HomeMy WebLinkAboutResolution No. 2006-24 RESOLUTION NO. R2006-24
A RESOLUTION ADOPTING A DESIGN CRITERIA MANUAL FOR
THE CITY OF FRIENDSWOOD, TEXAS; CONTAINING STANDARDS
FOR THE DESIGN, CONSTRUCTION AND INSTALLATION OF
PUBLIC INFRASTRUCTURE AND RELATED FACILITIES AND
IMPROVEMENTS WITHIN THE CITY; AND REPEALING CITY OF
FRIENDSWOOD RESOLUTION NO. R2005-05, PASSED AND
RESOLVED ON THE 17� DAY OF JANUARY 2005, AND ALL OTHER
RESOLUTIONS OR PARTS OF RESOLUTIONS INCONSISTENT OR IN
CONFLICT HEREWITH.
* * * * *
WHEREAS, the City Council has determined a need for the adoption of comprehensive
and concise standards covering the design, construction, and installation of public infrastructure
and related improvements within the City; and
WHEREAS, the City has determined that such improvement standards and requirements
should be,to the extent practicable, incorporated into a single document; and
WHEREAS, attached hereto is that certain City of Friendswood Community Development
Department"Design Criteria Manual,"which document contains certain design, construction and
installation standards for public infrastructure and related improvements incident to City
construction projects and subdivision and other development within the City's jurisdiction; now
therefore
BE IT RESOLVED BY THE CITY OF COUNCIL OF THE CITY OF FRIENDSWOOD,
TEXAS:
Section 1. The facts and matters set forth in the preamble of this Resolution are
hereby found to be true and correct.
Section 2. That certain City of Friendswood Community Development Department
"Design Criteria Manual," dated August 2006, a true and correct copy of which is attached
hereto and for all things made a part hereof, is hereby adopted. The standards and related
documents contained and referred to therein shall control and are hereby established as minimum
design, construction, and installation standards for certain public infrastructure and related
improvements within the City of Friendswood, Texas, for City projects and subdivision and
other related development. In the event of conflict between any provision of the Design Criteria
Manual and any ordinance of the City, or between any condition of plat or development approval
imposed by the City, the provisions of any such ordinance or term or condition of approval shall
control.
Section 3. The Director of Community Development shall maintain copies of such
Design Criteria Manual and related documents, which shall be made available, upon payment of
the reasonable costs of publication thereof, to any person requesting same. The Director is
further directed to periodically evaluate and review such standards and, when deemed necessary
and appropriate, recommend changes to the City Council.
Section 4. City of Friendswood Resolution R2005-05, passed and resolved the 17`n
day of January 2005, is hereby repealed. All other resolutions inconsistent or in conflict
herewith, are, to the extent of such inconsistency or conflict, hereby repealed.
PASSED,APPROVED,AND RESOLVED this llth day of September 2006.
Davi . H. Smith
Mayor
ATTEST:
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Deloris McKenzie, T C c� v
City Secretary * *
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R2006-24 2
CITY OF FRIENDSWOOD
COMMUNITY DEVELOPMENT DEPARTMENT
DESIGN CRITERIA MANUAL
AUGUST 2006
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Daniel S. Johnson, P.E., C.F.M.
City Engineer
Approved September 11, 2006
Resolution R2006-24
CITY OF FRIENDSWOOD
COMMUNITY DEVELOPMENT DEPARTMENT
Design Criteria Manual
September 11, 2006
Table of Contents
SECTION
I. Graphic Requirements
II. Wastewater Collection System Design Requirements
III. Water Line Distribution System Design Requirements
IV. Street Paving Design Requirements
V. Storm Drainage Design Requirements
VI. Site Development Requirements
VII. Modification Procedures
APPENDICES
A. Attachments
B. Figures
C. Parking Group Table
D. Qualified Tree List
City of Friendswood Design Criteria Manual
Community Development Deparhnent GRAPHIC REQUIREMENTS
SECTION I
GRAPHIC REQUIREMENTS
1.0 GENERAL
1 A 1 CHAPTER INCLUDES:
Graphic requirements for construction drawings.
1.02 REFERENCES
City of Friendswood Standard Details, latest version. These can be purchased from Community
Development or downloaded from www.ci.friendswood.�.us
1.03 DEFINITIONS
A. CADD (Computer Aided Drafting Design) - the preparation of documents utilizing
computer facilities for the production of drawings, plans, prints and other related
documents.
B. HCFCD—Harris County Flood Control District
C. GCCDD—Galveston County Consolidated Drainage District
1.04 DESIGN REQUIREMENTS
A. Provide a cover sheet for all projects involving three ar more design drawings (excluding
standard detail sheets). Plan sheet numbers shall be shown on the cover sheet or area key
map. Include a vicinity map to identify project locations. Also provide approval block for
the Director of Public Works and the Director of Community Development with a note
stating that approval is valid for 1 year only from date of signatures.
B. Drawings shall be prepared on nomina124 inch x 36 inch overall drawings.
C. Show service area on cover sheet or area map.
D. Final drawings shall be India ink on mylar or produced by CADD on mylar. The engineer
shall also submit, at the time of plan approval, an electronic version of the CADD drawing
on diskette or CD-ROM of the development showing all lot lines and associated lot
information, rights-of-way, easements, contours, utilities, and all drainage and paving
improvements.
E. Details of special structures (not covered by approved standard drawings, such as stream or
gully crossings, special manholes, or junction boxes, etc.) shall be drawn with vertical and
horizontal scales equal to each other.
Revised 9/11/2006 Section I Page I of 4
City of Friendswood Design Criteria Manual
Community Development Deparhnent GRAPHIC REQUIREMENTS
F. Each set of construction drawings shall contain paving and utility key drawings indexing
specific plan and profile sheets. Standard City drawings, where applicable, shall be
included. All sheets shall have standard title blocks. Where applicable, show HCFCD ar
GCCDD key drawings and numbers.
G. Draw key overall layouts to a minimum scale of 1 inch= 100 feet.
H. Plan stationing must run from left to right, except for short streets or lines originating from
a major intersection,where the full length can be shown on one street.
I. A north arrow is required on all sheets and should be oriented either toward the top or to
the right. This requirement is waived under the following conditions.
1. A storm or wastewater sewer whose flow is from west to
east or from south to north.
2. A primary outfall ditch drainage facility whose flow is from west to east or from
south to north.
3. Stationing is intended to start from the cardinal points of the compass and
proceed in the direction of construction.
J. Standard scales permitted for plans and profiles of paving and utility construction drawings
are as follows:
1. Major thoroughfares, streets with esplanades over 400 feet in length, or special
intersections/situation
1 inch=20 feet horizontal, 1 inch=2 feet vertical
2. Minor or residential single-family streets.
1 inch=20 feet horizontal, 1 inch=2 feet vertical
1 inch=40 feet horizontal, 1 inch=4 feet vertical
1 inch=50 feet horizontal, 1 inch= 5 feet vertical
3. Scales of Paragraph No. 2 above are minimum; larger scales may be used to
show details of construction.
K. Each sheet of the plan and profile shall have a benchmark elevation and description
defined, and a current flood zone determination statement.
L. The seal, date, and original signature of the Registered Professional Engineer responsible
for the drawings shall be required on each sheet developed by the engineer. The engineer
may use a stamped or embossed imprint for his/her seal; however, the embossed imprint
must be shaded such that it will reproduce on prints.
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City of Friendswood Design Criteria Manual
Community Development Department GRAPHIC REQUIREMENTS
M. A copy of the final plat for new developments shall be included with the final drawings
when submitted for final approval.
N. If a roadway exists where drawings are being prepared to improve or construct new
pavement or a utility, label the existing roadway width, surface type, and thickness, if
available without destruction of pavement. Pavement thickness can be ascertained by
caring with the core hole grout filled to protect pavement prior to construction.
O. Show all streets and/or road alignment on drawings.
P. Develop drawings to accurate scale showing proposed pavement, typical cross sections,
details, lines and grade, and all existing topography within street right-of-way, and any
easement contiguous with the right-of-way. At the intersection,the cross street details shall
be shown at sufficient distance (20-foot minimum distance outside the primary roadway
right-of-way) in each direction along cross street for designing adequate street crossings.
Q. Match lines between plan and profile sheets shall not be placed or shown within cross street
intersections including cross street right-of-way.
R. Natural ground profiles shall be shown as follows:
l. For privately-funded projects, center line profiles are satisfactory except where a
difference of 0.50 feet or more exists from one right-of-way or easement line to
the other, in which case, dual profiles are required.
2. For City of Friendswood projects, provide natural ground profiles for each right-
of-way line. Easement profiles shall conform to S-1 below.
S. Basic plan and profile sheets shall contain the following information:
1. Identify all lot lines, properiy lines, easements, right-of-way, and HCFCD or
GCCDD outfalls.
2. Label each plan sheet as to street/easement widths, pavement widths, pavement
thickness where applicable, type of roadway materials, curbs, intersection radii,
curve data, stationing, existing utilities (type and location), and any other
pertinent feature affecting design.
3. Show all utility lines 4 inches in diameter or larger within the right-of-way or
construction easement in profile view. Show all utility lines, regardless of size,
in the plan view including fiber optic cables.
4. Graphically, show flow line elevations and direction of flow for all existing
ditches.
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City of Friendswood Design Criteria Manual
Community Development Department GRAPHIC REQUIREMENTS
5. Label proposed top of curb grades except at railroad crossings. Center line
grades are acceptable only for paving without curb and gutters.
6. Curb return elevations for turnouts shall show in profiles.
7. The center line elevation at the property line of all existing driveways shall be
shown in profile.
8. Station all esplanade noses or the center line of all esplanade openings with
esplanade width shown-both existing and proposed.
9. The design of both roadways is required on all paving sections with an esplanade.
10. Station all PCs, PTs, radius returns, and grade change PIs in plan view. Station
all radius returns and grade change PIs in profile with their respective elevations.
T. Provide a pollution prevention plan with legend. See Site Development(Section VI)under
Design Requirements.
U. The Drainage Plan shall have a current FEMA flood zone determination statement.
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City of Friendswood Design Criteria Manual
Community Development Deparhnent WASTEWATER COLLECTION SYSTEM
SECTION II
WASTEWATER COLLECTION SYSTEM
DESIGN REQUIREMENTS
1.0 GENERAL
1.01 CHAPTER INCLUDES:
Criteria for the design of wastewater collection systems.
lA2 REFERENCES
A. Texas Commission on Environmental Quality (TCEQ)- "Design Criteria for Sewerage
Systems" -Texas Administration Code-Chapter 317 (current revision).
