analyzed for potential
flooding, do not have applicable floodway or floodplain limits
shown, potentially require a finished floor elevation in
excess of that proposed, or do not fulfill the requirements of
this ordinance.
C. Final Plat Filing: The City shall not approve any plat for
filing in the County Plat Records that does not meet the
requirements of this ordinance.
9 - 3
Section 9.05 Modifications and Variations
A. Compliance: Where the City Council finds that compliance with
these regulations would cause unusual hardship or
extraordinary difficulties because of exceptional and unique
conditions of access, location, shape, size, drainage, or
other physical features of the site, the requirements of this
ordinance may be modified to mitigate the hardship, provided
that the public interest is protected and the modification
meets the general spirit and intent of this ordinance.
1. This section shall not be interpreted to permit the
development of land which is inherently unsuitable for
the use proposed.
2. No modification shall be granted which will have the
effect of preventing the orderly subdivision of other
land in the area in accordance with the provisions of
this ordinance.
B. Discretion of City Council: At the discretion of the City
Council, the normal standards and requirements of this
ordinance may also be modified in the case of a Planned Unit
Development. Such departures from the standards specified may
be made only when the City Council finds that the plan
provides for convenient and safe access, adequate space for
recreation, and adequate light and air; and offers all
essential utility services and necessary public and other
facilities; and is in conformance with all provisions of City
ordinances which specifically apply to Planned Unit
Developments.
Section 9.06 Liability Disclaimer
A. General: All of the regulations provided in this ordinance
are hereby declared to be governmental and for the health,
safety and welfare of the general public. Any member of the
City Council or a City official or employee charged with the
enforcement of this ordinance, acting for the City of
Southlake in the discharge of his duties, shall not thereby
render himself personally liable; and he is hereby relieved
from all personal liability for any damage that might accrue
to persons or property as a result of any act required or
permitted in the discharge of his said duties.
B. Professional Liability: The Professional Engineer responsible
for preparing the drainage study shall retain liability for
said drainage study, regardless of any action taken by the
City or the City's Engineer concerning the study.
9 - 4
Section 9.07 Injunctions
The City shall have the right to institute an action in a court of
competent jurisdiction to enjoin the violation of any provision of
this ordinance within it's municipal boundary or within its
extraterritorial jurisdiction, and this remedy shall be in addition
to any penal provision in this ordinance or in the Code of the City
of Southlake.
9 - 5
Fort Worth Star-Telegram
400 W.SEVENTH STREET•FORT WORTH,TEXAS 76102
40 STATE OF TEXAS
my of Tarrant
Before me, a Notary Public in and for said County and State, this day
personally appeared DAWN M. RIVERA Billing Specialist for the Fort Worth
Star-Telegram, published by the Star-Telegram Inc. at Fort Worth, in Tarrant
County, Texas; and who, after being duly sworn, did depose and say that the
following clipping of an advertisement was published in the above named
paper on the following dates:
DATE AD INVOICE NO. DESCRIPTION AD SIZE INCH/LINE RATE AMOUNT
JUN 24 2696381 CL• 358 1X71 L 71 .46 32.66
j u n e _2 0_t h r u_j u n e 2 4
P. 0• #-ORD .__-605 ••
ORDINANCE NO.605
—
' AN ORDINANCE ADOPT-�
'SPOLIC}Y FOR THE DRAINAGE
— — PROVIDIINGE19RA NAGS...
DESIGN CRITERIA,. PRO-
VIDING FOR THE DSIGN •
1 CONSTRUCTION AND
MAINTENANCE OF ON- '
SITE AND OFF-SITE
DRAINAGE CHANNELS
AND OTHER DRAINAGE
IMPROVEMENTS- PRO-
VIDING FOR COST PAR-
TICIPATION FOR OFF-.... . ............. _.....__. .......... ..._..... ......._...
SITE DRAINAGE'IMPROVEMENTS; PRO- SIGNED _
:VIDING REQUIREMENTS
,, , cs,... .