B. City of Friendswood Standard Details, latest version. These can be purchased from
Community Development or downloaded from www.ci.friendswood.tX.us
1.03 DEFINITIONS
This Chapter addresses the design of the wastewater collection systems within the public right-of-
way or a dedicated public easement. Sanitary sewers located on private properiy that are not in a
dedicated easement, are under the jurisdiction of the Plumbing Code, and will be
addressed/reviewed by the Building Official. Where used in these regulations, the following
terms shall be construed to carry the meanings given below:
A. Public Sewer - A closed conduit which conveys wastewater flow and which is located
within the public right-of-way or dedicated public easement. A public sewer (or public
sewer system)is intended to serve more than one(1) "owner".
B. Private Sewer - A closed conduit which conveys wastewater flow and is constructed and
maintained by a private entity(ies) (i.e., homeowner's association). Private sewers may be
located in areas such as a private street or common area. Private sewers are subject to the
design and construction requirements of the Plumbing Code and must discharge to a public
sewer.
C. Sewer Main-A sewer which receives the flow from one ar more lateral sewers.
D. Lateral Sewer-A sewer running laterally down a street, alley, or easement, which receives
only the flow from the abutting property.
E. Service Lead -A sewer which branches off a public sewer and extends to the limits of the
public right-of-way. It shall be construed as having reference to a public sewer branching
off from a main or lateral sewer to serve one or more houses, single-family lots, or other
types of small land tracts situated in the same block with the said main or lateral sewer, but
not directly adjacent thereto. Such a line shall never exceed 150 feet in length. If the sewer
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Community Development Deparhnent WASTEWATER COLLECTION SYSTEM
is designed to serve more than two houses, or the equivalent of two single-family
residences along a street, a lateral sewer as defined above shall be constructed.
F. Service Connection - A private sewer from a single source to the main or lateral sewer in
the street, alley, or easement adjacent thereto. Service connections are covered by the
Building code. It will be owned and maintained by the owner of the property being served
by said sewer.
G. Project Area-The area within the immediate vicinity of the public sewer to be constructed.
If, as an example, a public sewer were to be constructed within the public right-of-way, the
project area would extend 10 feet to either side of the public right-of-way. If as an
example, a public sewer is to be constructed within a dedicated easement adjacent to the
public right-of-way, the project area would extend 10 feet to either side of the dedicated
easement; depending upon the existing topographical elements, unless impacted by a
permanent structure (i.e.. telephone pole, trees, drainage ditches, etc.) If, as an example, a
public sewer is to be constructed within a side lot easement (if approved by the City), the
same criteria would apply as for a dedicated easement adjacent to public right-of-way.
H. Stack - A riser pipe constructed on main or lateral sewers which are deeper than 8 feet to
facilitate construction of service leads or service connections.
I. Force Main -A pressure-rated conduit(i.e. ductile iron pipe, pressure-rated PVC, etc.)that
conveys wastewater from a pump station to a discharge point.
1.04 DESIGN REQUIREMENTS
A. Drawings to be furnished:
Before any main or lateral sewer is constructed and before a permit will be issued for the
construction of same, plans and profiles of the proposed sewer shall be prepared and
submitted to the City for approval. On projects within the City limits, the tracing shall
become the properiy of the City and shall remain on file in the City for the use of any
person who may be interested in same.
B. Details to be shown on drawings:
The detailed plan view will show the exact location of the proposed line in the street, alley
or easement with respect to the edge of the particular right-of-way,the transit base line,and
any nearby utilities, major landscaping, and other structures affecting construction.
C. Main and Lateral Sewers
1. Sewers in curved easements, easements defined by property lines and combined
easements containing other public utilities must be shown both in detailed plan and
profile views.
2. The profile should show other underground and surface utilities and facilities,both in
parallel and at crossings; the size, grade of the proposed line,the elevation of same to
hundreds of a foot at all manholes,changes of grade and dead-ends; and the proposed
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City of Friendswood Design Criteria Manual
Community Development Deparhnent WASTEWATER COLLECTION SYSTEM
finished grade over the sewer. It should show the actual ground line as it exists prior
to construction of the sewer. Where proposed fill or cut is contemplated, the
proposed new ground line should be shown as a separate line from the actual ground
line. Type of pipe and bedding shall comply with City of Friendswood Standard
Specifications and Standard Details.
3. Where sewers are to be placed between existing pavement and the street right-of-way
(or interiar easement line) ar under existing pavement ar topping, show the existing
ground line at both sides (or the closest side or sewers near the edge) of the right-of-
way or adjacent sewer easement.
D. Sewer mains-plan and profile required
1. Sanitary sewer layouts for single-family residential subdivisions should use a scale of
100 feet or less per inch. A scale of 200 feet per inch may be used provided the
following information is shown on the layout:
a. All easements containing or buffering sanitary sewers are shown at points of
size change; all manhole locations are shown.
b. The sewer alignment shall accurately reflect the relative location of the sewer
as shown on the detailed plan view.
c. All service leads that cross street pavement or serve adjacent properly are to be
shown on the layout. The detail plans and profiles shall show the flow lines of
all service leads at the street or easement right-of-way.
d. The number and size of the lots depicted on both the overall sewer layout sheet
and the individual plan and profile sheets shall match the number and size of
the lots depicted on the final plat after recordation.
e. On the overall sanitary sewer layout sheet the size and direction of flow for all
existing and proposed sewers shall be shown.
£ The location of the proposed sewer within either the public right-of-way, a
dedicated easement adjacent to the public right-of-way, or side lot easement(if
allowed by the City).
g. The overall sanitary sewer layout sheet shall show the area, in acres, which the
proposed sewer(s) is (are) designed to serve. Include a location map that
references the average to nearby major thoroughfare and boulevard streets. The
scale of the location map shall be 1 inch=2,000 feet ar less.
2. Commercial subdivision sanitary sewer layouts for large areas and with a scale of 400
feet or more per inch must have an additional set of layouts at not more than 200 feet
per inch, with match lines and a small index map showing which portion of the overall
layout that each sheet's layout represents.
3. Acceptable horizontal scales far the detailed plan and profile views are 10 feet, 20 feet,
40 feet and not more than 50 feet maximum per inch. Horizontal scale for major
thoroughfares and boulevards shall be 1 inch=20 feet or less.
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Community Development Deparhnent WASTEWATER COLLECTION SYSTEM
4. Acceptable vertical scales for detailed profile views are 2 feet, 4 feet, and not mare
than 5 feet maximum per inch unless otherwise approved. Vertical scale for major
thoroughfares and boulevards shall be 1 inch=2 feet or less.
5. The plan view shall show, at a minimum, the following information for the project
area:
a. All topographical features;
b. Stationing for the proposed sewers;
c. All existing utilities(i.e.telephone, gas,power, etc.);
d. Any significant landscaping and/or other structures which might impact
construction and/or construction related activities;
e. The width and type of all existing and proposed easements;
£ All proposed service leads;
g. The limits of bore and/or tunnel;
h. Locations where pressure pipe is to be installed for water line crossings;
i. Drawings for single-family residential subdivisions shall show the proposed
location, by stations, of all service leads, service connections, and stacks. The
distance from the sewer or transit base line station to the nearest existing
manhole shall be shown in the plan view or on an additional sewer layout sheet
with a scale no more than 1 inch= 100 feet;
6. The profile view shall show, at a minimum, the following information for the
project area:
a. Underground and/or surface utilities/facilities which are either parallel to the
proposed sewer ar cross the proposed sewers;
b. The proposed sewer's diameter and grade for each manhole section;
c. The flow line elevation for all sanitary sewers at each manhole;
d. The rim elevation of all existing and proposed manholes;
e. The flow line elevation at each sheet "break" (i.e., from one sheet to another);
£ Type of pipe bedding/backfill shall be noted on each plan/profile sheet;
g. The finished grade for proposed and existing pavement where "fill" and/or
"cut" is proposed, the proposed new ground line should be shown as a separate
line from the existing ground line;
h. The existing ground line for the "near side" of the public right-of-way where a
sewer is to be placed between the edge of existing pavement and the edge of the
public right-of-way;
i. The existing ground line at the centerline of the proposed sanitary sewer where
a sanitary sewer is to be placed within an existing easement. Show any
proposed and/or existing pavement.
j. The flow line elevation of all service leads where it crosses the edge of the
public right-of-way or the dedicated easement adjacent to the public right-of-
way;
k. The limits of bore and/or tunnel;
1. Locations where pressure pipe is to be installed for water line crossings;
in. The location of special backfill and/or proposed stacks shall be identified by
"stations" indicated on the design plans.
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Corrvnunity Development Deparhnent WASTEWATER COLLECTION SYSTEM
n. The location of stacks shall be labeled with stations.
E. Service leads
1. Service leads shall be at the properiy line between two (2) adjoining lots, or as
directed by the City. A single 6-inch service lead located at the property line
between two (2) adjoining lots would serve two (2) single-family residences with a
wye placed at the end of the service lead. Do not extend the wye clean-outs beyond
the edge of either the public right-of-way or dedicated easement.
2. Any service lead extension of more than 50 feet parallel to the street right-of-way
shall be treated as a lateral sewer.
3. Service leads from developments with more than 17,500 gallons-per-day flow shall
discharge into a proposed or existing manhole. Where the flow line of the service is
30 inches or greater above the flow line of the manhole, provide a standard drop to
manhole.
a. Service leads shall be provided to serve each lot within proposed
development inside the City limits.
b. Service leads shall be 6 inches in diameter(minimum). If the length of a service
lead exceeds 100 feet or the width of the public right-of-way by more than 20
feet, the minimum diameter shall be 8 inches and a manhole shall be utilized for
connection to the public sewer.
c. Service leads with a diameter of 6 inches shall utilize "full body" fitting
(extruded or factory-fabricated) for connection to the proposed public sewer or
an approved saddle-type connector for connection to an existing public sewer.
d. Saddle-type connectors shall be installed with the "stub" oriented between the
"spring line" (3 o'clock and 9 o'clock positions) and 45 degrees from the "spring
line" ("1:30" and "10:30" positions). Tees (aka, "full body fittings") shall be
oriented in the same manner.
e. The service lead shall be designated to minimize the use of bends as site
conditions will permit.
£ Service leads exceeding the limits defined in 1.04.E.2. shall have a manhole at
each end; as well as, a plan/profile drawing for each right-of-way crossing. All,
or part, of these service leads which are located in a public right-of-way, alley or
dedicated sanitary sewer or public utility easement may be treated as a public
sewer; depending upon the location of the terminal manhole and any intermediate
manholes.
g. For all existing lots (which are not served in accordance with these guidelines)
that need a service lead, if the distance to the nearest existing sewer is less than
50 feet,the service lead is under the jurisdiction of the Plumbing Code.
F. General Requirements.
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City of Friendswood Design Criteria Manual
Cormnunity Development Deparhnent WASTEWATER COLLECTION SYSTEM
1. Sanitary sewers within the City of Friendswood's jurisdiction shall allow for orderly
expansion of the system and shall conform with the comprehensive water and sewer
plan for the City of Friendswood.
2. Sewers shall be sized based on the minimum requirements set out in this standard
and the standard wastewater flow rates as established by the City of Friendswood.
3. All sewers shall conform to the minimum requirements of the Texas Department of
Health, "Design Criteria for Sewerage Systems".
4. Sewers shall be separated from water lines by a ininimum of nine (9) feet. Where
the minimum separation is not maintained, refer to Section 7 for allowable
clearances. Sewers crossing utilities other than water, a minimum of six (6) inches
of clearance must be maintained.
5. The public sanitary sewer, as maintained by the City of Friendswood, shall be
defined as all sewers, including stacks and service leads, that serve more than one
sewer connection, that are located in public easements or street right-of-ways, and
that are installed in accordance with these Standards.
6. Sanitary lines greater than 6 inches require stacks with 5 feet minimum cover.
(Stacks are to be shown on plans with stations). Place stacks and wyes or tees as
shown. Where no stacks are shown, it is the responsibility of the licensed plumber
to place a City approved saddle for connection to the line and the responsibility of
the City Inspector to determine that such saddle is water tight and properly installed.
7. Materials and construction to conform to latest City of Friendswood specifications
with all amendments thereto, including standard leak test.
8. Unless noted otherwise, all public sewers and service leads shall be embedded in
cement stabilized sand; to 6 inches below the pipe, 12 inches above the pipe and to
6 inches on each side. All such bedding shall be compacted to 95% standard proctor
density. The cross-section so described herein shall be termed the "embedment
zone."
9. Backfill all excavation areas/trenches under or within 1-foot of existing or proposed
pavement with cement-stabilized sand from the top of the pipe "embedment zone"
to the bottom of the subgrade. Cement-stabilized sand must develop 100-psi
compression at 48 hours. Backfill shall be compacted to 95% standard proctor
density.
10. The location of all special backfill and of proposed stacks shall be shown by stations
in the drawings.
11. Construction notes shall designate the kind and class of pipe with exceptions to the
construction notes to be shown on the plan and profile sheets.
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Community Development Deparhnent WASTEWATER COLLECTION SYSTEM
12. Non-sanitary sewer easements ar fee strips such as pipeline, power company,
drainage district, railroad, etc., are in and of themselves insufficient and
unacceptable to permit laying to sanitary sewers and/or force mains across or along
the underlying private property or restricted non-sanitary use type of public
property.
13. The final determination as to that portion of a street, alley, or easement to be
occupied by a proposed sewer rests within the City. The City Engineer will take
into consideration existing, planned and proposed facilities such as manholes,
pavement, pipe/conduits, along with existing trees, shrubs, or other unique surface
conditions when arriving at a decision.
14. Where an easement far a public sewer ends at a public right-of-way, the last
manhole shall be extended into the public right-of-way at a minimum of 2 feet
beyond the property line; or as close to the public right-of-way as possible due to
acceptable clearances required for other utilities(i.e.,water line and storm sewers).
15. The drawings for the sewer shall show the location of any existing known pipe or
duct that might interfere with the construction of the sewer and call to the attention
of the City any known obstacles that might be encountered in constructing the sewer
in any location under consideration. The Professional Engineer shall determine the
existence of pipes, ducts and/or obstacles from a visual survey on the ground plus
research of all public records and private records when available.
16. All sanitary sewer mains shall be constructed utilizing pressure rate pipe, SDR 26,
unless specifically approved by CiTy Engineer.
17. In new developments, sanitary sewer lines shall be centered in sanitary sewer line
easements.
G. Line Size
1. The minimum pipe diameter for a public sanitary sewer shall be 8 inches.
2. Four-inch service leads shall be confined to the limits of the lot which they serve
and shall serve only the equivalent of one single-family lot. No 4- inch sewer shall
be laid in any street, alley, or right-of-way.
3. Six-inch service leads shall not serve more than the equivalent of two single-family
lots or other types of small land tracts.
4. Four-inch and six-inch service leads far single-family residential lots shall have a
minimum grade of 0.70 percent.
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Community Development Deparhnent WASTEWATER COLLECTION SYSTEM
5. For commercial service leads such as street bores, submit a copy of the approved
plumbing drawings to establish the required size of the line. The minimum size lead
shall be 6 inches.
6. All main and lateral sewers will end in manholes, except for special and/or unusual
situations and subject to specific approval by the City.
7. All sewer lines shall be laid at a size and depth to conform to designs permitting an
orderly expansion of the sewer system of the City and so as to avoid a duplication of
lines in the future.
8. The City shall be the final judge as to sizes and depths required and exceptions to
"lateral service leads" as previously defined.
H. Line Depth
1. The sewer should be laid with the top of the pipe a minimum of 3 feet below
finished grade or top of curb,whichever is lower.
2. Sewer laid in street rights-of-way with curb and gutter paved streets shall have a
minimum cover of 4 feet from the top of the pipe to the top of the curb to anticipate
future sewer extension.
3. Sewers laid in street right-of-way with crowned roads and side ditches shall have a
minimum cover of 5 feet from the average ground line at the adjacent street right-of-
way to the top of pipe.
4. Where the minimum cover as specified in paragraphs H, 1,2, and 3 above is not
possible,the sewer shall be laid in Class 150 (150 psi)pressure pipe or rigid factory
made pipe with cement stabilized sand as shown in standard detail. Ductile iron
pipe shall be lined with either a polyethylene or polyurethane coating as approved
by the pipe manufacturer and applied by either the pipe manufacturer or an
approved application. The minimum liner thickness shall be 40 mil.
5. Maximum depth for 8 inch, 10 inch, and 12 inch collection lines shall be 20 feet
from average ground surface to pipe invert. Depths greater than 20 feet are subject
to approval by the City Engineer if justified for site-specific reasons during the
preliminary engineering phase of the project design.
I. Line Grades
1. The following table lists the minimum grades for 6 inch - 27 inch public sewers.
The minimum grade is based on a minimum full pipe velocity of 2.0 feet per second
(fps). The maximum grade is based on a maximum full pipe velocity of 10.0 feet
per second (fps). In both cases, the Manning Formula has been used with an "n" of
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Community Development Deparhnent WASTEWATER COLLECTION SYSTEM
0.013. The use of different pipe materials will not alter the use of 0.013 for the
purpose of the Design Manual.
Inside Dimension (I.D.) Minimum Slope(in Percent)
of Pipe in Inches to Develop V=2.3 ft./sec.
6 0.70
8 033
10 0.25
12 0.20
15 0.15
18 0.11
21 0.09
24 0.08
27 0.06
Far sewers larger than 27 inches in diameter,the Professional Engineer of recard
shall determine the appropriate grade utilizing the Manning Formula, n = 0.013
and a full pipe velocity of 3.0 fps.
J. Manholes
l. All manholes shall be precast concrete, unless the Professional Engineer submits a
"cast in place" manhole design for review and approval by the City Engineer. All
precast manholes to incorporate a "boot" type connector for sewer diameters up to
24". For sewer diameters greater than 24 inches, utilize either the "boot" type
connector(if available)or an integral gasket. All precast manholes shall conform to
the latest ASTM requirements.
2. For all public sewers, manholes shall be placed at all changes in alignment, changes
in grade, junction points, and either at street, alley, or easement intersections as
designs may require.
a. Sewers laid in easements shall have a manhole in each street crossed by the
sewer.
b. The maximum distance between manholes shall be 350 feet for 8 inch to 48 inch
pipes diameters. Spacing for larger diameter mains than 48 inches shall be
determined on an individual project basis.
c. Sewers with the same, ar approximate flow line elevation shall intersect each
other at a 90-degree angle. However, where a true perpendicular intersection
cannot be obtained, and where the"entering"sewer intersects the receiving sewer
at, or about, the same flow line, one or more manholes shall be utilized to
maintain a minimum angle of 80 degrees at the point of intersection. When the
"entering" sewer is on the upstream side of the manhole, the minimum angle
between the sewers may be reduced to a 45 degree angle; provided:
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(1) A distinct flow channel can be maintained within the manhole when the
flowline elevations of the sewers are at, or within, one (1) pipe diameter
of the smaller pipe; or
(2) When the flow line elevation of the "entering" pipe is above the crown of
the "primary" sewer and clearance can be provided between the sewers.
d. Manholes shall be placed at all dead-end mains and laterals.
e. Criteria for connections to, and utilization of,manholes.
(1) Where manholes are utilized to facilitate connections between public
sewers, when possible the sewers shall either match the manhole's flow
line, match the elevation of each other's crown or utilize an "outside"
manhole drop.
(2) Connections between public sewers at the manhole shall adhere to the
following criteria when possible:
(a) The elevation of the crown of the discharging sewer shall either
match the elevation of the crown of the receiving sewer or be
approved as special cases by the City.
(b) A standard drop connection is required when the difference in
elevation between discharging sewer flowline and receiving
flowline is greater than 30 inches.
(3) The routing of service connection directly to manholes will be allowed
only where the flowline elevation of the existing sanitary sewer is more
than 10 feet below grade and there is no available stack and either
(a) The lot to be so connected is a single-family, owner-occupied,
single lot residence connection to an existing manhole; or
(b) The lot to be so connected is a single-family, owner- occupied,
single lot residence connecting to a proposed manhole at the end o
a cul-de-sac.
(4) When routing an approved service connection to a manhole (see Item
"3"), the wall penetration shall not be greater than 10 inches in diameter
and shall be cored and sealed using grout as approved by the Standard
Wastewater Products Committee.
(5) When routing an approved service connection to a manhole (see Item
"3"), the connections shall utilize a "drop (either inside or outside) and
shall adhere to the following criteria:
(a) The manhole wall penetration shall be a minimum of 10 feet
below the manhole rim elevation and shall not be greater than 10
inches in diameter;
(b) The drop shall be 6 inches in diameter and shall be constructed of
SDR 26 PVC pipe(ATSM D 3034-94);
(c) The drop shall be located 45 degrees from the upstream side of
the main sewer;
(d) An internal drop shall be affixed to the manhole wall utilizing
stainless steel bands and anchor bolts.
(e) An internal drop shall terminate with a 45 degree bend. Said 45
degree bend shall not extend below the "top of pipe" elevation of
receiving sanitary sewer and;
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Community Development Department WASTEWATER COLLECTION SYSTEM
(� The wall penetration (core) shall be sealed using a "grout" as
approved by the City.
(6) All public sewers shall terminate in a manhole. Clean-outs will not be
utilized except at the end of each service lead.
(a) The manhole cover shall have a minimum diameter of 32
inches.
(b) All sanitary sewer manholes shall have inflow protectors.
K. Lift Stations
1. Lift station design shall comply with the City of Friendswood specifications, with
a storage volume in the wet well equal to 1.5 times the peak design flow to the lift
station. Add 10%to account for volume displaced by pumps.
2. A startup package for the pumps shall be submitted to the Director of Public Works
before final acceptance. This package should also include a completed start up log
sheet with field and product data. See Attachment 1.