FOR RETENTION AND DE-
SUBSCRIBED AO , VENCFORTOI"EMAFNTE--E ME, THIS THE 24Y9 AY OF JUNE, 1994
ID NANCE OF DRAINAGE
WAYS AND DRAINAGE NOTARY PUBLI
_... EASEMENTS;PROVIDING, __..._..._ .. ...-._....._._.
FOR VARIATIONS TO TH'S
ORDINANCE• PROVIDING
FOR THE REPEAL OF OR-
DINANCENO.482•PROVID- TARRANT COJN , TEXAS
ING THAT THIS ORDI- --'-
1 NANCE SHALL BE
CUMULATIVE OF ALL OR- ""+
y h
DINANCES•PROVIDING A o�p�••4L®
-----------------.__..__�._....__—._ .;SEVERABILITY CLAUSE;,.__...---_-----
�_:= �,_ LINDA l(: I3lEY1NS - -
PROVIDING A VIOLATIONS
, my
FOR VIOLATIONS ��•P
HEREOF; PROVIDING Al
® at a„j COMMISSION EXPIRES
SAVINGS CLAUSE PRO- �ti�. —SEPIEM®ER 43;"}gy)
—._ VIDING FOR PUBLICA-
TION —.— ��r R,-, •tF
IN THE OFFICIAL ti,", t}e
NEWSPAPER; PROVID-
ING FOR PUBLICATION IN
PAMPHLET FORM• AND
' PROVIDING AN EIFEC-,
TIVE DATE.
TEAR SEcri?N -ION AND RETURN THE LOWER PORTION WITH YOUR PAYMENT
' - - trlon who Any perso fiam or torpors-
- violates,disobeys,. -- - - -- - - - - - -- - - - -
omits neeg9lects or refuses to
comp(ywitliorwhoreslststhe -
% ,, enforcementofanyofihepro-
\,,k vislonsofthlsordlnanceorthe REMIT TO : 400 W . SEVENTH, FW, TX 76102
�; ad rm hererainagePolicyadopt-
is' ' ed herein shall be fined not
// ��y more than Five Hundred Dol-
' Fars (5500,00) for each of- �C1���NUM
, v i �v 9 )vFv��gpt�raalv�Fpf (�1 TW �iFY� EU1NA
'vim` oAse.Each day that a voa- !n1'u',w'���u7 T�n�L�Zi,CKn Zn� 7B AN 7�/�M`•/�•/t7'I /� V /�•X'U XNX-2051
- r tlonisppeermittedtoexlsTshall 0,4,
'r constituters arateoffense.®�� +,: PASSED AND APPROVED �a
? n'•','+; BY THE CITY COUNCILOF ACCOUNT AMOUNT
26963'81 , !✓r' THE CITY OF SOUTH- NUMBER CIT57 DUE 32. 66
,q, e F! , LAKE THIS THE 21STDAY,I
OF JUNE,1994.
N' %, ° Gary Flckes,
r�; Manor of South lake 1, 1
,,� ,1•,,, Attest:Sandra L.LeGrand • tl+=
,• `,,, , City Secretary
/ \ Approved as to form:
�'- E.Allen Taylor Jr.,
'', _City Attorney
CITY OF SOUTHLAKE
667 N CARROLL AVE 32. 66
SOUTHLAKE TX 76092-9595 THISAMOUNPLEASE T
ATTN: SANDY LEGRAND
N PLEASE WRITE IN AMOUNT ENCLOSED
fort Worth Star-Telegram
400 W.SEVENTH STREET•FORT WORTH,TEXAS 76102
IIIIIISTATE OF TEXAS
ty of Tarrant
Before me, a Notary Public in and for said County and State, this day ,
personally appeared DAWN M. RIVERA Billing Specialist for the Fort Worth
Star-Telegram, published by the Star-Telegram Inc . at Fort Worth, in Tarrant
County, Texas; and who, after being duly sworn, did depose and say that the
following clipping of an advertisement was published in the above named
paper on the following dates :
•
DATE AD INVOICE NO. DESCRIPTION AD SIZE TOTAL INCH/LINE RATE AMOUNT
_ _ . - _
p NOTICE OF
JUN 10 2687798 CL• 358 OTICC�jEApIS��HNNEREl��BYGIV- 1X 76L 76 • 46 34 . 96
D
•Un 10 PERSQNSthaftheClttvCoun-
cIl of the Cit of Southlake,
Texas,will be olding a public
hearing during the Regular
City onCouncil meeting1, 114, eg begin-
ning at 7:00p.m.The meeting
will be held in the City Counci i —
Chambers of City Hall, 667
North Carroll Avenue,South-
lake,Texas.The purpose of!__
—._.._ ..