3. Minimum site size shall be 40 feet by 40 feet. Smaller sites, that are adjacent to
public rights-of-way are contiguous to green space or similar land use areas, may be
approved when adequate odor control provisions are provided.
4. Pumps shall be sized to operate at optimum efficiency. Minimum acceptable
efficiency at the operating point will be sixty percent (60%) unless specifically
approved by the City.
5. Operation and maintenance should be considered in the design of the station and the
location of the station.
6. Wet well working volume should be sized to allow for the recommended pump
cycle of six(6)minutes for each pump.
7. Prior to installation controls and equipment shall be approved by the Department of
Public Works.
8. Emergency operations should be considered. Provide fittings and a blind flange that
will be readily accessible for emergency bypass pumping.
9. The inlet structure shall be designed to minimize turbulence.
10. The velocity in the Force Main and riser pipes shall be less than 8 fps and greater
than 3 fps.
11. The wet well shall be sized to provide adequate clearance between the pumps (refer
to manufacturers recommended clearances).
12. A peak factor of four(4) shall be used for Lift Station design.
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13. A minimum of two (2) feet of clearance shall be provided between pumps and
between pump and wall.
14. Low water levels shall be at least six (6) inches above impeller; and higher if
required by manufacturer.
15. Complete immersion of submersible pump motor at low water level is preferred, if
possible.
16. Tie steel in Lift Station bottom to wall (includes caisson construction situation) to
provide watertight wetwell.
17. Nuts, bolts, chains and all other metal components within wetwell shall be stainless
steel,not carbon steel.
18. Vent pipe shall be eight (8) inches minimum diameter equipped with odor control
system.
19. The following Hazen-Williams Coefficient shall be used for various pipe types:
PVC New C= 160
10-year C= 140
DIP New C= 140
10-year C= 100
20. Provide board fence (either cedar ar heart redwood) with steel posts in concrete.
Fence shall be at least eight(8)foot high.
21. Entrance drive to be at least fourteen (14) feet wide concrete pavement. Provide
enough room to park inside lift station site.
22. Indicate method of drainage of site on site plan. Internal drainage, sheet flow and
valley gutter driveways are acceptable. Drain to street or storm sewer, never onto
adjacent private property.
23. Locate control panel and wetwell hatch above 100-year flood plain. Call out the
100-year flood plain elevation on the plans.
24. Stainless steel guide rails (ar other pump removal method that avoids entering
wetwell)are required for submersible pumps.
25. A tee, plug valve (ar gate valve), and blind flange assembly is required on the force
main on the downstream side of the discharge valves and header. This is required so
truck-mounted pumps can bypass the lift station pumps and piping while work is
being done.
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26. Bedding for PVC force main is cement stabilized sand.
27. PVC force mains must be AWWA C-900.
28. DIP force mains are to be bedded in bank sand and polyethylene wrapped.
29. When calculating headloss in force main and piping, use of K factars on fittings,
with the Hazen-Williams formula, is preferred.
30. Backfill structural excavations(wetwell, etc.)with cement stabilized sand.
31. Lift station site plans shall be submitted in scales of 1-inch= 5-feet or 1-inch= 10-
feet.
32. Provide a protective coating or concrete additive to interior walls of wetwell. The
Public Works Department shall approve coating or additive used.
33. Lift station shall be equipped with a telemetry system, approved by City and
compatible with existing system. A bubbler system shall be installed and connected
to telemetry system to monitor status of lift station.
34. Power supply to lift station shall be 3-phase(and 480 volts where possible).
35. A system of floats shall be provided to control pumps.
36. A pressure gauge suitable for application shall be installed on each discharge pipe.
1.05 APPURTENANCES -Reserved
1.06 SUBMITTALS
A. Preliminary design- submit the following for review and comment:
1. Copies of any documents which grant approval of exceptions to the City design
criteria.
2. Design calculations for line sizes and grades
3. Contour map for overall area.
4. Plan and profile sheets showing proposed improvements(City projects only).
5. Geotechnical soils report for the project(City projects only).
B. Final design-submit the following for approval:
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Community Development Department WASTEWATER COLLECTION SYSTEM
l. Final documents of the above plus plan and profile sheets and Geotechnical soils
reports for non-City projects.
2. Review prints.
3. Original drawings.
1.07 QUALITY ASSURANCE
A. Prepare calculations and construction drawings under the supervision of a Professional
Engineer trained and Licensed under the disciplines required by the drawings. The final
construction drawings must be sealed, signed, and dated by the Professional Engineer
responsible for the development of the drawings.
2.0 EXECUTION
2.01 RESEARCH REQUIREMENTS
A. Research existing utility and right-of-way information.
B. Verify that no restrictions exist that will deny approval of the project concept.
2.02 DESIGN ANALYSIS
A. Calculations of design flows for overall development project.
2.03 DRAWINGS
A. Drawings shall include layout sheets (3) with contours, plan and profile sheets, and detail
sheets for special items and treatment plants.
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Community Development Deparhnent WATER LINE DISTRIBUTION SYSTEM
SECTION III
WATER LINE DISTRIBUTION SYSTEM
DESIGN REQUIREMENTS
lA GENERAL
1.01 CHAPTER INCLUDES:
Criteria for the design of Water Lines
1.02 REFERENCES
A. Texas Commission on Environmental Quality (TCEQ), Water Utilities Division "Rules
and Regulations for Public Water Systems," latest revision.
B. American Water Works Association(AWWA).
C. National Sanitation Foundation(NSF).
D. Texas Department of Health.
E. Texas State Board of Insurance.
F. City of Friendswood Standard Details, latest version. These can be purchased from
Community Development or downloaded from www.ci.friendswood.�.us
1.03 DEFINITIONS
A. Water Line - Closed conduits designed to distribute potable water for human consumption
to various areas and provide fire protection. Line size and fire protection accessory
locations are dependent on distance from primary source and quantity of demand.
1.04 DESIGN REQUIREMENTS
A. Easements for water lines.
1. Lines shall be located within street right-of-way, permanent access easements with
overlapping public utility easements, easements adjacent to street rights-of way or
recorded water line easements.
2. When outside of a public street right-of-way or permanent access easement with an
overlapping public utility easement, easements must be dedicated and restricted far
water lines only.
3. When possible, easements should be contiguous with public rights-of-way.
4. Except for side lot easements, water line easements shall be contiguous to a paved
access.
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5. For water lines 12 inches or smaller located outside of street rights-of-way, one
minimum width of easement shall be 10 feet.
6. For water lines 16 inches or larger located outside of street rights-of-way, the
minimum width of easement shall be 15 feet.
7. For water mains located less than 5 feet from the right-of-way line, the outside edge
of a water line easement shall be located from the right-of-way line as follows:
14 inch and smaller pipe- 5 feet.
16 inch and larger pipe- 10 feet
8. Water lines along State rights-of-way shall be installed outside of the right-of-way in
a separate 10-foot minimum contiguous easement.
9. No back lot easements will be allowed for the installation of water lines, unless
specifically approved by the City.
10. Commercial Developments inside the City requiring on-site fire hydrants must
provide a minimum 15-foot water line easement for the water line and fire hydrant.
11. In new developments,water lines shall be centered in water line easements.
12. When using side lot easements, such easements shall be a minimum of 10 feet in
width, located on one lot or centered between lots. If centered between lots, the
water line maybe centered within the five feet of one lot, ar centered in the easement.
13. Location of a water main in an easement not adjoining a public right-of-way shall be
prohibited, except as specifically approved by the City of Friendswood. When
approved, these water mains will be centered in a 15 foot wide exclusive easement
restricted to water only.
B. Location of water lines
1. Locate within a street right-of-way.
2. Location of water lines within an easement - locate water lines in the center of a 10
foot minimum width dedicated waterline easement. Within a commercial
development inside the City, center water lines within a 15 foot easement. Obtain
approval for lines to be located in wider or multi-use easements.
3. When a water line is placed parallel to another utility line, other than a sanitary
sewer, the water line shall have a minimum of 4 feet harizontal clearance from
outside wall of the water line to the outside wall of the existing utility.
C. Water line size
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l. 6 inch lines may be used on dead-end lines within cul-de-sacs or if the line is less
than 1,000 feet in length and interconnected between two lines which are 8 inches in
size or larger. The maximum number of fire hydrants or flushing valves on any
length of 6 inch line is one.
2. 8 inch lines may be used for lines over 1,000 feet long or when 2 or more fire
hydrants or flushing valves are required.
3. 12 inch and lar�er lines - lines to be determined by the Professional Engineer (P.E.)
and City of Friendswood.
D. Dead-end lines
1. Dead-end lines within a public right-of-way.
a. On permanent dead-ends, other than cul-de-sacs, the line shall be 6 inches and
shall not exceed more than 500 feet in length from the closest interconnection
main line and shall terminate with a fire hydrant.
b. In permanent dead-end situations within cul-de-sacs, reduce pipe size
successively. Carry 8 inch pipe to the next to last hydrant,then use 6 inch pipe
to the line's end. Place the last service as near as possible to the end and install
a fire hydrant at the end of the 6 inch line. The maximum length of this
reduced line size configuration should not exceed 800 feet.
2. Dead-end lines with one on-site fire hydrant or flushing valve.
a. 6 inch lines may be used for lengths less than 200 feet provided domestic
service is taken from the end of the line.
b. 8 inch lines may be used for lengths greater than 200 feet but less than 500 feet,
provided domestic service is taken from the end of the line.
E. Depth of cover
1. 14 inch and smaller mains shall have a minimum cover of 4 feet from top of curb.
For open ditch roadway sections, 12 inch and smaller shall be installed at least 3 feet
below the ultimate flowline of the ditch or 6 feet below natural ground at the right-of-
way line,whichever is deeper.
2. 16 inch and lar�er mains shall have minimum cover of 5 feet from top of curb. For
open ditch roadway sections, 16 inch and larger mains shall be installed at least 3 feet
below the flow line of the ditch or 7 feet below natural ground at the right-of-way
line,whichever is deeper.
3. Changes in grade to clear other utilities or underground features may be made by
deflecting pipe joints. The maximum designed deflection shall be one-half('/2)of the
manufactures allowable deflection. If a depth greater than 8 feet to the top of the
pipes is required, a welded steel section will be used. The standard depth of cover
maintained on the water main and the grade change shall be made using the welded
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steel section. The installation of fittings for vertical deflections or changes in grade
shall not be allowed except with specific approval of the City of Friendswood.
F. Water line crossings
1. Public and private utility crossings other than sanitary sewer.
a. Where a water line crosses another utility other than a sanitary sewer, a
minimum of 6 inches of clearance must be maintained between the outside wall
of the water line and the outside wall of the utility.
2. Stream and Ditch Crossings
a. Elevated Crossings
(1) All water lines shall be steel or restrained joint metallic pipe and shall
extend a minimum of 15 feet beyond the last bend or to the right-of-way
line,whichever is greater.
(2) Elevated crossings are preferred to underground crossings.
(3) Use a separate elevated supporting structure for 16 inch and larger water
lines unless otherwise approved by the City. Locate the structure a
minimum of 10 feet from any existing or proposed structure.
(4) Support water lines on existing or proposed bridges. The following
criteria may be used for 12 inch and smaller lines when approved in
advance by the City.
(a) Have adequate structural capacity.
(b) Have sufficient clearance above the bent cap elevation far
installation under the bridge.
(5) Design elevated crossings with the elevation of the bottom of the water
line above the low chord of the nearest adjacent bridge or a minimum of
1 '/2 feet above the 100 year flood plain elevation,whichever is higher.
(6) Extend pipe from right-of-way to right-of-way for crossings.
(7) Provide sufficient span length to accommodate the cross section of future
widening of the stream or ditch, if available.
(8) Support the line on columns spaced to accommodate the structural
capacity of the pipe considering deflection and loading.
(9) Base column support design on soil capacity, spacing, loading, and
structural requirements.
G. Underground crossings
1. Provide a minimum 3-foot clearance above the top of the pipe to the ultimate flow
line of the ditch.
2. Provide sufficient length to exceed the ultimate future development of the stream or
ditch.
3. All water lines shall be steel or restrained joint pipe and shall extend a minimum of
15 feet beyond the last bend or to the right-of-way, whichever is greater and have
valves located on both sides of the crossing.
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H. State highway and county road crossings
1. Extend carrier pipe from right-of-way to right-of-way.
2. Use welded steel pipe or restrained joint pipe in steel casing under existing and future
roadways from a point 15 feet outside of the service road or outside of pavement
toward the right-of-way, to a similar point on the other side of the highway across the
right-of-way. For highway or roadway crossings with open ditch sections, extend the
casing from right-of-way to right-of-way.
3. State highway crossings shall be constructed in conformance with the requirements
of the Texas Department of Transportation.
4. When additional right-of-way has been acquired or will be required for future
widening, the casing, where required, should be carried to within 10 feet of each
future right-of-way line.
I. Street crossings
1. All water mains and sprinkler line crossings under major thoroughfare boulevards
shall be encased using a minimum of PVC pipe, SDR, as shown on the construction
detail for "Water Main Encasement." Welded steel pipe may be substituted on street
crossings,when specifically approved by the City of Friendswood.
2. Crossings under existing concrete streets, other than major thoroughfares, shall be
constructed by boring and jacking. PVC pipe shall be jacked into place with
equipment designed for that purpose. Water may be used to facilitate boring and
jacking operations. Jetting the pipe main into place will not be permitted. When
conditions exist that warrant an open cut across and existing street,the City Engineer
shall specifically approve the crossing.
3. All open cut installations under existing ar proposed streets shall be backfilled as
shown in the construction details.
4. All street crossings shall be constructed in accordance with construction plans
approved by the City. All street crossings shall be inspected by the City
Engineer. All street crossings shall meet the requirements of these standards.
J. Oil and gas pipeline crossings
1. Do not use metallic pipe when crossing oil or gas transmission lines unless a properly
designed cathodic system is implemented with City approval. Other pipe may be
used, regardless of depth, subject to approval by the City. Maintain a minimum 2
foot separation between the pipeline and waterline.
K. On-site fire loops within commercial and multi-family developments.
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Community Development Deparhnent WATER LINE DISTRIBUTION SYSTEM
1. For commercial and multi-family developments inside the City requiring on-site fire
hydrants, comply with the following requirements to allow maintenance and future
repair operations:
a. Do not allow placement of structures, paved parking or equipment pads over
the easement.
b. Provide 10 foot wide longitudinal pavement joint along easement lines where
the water line is located under driveway or street pavement.
L. Additional requirements
1. The carrier pipeline shall extend a minimum of 1 foot beyond the end of the casing to
allow flanged joints to be constructed.
2. For welded steel bends, extend steel pipe a minimum of 5 feet beyond the bend.
M. Auger(bore) construction
l. Use the following general criteria for establishing auger or bore sections:
a. Auger or bore sections shall be clearly shown on drawings.
b. Improved streets - use auger construction to cross the street regardless of
surface. Auger length shall be computed as roadway width at proposed bore
location plus 5 feet to either side of the roadway,where applicable.
c. Sidewalks - when the water line crosses under a sidewalk 4 feet or more in
width and in good condition, the sidewalk shall either be bored and jacked or
the sidewalk shall be removed and replaced to the City of Friendswood criteria,
whichever is cost effective. Bore and jack length shall be at least the width of
the sidewalk. The proposed type of construction shall be noted on the plans.
d. Bore Pits - Bore pits shall be at least 3 feet from back of curb and 5 feet from
the back of curb on a major thoroughfare. All bore pits shall be shored in
accordance with OSHA requirements. Bore pits and/or receiving pits to be
located in street or driveway paving, shall be shown on plans.
N. Water quality-overall system layout.
l. Circulation and flushing - The layout of the overall water distribution system shall
provide the maximum circulation of water to prevent future problems of odar, taste,
or color due to stagnant water.
a. Provide a source of fresh water at each end or at multiple points of a
subdivision. Provide ways to create circulation and place valves and fire
hydrants to allow simple flushing of all lines.
b. Avoid dead-ends whenever possible; when necessary, isolate dead-ends with a
line valve, keep as short as possible, and equip with a fire hydrant near the
line's end.
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c. Where stubs are provided for future extensions, isolate the stubs with a valve
and do not allow service connections to stubs until extended. Place one full
pipe joint between the valve and stub
d. Water mains shall be looped unless physically impossible.
e. All materials which come in contact with public drinking water in any stage
must conform with ANSI/NSF Standard 60. See Attachment 2.
£ Layout and size of all water mains shall be consistent with the overall layout
and phasing plan of the City's water system. The overall water system shall be
designed to maintain adequate pressure throughout the system.
g. In an unavoidable permanent dead-end situation, reduce the sizes of pipe
successively. Carry an 8-inch pipe to the next to last fire hydrant; use a 6 inch
PVC to the end of the line. Provide a fire hydrant at the end of the main.
O. Clearance of water line from other utilities. (New water lines constructed near sanitary
sewers and force mains).
1. New water lines parallel to sanitary sewers and force mains.
a. Locate water lines a minimum of 9 feet horizontally, outside wall to outside wall,
when parallel to sanitary sewers or force mains. Use the following procedure
when 9 feet of separation cannot be achieved:
(1) When a new water line is to parallel an existing sanitary force main or
gravity sanitary sewer and the 9 foot minimum separation distance cannot
be maintained, the existing sanitary sewer shall be replaced with lined
ductile iron or PVC pipe meeting ASTM specifications,having a minimum
working pressure rating of 150 psi or greater and equipped with pressure
type joints. The water lines and sanitary sewer shall be separated by a
minimum vertical distance of 2 feet, and a minimum horizontal distance of
4 feet, measured between the nearest outside walls of the pipe, and in all
cases, the water line shall be located above the sewer. When a water main
crosses a utility other than sanitary sewer, a minimum of 6 inches of
clearance must be maintained, and the water main shall have one joint of
pipe, a minimum 18 feet long, centered on the other utility.
b. Where a sanitary sewer crosses the water main, and that portion of the sewer
within 9 feet of the water is constructed as described in Section 290.44(e) of the
TCEQ Rules and Regulations, the water line may be placed no closer than 6
inches from the sewer. The separation distance must be measured between the
nearest outside pipe diameters. The water line shall be located at a higher
elevation than the sewer, wherever possible and one joint, a minimum of 18 feet
long, of the new pipe must be centered on the existing line.
2. When water lines are installed in areas which have existing sanitary sewers,
every effort should be made to maintain 9 feet of separation between the outside
pipe diameters of the two lines. Where this separation cannot be achieved
because of local conditions, which must be fully documented in any planning
material submitted,the following spaces shall be observed:
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Community Development Deparhnent WATER LINE DISTRIBUTION SYSTEM
a. Where a new water line is to cross or be installed in parallel with an existing
sanitary sewer, and the sewer is constructed as described in Section 290.44(e) of
the TCEQ Rules and Regulations, the separation distances specified in those
rules shall apply as though the sewer were new.
b. Where a new water line is to be installed in parallel to an existing clay, truss, or
concrete gravity sewer showing no evidence of leakage vertically and 4 feet
horizontally,the sanitary sewer need not be disturbed. Should excavation for the
water line produce evidence that the sewer is leaking, then the sewer must be
repaired.
c. Where a new water main is to cross an existing clay, truss, or concrete gravity
sewer showing no evidence of leakage, the sewer need not be disturbed if the
water line is to be installed at least 24 inches above the existing sewer. A full
joint of the water line, at least 18 feet long, should be centered over the sewer
crossing, in this case, so as to provide maximum protection against
contamination.
d. Existing clay, truss or concrete sewer pipe which shows no evidence of leakage
and because of physical limitations must remain at a higher elevation than the
proposed intersecting water line or closer than 2 feet may remain undisturbed if
the water line is inserted in a joint of pressure type encasement pipe at least 18
foot long and 2 nominal sizes larger than the water line. The encasement pipe
should be centered on the sewer crossing and both ends sealed with cement grout.
In lieu of this procedure, that portion of the sewer within 9 feet of the water line
may be replaced with cast iron or ductile iron pipe with water-tight joints as
described in Section 290.44(e)of the TCEQ Rules and Regulations, above.
3. Sanitary manholes -provide a minimum 9-foot horizontal clearance from outside
wall of existing or proposed manholes unless manholes and connecting sewers
can be made water tight and tested for no leakage. If a 9 foot clearance cannot be
obtained, the water line may be located closer to the inanhole when prior
approval has been obtained from the City of Friendswood by using one of the
procedures below; however, in no case shall the clearance be less than 4 feet.
a. Water line may be encased in a carrier pipe. Encasement shall be a steel water
line in a steel carrier pipe. Open cut and backfilled with cement stabilized sand
compacted backfill.
b. The water line may be augured past the manhole with one 20 foot section of C-
900 PVC pipe 150 psi, installed centered about the existing sanitary manhole
with pressure grout using a bentonite/clay mixture.
4. Fire hydrants. Do not install fire hydrants within 9 feet vertically or horizontally
of sanitary sewer mains, service leads, and force mains regardless of
construction.
1.05 APPURTENANCES
A. Valves.
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Community Development Deparhnent WATER LINE DISTRIBUTION SYSTEM
1. Set at maximum distances along line as follows:
a. Six inch (6")through fourteen inch(14")- 1000 feet.
b. Sixteen inch(16")through twenty inch(20")-2000 feet.
c. The total number of valves at any intersection shall equal the total
number of lines leading out from the intersection point minus one, three
(3) valves for a cross, and two (2) valves for a tee, unless otherwise
specified.