" - --the u c eargnglsfoconsld-
er tORDIINANC ordinances: '•
AN ORDINANCE ADOPT-
ING A STORM DRAINAGE
POLICY FOR THE CITY OF
SRIN , RTHSEPOVDIG-FO • •
SUBMISSION OF PRELIMI-
NARAGETAND FINAL DRAIN- ----
AGE STUDIES• PROVID-
ING 9
DRAINAGE DESIGN I
CRITERIA,PROVIDING / •
FOR THE DESIGN CON-,T- S THE 10 TI: D 0 F DUNE 9
SUBSCRIBED A D SWORN llSTRUCTION AND MAINTE
' F ON-SITE AND
CHANNETOLS AND OTHER NOTARY PUBLIC__
'DRAINAGE IMPROVE-,
CEST SLAROV DIPNAGTFOR AD
FOR OFF-SITE DRAINAGE TARRANT COUN , TEXAS
— ---- IMPROVEMQENTS• PRO-
VIDING
TENTION AND DE —
V GINOFORTHEMAINRTE- 4Y �� lINOA K. BlEVIMS
NANCE OF DRAINAGE- - r.f.„6.....
— r
w�„��/� Y
WAYS AND DRAINAGE • r;: CVRif711en)I{/1� CXPIR S
i EASEMENTS;
OR NANCE_ PROVIDING 'ei•., �\ N
ORIDNANCE PROVIDING —� —T _vy?rF•_.!_.. SEPTEMBER 13, 1997
-------` FOR THE REPEAL OF OR-! y ,,,,.•. --`-- - - -.--_.-- ---- - ----
&14T1/10
NIN EEN0.4 PROVID-
ING THAT THIS ORDI-
NANCE SHALL BE
CUMULATIVEC OF ALL ROVID-
DINANCES; PROVIDING
TEAR ALONG THI!OFFICtIALI PUBLICATION
ETURN THE LOWER PORTION WITH YOUR PAYMENT
PROVIDING FOR PUBLI-I__
CATION IN PAMPHLET
FORM AND PROVIDING •
r AN EFFECTIVE DAl E.
SECTION REMIT TO: 400 W . SEVENTH FW, TX 76102
Any person firm or corpora ,
✓ ' tion who violates, disobeys,
/ omits neeggiects,or refuses to \
complYwithorwhorFort WorthStar enforcement ofanvoo•+ visionsof thlsordinahe StormDrainagePoliserit,t-
2 ad herein shall be fined not
2 6 8 7 7 9"8 ' '! 1 more than
Pl0 Hundred e �Doof_ ACCOUNT AMOUNT
�v' yr 40419.." e 4, +f Tense.Each day a violation Is NUMBER C I T 5 7 DUE. 34 . 96
\\ k I� ptuts a tedtoe a of-teal)constl-
� // Y ���--, -3.• I tote, separate offense.
,,y x tub 1 CItd of Southlake,Texas
� d{° r I Sandra L.LeGrand
g y / �+ City Secretary I
• CITY OF SOUTHLAKE
667 N CARROLL AVE PLEASE PAY 34 . 96
SOUTHLAKE TX 76092-9595 THIS AMOUNT ,
ATTN: SANDRA" L LEGRAND
l
X PLEASE WRITE IN AMOUNT ENCLOSED