B. Valve Types
1. Valve types(all valves shall open counterclockwise and have mechanical
joints):
a. Six inch(6")through fourteen inch(14")—gate valves.
b. Sixteen inch(16")through twenty inch(20")—butterfly valves.
C. Location
1. All mains shall be valved within the street right-of-way. Valves shall not be
placed under or within 2 feet of ultimate pavement, except as specifically
approved by the City Engineer.
2. Valves are normally located on the projection of intersecting street right-of-way
lines or at the curb return adjoining a paved street across the main. Tapping
sleeves and valves are excluded from this requirement.
3. Isolate fire hydrants and flushing valves from the service line with a valve
located in the fire hydrant or flushing valve branch. This valve shall not be
located in the slope or flowline of ditches on roadside ditch roadways.
4. Intermediate valves, not located on the projection line of the right-of-way line,
shall be located on lot lines or 5 feet from fire hydrants but not set in driveways.
5. Locate valves a minimum of 9 feet horizontally from sanitary sewer crossings.
D. Fire hydrants and flushing valves.
1. Spacing.
a. Single Family Residential Development- 500 foot spacing.
b. Commercial, Multi-Family Developments and Multiple Single-Family
Dwellings-300 foot spacing and at all street intersections.
2. Location in or along street right-of-ways.
a. Fire hydrants shall be primarily located at street intersections where possible.
b. Locate fire hydrants at P.C.s of the intersection curb radius, 3 feet behind the
curb or projected future curb.
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City of Friendswood Design Criteria Manual
Community Development Deparhnent WATER LINE DISTRIBUTION SYSTEM
c. On all State highways and roadside ditch roadways, set the fire hydrants within
3 feet of right-of-way lines. Fire hydrants lead valves shall not be located in
the slopes or flowlines of ditches.
d. Set intennediate fire hydrants on lot lines, as extended to pavement, when
located between right of way intersections. These locations may be adjusted 5
feet either way to miss driveways or other obstructions. In either case, do not
locate fire hydrants closer than 3 feet from curbed driveways or 5 feet from
non-curbed driveways.
e. Fire hydrants and flushing valves shall not be installed within 9 feet of a
sanitary sewer system under any condition.
3. Location of fire hydrants or flushing valves outside the street right-of-way.
a. The City Fire Marshal will establish and approve the location of fire hydrants
and flushing valves in apartment complexes and platted private street
developments within the City.
b. Locate fire hydrants and flushing valves in protected, easily accessible areas
behind curb lines.
c. For fire hydrants ar flushing valves which are located adjacent to water lines
constructed in 10 foot wide waterline easements, the fire hydrant or flushing
valve shall be centered in a minimum 10'x10' separate easement.
d. For commercial and multi-family developments inside the City, provide
isolation valves at each end of fire loops requiring on-site fire hydrants.
4. Fire Flow
a. The basic fire flow fire hydrants must be able to maintain 3000-gpm for a 3-
hour period.
5. Fire hydrants should be audited and painted per City specifications.
E. Fittings
1. All fittings shall be identified and described on the construction plans.
2. Fittings are not permitted in fire hydrant leads, except as specifically approved by the
City of Friendswood.
3. Normally, all water main fittings shall be mechanical joints only. Push-on joints may
be used at special locations if specifically approved by the City of Friendswood.
4. All plugs shall be provided with retention clamps.
5. Polyethylene tube encasement shall conform with the minimum requirements of
"Polyethylene Encasement for Gray and Ductile Cast-Iron Piping for Water and
Other Liquids", ANSUAWWA C105, current revision. Soils within the project shall
be tested in accordance with Appendix A of ANSUAWWA C105 to adequately
detennine the requirements for encasement.
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City of Friendswood Design Criteria Manual
Community Development Department WATER LINE DISTRIBUTION SYSTEM
6. Concrete thrust blocking shall be required on all bends, tees, plugs and combinations
thereof.
7. All fittings and fire hydrants to be tied together with 3/4-inch stainless steel all-
threads and I-bolts or approved equal (ie Mega Lugs).
F. Water main service
1. Water main service for lines in or along street right-of-ways.
a. Meters 2 inch and smaller - located in rights-of-way, water line easements, or
in a minimum 5'x5' separate water meter easement. Meters shall be located in
areas with easy access and protection from traffic and adjacent to right-of-way
whenever possible.
b. Meters 3 inches and larger- located at the properiy line or in a minimum 10'x
20' separate water meter easement if necessary.
(1) Meters shall be located in areas with easy access and protection from
traffic and adjacent to rights-of-ways whenever possible.
(2) Meters shall not be located in areas enclosed by fences.
c. Separate tap and service leads shall be designed far each meter.
d. Meters larger than 2 inches must have bypass assembly and coupling for easy
change out. Contact the Deputy Director of Public Works for more details.
2. For proposed apartments or town homes in private street developments, provide one
master meter sized for the entire development. Exceptions may be granted by the
City of Friendswood for unusual circumstances. If an exception is approved, do not
interconnect multiple meters.
3. All sprinkler and irrigation lines must be equipped with a backflow prevention device
according to its application as required by TCEQ. The backflow assembly shall be
located after the meter for an irrigation system and in a vault near the building for a
sprinkler system. A certified tester shall test the backflow prevention assembly
annually and submit the results to the City.
1.06 SUBMITTALS
A. General-Conform to the following submittal requirements in addition to those of general
procedure of the City of Friendswood.
B. Water Line Sizes - Submit justification, calculations, and locations for proposed 6-inch
lines and for lines 12-inch and larger, for approval by the City of Friendswood, unless
sizes are provided by the City.
C. Valves - Submit information for approval by the City of Friendswood with justification
and locations for use of 16-inch and 20-inch gate valves proposed as substitutes for
butterfly valves.
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City of Friendswood Design Criteria Manual
Community Development Department WATER LINE DISTRIBUTION SYSTEM
D. Water Meter Service
1. Far construction inside city limits, submit an application far meter services and
metered sprinkler connections, to the Building Inspections Division, prior to
construction.
2. Submit requests for more than one service meter in proposed private street or
multi-family developments to the Department of Public Works.
E. Elevated stream or ditch crossings - Submit design calculations for support columns and
column spacing.
F. Master Development Plan - For multiple phase developments, submit a master
development plan.
G. Backflow Prevention — All irrigation and sprinklers must be equipped with backflow
prevention devices per TCEQ.
1. A double check backflow prevention assembly is required for 3" and larger lines.
1.07 QUALITY ASSURANCE
A. Prepare calculations and construction drawings under the supervision of a Professional
Engineer trained and licensed under the disciplines required by the drawings. The final
construction drawings must be sealed, signed, and dated by the Professional Engineer
responsible for the development of the drawings.
2.0 EXECUTION
2.01 RESEARCH REQUIREMENTS
A. Research existing utility and right-of-way information.
B. Verify that no restrictions exist that will deny approval of the project concept.
2.02 DESIGN ANALYSIS
A. Water line sizes - Prepare narrative justification and calculations for proposed 6-inch
lines and for lines 12-inch and larger, unless sizing is provided by the City of
Friendswood in advance.
B. Elevated stream or Ditch Crossings-Prepare design calculations far support columns and
column spacing.
2.03 DRAWINGS
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City of Friendswood Design Criteria Manual
Community Development Deparhnent WATER LINE DISTRIBUTION SYSTEM
A. General: Conform to the following drawing requirements in addition to those of
"Graphic Requirements" and the City's standard water line details and standard
specifications.
B. Appurtenances-Identify, describe and enclose in rectangular box on drawings.
1. Valves
a. Designate 6-inch through 12-inch gate valves with box as GV&B.
b. Provide complete description and size for other valves.
2. Water meters, service leads, and metered sprinkler connections.
a. Show the location of service line tees, tapping sleeve and valves, valve
boxes, and temporary plugs to be installed to serve future 3-inch or larger
meters.
b. Develop plan and profile sheets for 4-inch and larger leads and connections
that cross public rights-of-way or other utilities.
C. Construction features
1. Show all special construction features required to complete the project in a safe,
convenient and economical manner.
2. Auger Construction
a. If the construction is predominately open cut, all portions of the street that
must be augured shall be clearly shown on drawings by location and length.
Include designation for sections at trees with 6 inches or larger diameters
located within 10 feet of water Line.
b. Curbs - Include a requirement on drawings for construction of wheel chair
ramps at street intersections where curbs are to be removed or are damaged
by water line construction. Conform to the City's standards for ramps.
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City of Friendswood Design Criteria Manual
Community Development Department STREET PAVING
SECTION IV
STREET PAVING DESIGN REQUIREMENTS
1.0 GENERAL
1.01 CHAPTER INCLUDES:
Geometric design guidelines for streets, criteria for street paving, and standard paving notes for
drawing call outs.
1.02 REFERENCES
A. AASHTO-American Association of State Highway and Transportation Officials.
B. ASTM-American Society for Testing Materials.
C. ACI-American Concrete Institute.
D. T�UTCD-Texas Manual on Uniform Traffic Control Devices.
E. City of Friendswood Standard Details, latest version. These can be purchased from
Community Development ar downloaded from www.ci.friendswood.tX.us
1.03 DEFII�ITIONS
A. Geotechnical Engineer-An engineer certified by the American Association for Labaratory
Accreditation(A2LA).
B. HMAC-Hot Mix Asphaltic Concrete.
C. Curb and Gutter Sections - Full width concrete pavement with doweled on 4-inch by 12-
inch curbs. Curb and gutter sections require inlets and underground storm sewers.
D. Roadway ditch sections - Ditch sections adjacent to either full width reinforced concrete
pavement or asphaltic pavement. Roadside ditch sections do not require underground
storm sewers; however, the ditch sections must be designed to accommodate the storm
runoff.
1.04 DESIGN REQUIREMENTS
The following design requirements are applicable to all pavement within right-of-way limits
within the City of Friendswood.
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City of Friendswood Design Criteria Manual
Community Development Deparhnent STREET PAVING
A. General
1. All paving and construction plans shall be approved by the City of Friendswood for
all streets within the City.
2. Street design should confonn to all applicable planning tools, such as the Texas
Manual on Uniform Traffic Control Devices,major thoroughfare plans, master plans,
etc. Other considerations for design should include street function, street capacity,
service levels,traffic safety, pedestrian safety, and utility locations. These additional
considerations may effect the minimum requirements set forth herein. Refer to the
City of Friendswood Major Thoroughfare Plan.
3. Design shall conform to the City of Friendswood Standard Details.
B. Minimum Width Requirements and Paving:
1. Curb and Gutter sections for low-densiTy residential developments: 28 feet back to
back of curb(B/B).
2. Pavement for open-ditch sections for low-density residential developments: 26 feet
edge to edge of pavement.
3. Curb and gutter sections of inedium density residential, industrial, secondary and
collector streets: 41 feet BB of curb.
4. Pavement of major arterial thoroughfares: two divided traffic lanes of 25 feet(41ane
divided)or 34 feet B/B of curb(61ane divided).
C. Minimum Thickness and Reinforcement Requirements for Concrete Pavement:
The following requirements are the minimum allowable. Pavement thickness and
reinforcement shall be designed by the Professional Engineer responsible for the project
based on a current soils analysis and recommendations by a qualified geotechnical
engineer.
1. For pavement widths less than or equal to 28 feet B/B of curb:
a. Minimum concrete slab thickness shall be 6 inches with f� = 3,000 psi and
reinforcement shall be Grade 60, fy = 60,000 psi, #4 deformed reinforcing bars
spaced at 18 inches center to center both ways and minimum lap lengths of 18
inches. Expansion joints shall be placed at the end of each curb return and at a
m�imum spacing of 40 feet-6-inches.
b. Minimum stabilized subgrade thickness shall be 6 inches.
2. For pavement widths greater than 28 feet B/B and for major arterial
thoroughfares:
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City of Friendswood Design Criteria Manual
Community Development Department STREET PAVING
a. Minimum concrete slab thickness shall be 7 inches with f� = 3,000 psi and
reinforcement shall be Grade 60, f,, = 60,000 psi, #4 deformed reinforcing bars
spaced at 18 inches center to center both ways and minimum lap lengths of 18
inches. Expansion joints shall be placed at the end of each curb return and at a
maximum spacing of 40 feet- 6-inches on residential and collector streets, and
a maximum spacing of 60 feet — 6 inches on boulevards and major
thoroughfares.
b. Minimum stabilized subgrade thickness shall be 8 inches.
D. Subgrade Treatment: Geotechnical Engineer shall base depth of subgrade stabilization on
structural number (SN) in conjunction with pavement thickness design. Following is a
general guidance for subgrade treatment:
1. For subgrade soil conditions with a clay content of 10.0°/o or higher and plasticity
index (PI) of 10 or more, the subgrade shall be stabilized with lime. Subgrade shall
be stabilized with a minimum 6% lime by weight, at required thickness and
compacted to 95% standard proctor density. Alternative subgrade stabilization may
be substituted when specific recommendations are made by the geotechnical engineer
for the project, and when specifically approved by the City.
2. For subgrade soil conditions containing a clean sand with no clay content, the
subgrade shall be stabilized with cement.
E. Requirements for Intersections, Turnouts, Transitions, and Thoroughfares:
1. At a "T" intersection with a street that has not been improved to its ultimate width,
concrete pavement should be stopped either at the right-of-way line or the end of the
curb return,whichever would require less concrete removal at a future date.
2. For roadway turnouts placed at an existing street intersection, the turnout should be
designed to fit the ultimate pavement width of the intersecting cross street and then
transitioned to the existing roadway.
3. The usual transition length for meeting an open-ditch street is 50 feet for street
widths less than or equal to 28 feet B/B; 75 feet for 37 feet B/B width; and 100 feet
for 41 feet B/B width.
a. Streets other than concrete shall have transitions with a minimum thickness of
8 inches of lime stabilized subgrade, 6 inches of hot-mix asphaltic concrete
base, or approved equal,with 2 inches of hot-mix asphaltic surfacing.
b. Concrete streets shall have transitions with a minimum thickness of 6 inches of
stabilized subgrade and 6 inches of concrete pavement.
4. When paving only one roadway of a proposed two-roadway thoroughfare (boulevard
section) all left-turn lanes and esplanade crossovers shall be paved to the centerline of
the street right-of-way.
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City of Friendswood Design Criteria Manual
Community Development Department STREET PAVING
F. Requirements for Roadway Pavement with Open-Ditch Sections.
1. Minimum grade on ditches shall be 0.20 percent.
2. Ditch capacity shall be designed to handle runoff as determined by the City Drainage
Design Requirements.
3. The maximum side slope shall not exceed 3:1.
4. Culverts for roadside ditch only, shall be designed to carry ditch discharge, but not
less than 18-inch diameter pipe constructed of reinforced concrete.
5. The radius for cul-de-sac pavement shall be 40 feet if the cul-de-sac is located on the
interior of a residential subdivision and 600 feet or less in length. If the cul-de-sac
opens onto a thoroughfare or exceeds 600 feet in length,the pavement radius shall be
50 feet.
G. Requirements for Roadway Pavement with Curb and Gutter Sections:
1. Inlet spacing:
a. Curb inlets shall be spaced and sized to intercept the calculated runoff for the
design storm. The water surface elevation at the inlet shall be less than ar
equal to the top of curb for the design storm flow.
b. Maximum travel distance of water in the street to a curb inlet shall be 300 feet
on a major thoroughfare and in a commercial area. The maximum travel
distance of water in the street permitted in a single-family residential area shall
be 500 feet. Maximum drop of grade tangents from opposite directions to a
common inlet shall be 1.5 feet.
c. Curb inlets should be located on the intersecting side street at an intersection
with a major thoroughfare. Locations on the major thoroughfare at
intersections shall be specifically approved by the City.
d. Curb inlets shall have grate inlets lids.
e. Backfill around inlets with 1.5 sacks per cubic yard of cement stabilized and to
top of first stage inlets.
2. Minimum gutter gradient shall be 030 percent.
3. Maximum cut from finished grade at property line to top of curb shall be 1.75 feet.
4. The desired slope for driveways is 2% to 8%. A maximum slope of 10% may be
allowed with specific approval of the City.
5. Minimum grade shall be 1 percent fall around intersection turnout for a maximum
radius of 25 feet. Grades for larger radius shall be determined on an individual basis.
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City of Friendswood Design Criteria Manual
Community Development Deparhnent STREET PAVING
6. Vertical curves shall be installed when algebraic differences in grades exceed 1
percent. Elevations shall be shown at 10-foot intervals through vertical curves.
Maintain a minimum of 0.03-foot elevation change at 10-foot intervals by altering the
calculated elevations.
7. Radius of cul-de-sac pavement:
a. Residential (located within a residential development and not opening onto a
major thoroughfare)- 50 feet(measured to face of curb)
b. Commercial and residential that opens onto a major thoroughfare or is more than
600 feet in length- 50 feet(measured to face of curb)
8. When a curb and gutter intersects a drainage ditch, the grade of gutter shall be above
the designed water surface of the ditch.
9. Minimum gutter grade for cul-de-sac shall be 0.60 percent.
10. Majar tharoughfares shall be superelevated in accordance with AASHTO whenever
the centerline radius of the lanes or right-of-way are less than 2,000 feet.
11. The amount of cross slope over the pavement section should be shown on the
drawings. The usual cross slope is 3/8 inch per foot from curb line to quarter, and
1/4-inch per foot from quarter point to the center line, and 7/8-inch per foot for left-
turn lanes.
12. A minimum gradient of 0.40 percent around the longest radius is required on an L-
Type street intersection.
13. When meeting an existing curbed street, top of curb grades shall be designed to meet
an elevation 6 inches above the existing gutter. At existing inlets, top of curb grades
shall be designed to match existing top of curb elevations.
14. When the curb grades are not established below the natural ground, fill lines shall be
shown on the drawings and shall be of sufficient height to insure a minimum of 3/8-
inch per foot transverse slope toward the curb from the property line between a point,
2 feet outside the right-of-way and the top of curb. If this type fill is required and the
pavement is adjacent to a nonparticipating property owner, fill easements from this
properiy owner shall be obtained, filed,and a copy of the easements shall accompany
the final drawings. Construction of this nature will require back-slope drainage
design to prevent trapping storm runoff.
15. Grades should be labeled for all tops of curb. Centerline grades are acceptable for
open-ditch sections only.
H. Requireinents for Inlets with Curb and Gutter Sections:
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City of Friendswood Design Criteria Manual
Community Development Deparhnent STREET PAVING
1. Type "BB" with grate tops or type "H-2" inlets shall be used on all curb and gutter
sections within the City depending on runoff requirements, unless otherwise
approved by the City.
2. Inlets should be placed away from the inajor thoroughfare and on the side streets at
street intersections.
3. Attempt to keep the proposed inlets away from esplanade openings and out of major
thoroughfare intersections.
4. Inlets shall be placed at the end of pavement in order to eliminate drainage from the
pavement gutter into an open-ditch.
5. On open-ditch streets, place stubs with ring grates from inlets to ditches.
I. Requirements for Curbs and Sidewalks
1. Standard height is 4-inches and 12-inches wide for curb located along outside edges
of residential streets. Curb height for streets other than residential shall be 6 inches.
The curb height for all esplanades shall be 6-inches.
2. Sidewalk wheelchair ramps are required at all intersections and driveways. The
design and installation of such ramps shall comply with Texas Accessibility
Standards Architectural Barriers requirements.
3. All sidewalks are to be constructed in accordance with the City of Friendswood
Details. The design and installation of such sidewalks shall comply with Texas
Accessibility Standards Architectural Barriers requirements.
4. Sidewalks are required along all curb and gutter streets. The developer, prior to the
City's final acceptance of the infrastructure, must install sidewalks along reserves
and right-of-ways. When sidewalks are required, they shall have a width of not less
than 4-feet.
5. The location of all proposed and existing sidewalks shall be shown on the
construction drawings.
J. Requirements for Miscellaneous Items.
1. The type and amount of subgrade treatment shall be shown on the drawings.
2. Paving headers shall be placed at the end of all concrete pavements.
3. All concrete to be removed shall be saw cut before removal.
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City of Friendswood Design Criteria Manual
Community Development Deparhnent STREET PAVING
4. Sight distance requirements based on a design speed of 40 mph shall be used for
determining lengths of crest vertical curves for all pavements except boulevard
sections which shall be designed for 45 mph.
5. Standard City of Friendswood barricades shall be placed at the end of all dead-end
streets not terminating in a cul-de-sac.
6. The appropriate drainage agency approval must be obtained before City approval if
the design involves a GCCDD drainage way.
7. A letter of agreement approving the construction plan crossing is required when
paving is placed over a transmission pipeline.
8. When meeting existing concrete pavement, horizontal dowels shall be used if no
exposed reinforcing steel for interconnection with new pavement exists. Horizontal
dowels shall be Grade 60, #6 rebars, 24-inches long, drilled and embedded 12-inches
into the center of the existing slab and epoxied. Dowels shall be 18 inches center to
center, unless otherwise specified.
9. When concrete is removed for interconnections, the pavement shall be saw-cut, and
existing concrete removed,to expose a minimum of 15-inches of reinforcing steel. If
no reinforcing steel exists,use horizontal dowels as previously described.
10. Dead-end streets or ends of concrete slabs designed to be extended in the future shall
have paving headers and 15-inches of reinforcing steel exposed beyond the
pavement, coated with asphalt and wrapped with burlap or paving headers and dowel
type expansion joint for future pavement tie.
11. Pavement extensions shall connect to the existing pavement with a pavement
undercut and a minimum steel overlap of 1 S-inches.
12. Concrete pavement thickness design is required for all pavement within industrial
areas and on major thoroughfares. Concrete pavement thickness design shall be
based on AASHTO design procedures for rigid pavements.
13. The pavement structure for each roadway shall be designed based on soil data from
the site and based on the anticipated traffic volume, loading and service life of the
proposed pavement structure. The design engineer is responsible for ensuring that
the pavement structure is designed to withstand the anticipated loads that are
expected on the roadway.
14. Adjust manhole frames and covers within the limits of the pavement to meet the
proposed final top of slab.
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City of Friendswood Design Criteria Manual
Community Development Department STREET PAVING
15. Adjust manhole frames and covers outside the limits of the pavement to conform to
the final grading plan.
16. No more than one(1) shrinkage crack shall be allowed in each foriy(40)foot
header section. A shrinkage crack is defined as extending one half or more of the full
depth of the concrete(i.e. 3"or more on 6"thick concrete)appearing within 1 year of
the final concrete placement. If two(2)or more shrinkage cracks appear in a header,
the entire section shall be removed and replaced at contractor's expense.
17. If shrinkage cracks are less than one half of the depth of the concrete(i.e. less than 3"
on 6" thickness)then a recommendation letter and data sheets are required from the
testing laboratory as to the type of sealant which will be used to seal the shrinkage
cracks. This recommendation shall be approved by the City Engineer before
application of sealant.
18. Core samples for the sections will be taken no sooner than the twenty-eight(28)day
break of the original concrete pour sample.
1.05 APPURTENANCES—Reserved
1.06 SUBMITTALS—Reserved
1.07 QUALITY ASSURANCE.
A. All construction drawings and specifications shall be prepared by or under the supervision
of a currently Registered Professional Engineer of the State of Texas, and all documents
shall be sealed, dated, and signed by the engineer responsible for their preparation.
B. All geotechnical wark shall be performed by or under the supervision of a currently
Registered Professional Engineer of the State of Texas disciplined in the science of soil
analysis. All reports and documents shall be sealed, dated, and signed by the engineer
responsible for their preparation.
2.0 EXECUTION
2.01 RESEARCH REQUIREMENTS—Reserved
2.02 DESIGN ANALYSIS
A. All pavement design shall be supported by calculations to establish the required thickness
and reinforcement.
B. The current soils report shall be the basis for design considering the use, loading, and life
span of the proposed pavement.
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City of Friendswood Design Criteria Manual
Community Development Deparhnent STREET PAVING
C. Storm sewer inlets shall be established in such numbers and in such locations as to
effectively drain storm water from paved sections. A graphical plot and calculations of the
hydraulic gradient shall be furnished by the design engineer.
D. Open-ditch drainage shall be designed to accommodate the anticipated storm runoff, and all
culverts shall be designed to accommodate the expected ditch capacity. Construction
drawings shall indicate the direction of flow in the ditches, and profiles of the ditches shall
reflect this slope. Anticipated volumes of storm drainage shall be ideutified in each ditch to
enable future culverts to be sized to accommodate anticipated runoff.
2.03 DRAWINGS
A. Construction drawings shall be prepared in compliance with the City of Friendswood
Graphic Requirements.
B. Refer to "Geometric Design Guidelines for Subdivision Streets" for additional information
and guidance.
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City of Friendswood Design Criteria Manual
Community Development Department STORM DRAINAGE
SECTION V
STORM DRAINAGE DESIGN REQUIREMENTS
1.0 GENERAL
1.01 CHAPTER INCLUDES:
Criteria for the design of storm drainage improvements.
A. Design requirements - The drainage criteria administered by the City of Friendswood and
complemented by Galveston County Consolidated Drainage District and the Harris County
Flood Control District for newly designed areas provides protection from structural
flooding from a 100-year storm event. This is accomplished with the application of various
drainage enhancements such as storm sewers, roadside ditches, open channels, detention
and overland (sheet) runof£ The combined system is intended to prevent structural
flooding from extreme events up to a 100-year storm.
B. Street Drainage - Street ponding of short duration is anticipated and designed to contribute
to the overall drainage capability of the system. Storm sewers and roadside ditch conduits
are designed as a balance of capacity and economics. These conduits are designed to
convey less intense, more frequent rainfalls with the intent of allowing for traffic
movement during these events. When rainfall events exceed the capacity of storm sewer
system, the additional run-off is intended to be stored or conveyed overland in a manner
that reduces the threat of flooding to structures.
C. Flood Control - The City of Friendswood is a participant in the National Flood Insurance
Program. The intent of the flood insurance program is to make insurance available at low
cost by providing for measures that reduce the likelihood of structural flooding.
D. Relationship to the Platting Process - Approval of storm drainage is a part of the review
process for planning and platting of new development. The review of storm drainage is
conducted by the Community Development Department.
1.02 REFERENCES
A. City of Friendswood Standard Details, latest version. These can be purchased from
Community Development or downloaded from www.ci.friendswood.tx.us
B. City of Friendswood Flood Damage Prevention Ordinance 87-10 and subsequent revisions.
C. Galveston County Consolidated Drainage District Criteria Manual
D. Harris County Flood Control District Design Criteria ManuaL
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City of Friendswood Design Criteria Manual
Community Development Deparhnent STORM DRAINAGE
E. TX DOT Bridge Division Hydraulic Manual, Third Edition, 1985.
F. National Weather Service Documents - TP-40 Rainfall Frequency Atlas of the United
States.
1.03 DEFINITIONS
Conduit-any open or closed device for conveying flowing water.
Drainage Area Map - Area map of watershed which is subdivided to show each area served by
each subsystem.
FEMA-Federal Emergency Management Agency
GCCDD- Galveston County Consolidated Drainage District
HCFCD-Harris County Flood Control District
Hydraulic Grade Line - A line representing the pressure head available at any given point within
the drainage system.
In-Fill Development - Development of open tracts of land in areas where the storm drainage
infrastructure is already in place and takes advantage of the existing infrastructure as a drainage
outlet.
Public storm sewers - Defined as sewers and appurtenances that provide drainage for a public
right-of-way, or more than one private tract, and are located in public right-of-way or easement.
Private storm sewers provide internal drainage for a reserve or other tract. Private storm sewer
connections to public storm sewers shall occur at a manhole or at the back of an inlet as approved
by the City. All private storm sewers shall be constructed in conformance with these standards.
Rainfall frequency- Probability of a rainfall event of defined characteristics occurring in any
given year. Information on rainfall frequency is published by the National Weather Service. For
the purpose of storm drainage design,the following frequencies are applicable:
1. 5-year frequency— a rainfall intensity having a 20 percent probability of occurrence
in any given year, or nominally likely to occur once every 5 years.
2. 10-year frequency—a rainfall intensity having a 10 percent probability of occurrence
in any given year, or nominally likely to occur once every 10 years.
3. 25-year frequency— a rainfall intensity having a 4 percent probability of occurrence
in any given year, or nominally likely to occur every 25 years.
4. 100-year frequency- a rainfall intensity having a 1 percent probability of occurrence
in any given year, or nominally likely to occur every 100 years.
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Redevelopment - A change in land use that alters the impervious cover from one type of
development of either the same type or another type, and takes advantage of the existing
infrastructure in place as a drainage outlet.
Sheet Flow- Overland storm run-off that is not conveyed in a defined conduit, and is typically in
excess of the capacity of the conduit.
1.04 DESIGN REQUIREMENTS
All designs of drainage facilities should meet the requirements of the City of Friendswood Standard
Specifications and Standard Drawings.
A. Determination of Run-off
1. Design Storm Events - All drainage improvements shall be designed for the
following storm frequencies:
Type of Facility
Road Side Ditch 5 years
Storm Sewers 5 years
Channels/Storm Sewers/Culverts draining 100 acres or less 25 years
Bridges 100 years
Creeks/Channels/Culverts draining 100 acres or more 100 years
2. The Rational Method shall be used for determining the peak flow rate in the sizing of
all drainage improvements.
a. Time of Concentration (minutes) is the time required for peak runoff from the
entire upstream contributing area to reach the point of interest. Time of
concentration can be calculated based upon an analysis of the actual travel time
from the most remote point in the drainage area. The travel path should be
clearly denoted and a sketch included in the design calculations.
to = D/60V+ 10 (minutes)
D = flow distance(ft)
V = flow velocity(ft/sec)
For purposes of calculating t�,the following velocities are recommended:
V= 1 ft/sec for overland flow
V= 1.5 ft/sec or flow across paved surfaces or along gutter flowlines.
V= 2 ft/sec for flow in ditch or channel
V= 3 ft/sec for flow in storm sewer
b. Rainfall Intensity(inches/hour)shall be calculated using the following formula:
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Coirununity Development Department STORM DRAINAGE
I = b
(d+t�)e
Values typically used in Friendswood are listed below:
Rainfall
<=60 min FrequencX b d e
5-year 92.9 19.7 0.788
10-year 107.9 23.6 0.781
25-year 98.5 24.0 0.729
100-year 90.8 16.5 0.685
Rainfall
>60 min Frequenc� b d e
5-year 70.1 7.7 0.752
10-year 96.6 17.2 0.770
25-year 89.2 10.4 0.736
100-year 84.0 11.0 0.679
b, d, and e values are derived from a single frequency rainfall intensity graph.
b=the y-intercept of the straight line
d=a constant used to adjust the relationship to plot as a straight line
e=the slope of the straight line
c. The Rational Method is a method for calculating the peak run-off for a storm
drain system. The formula for determining the peak flow rate is:
Q=CfCIA
Where:
Q = Flow rate(cubic feet per second(cfs))
Cf= Frequency factar,the product of Cf and C should not exceed 1.0
C= Runoff Coefficient
I = Rainfall intensity (inches/hour)for a given storm frequency
(Typically 5 year, 25 year and 100 year).
A= Area(acres)
Far the purposes of calculating the frequency factor "Cf" use the following
values:
Cf= 1.00, far storm frequencies of 10 years or less
Cf= 1.10, for storm frequencies of 25 years
Cf= 1.25, for storm frequencies of 100 years
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For the purposes of calculating the run-off coefficient "C" use the following
values:
Land Use Type Run-off Coefficient
Raw Undeveloped Acres 0.20
Improved Undeveloped Acres 030
(i.e.mowed, filled,re-graded, etc.)
Park Land 0.40
Residential:
SFR-Estates 0.45
SFR 0.55
Multi-family
MFR-GHD 0.65
MFR-L 0.75
MFR-M 0.80
MFR-H 0.85
MHR 0.85
Commercial/Industrial
OPDBP 0.90
OBD/CSC/NC 0.95
LUI 0.95
Pond(detention and amenity) 1.00
Alternatively, for estate-sized lots (2+ acres), the run-off coefficient "C" in the
rational method formula can be calculated from the equation:
C=0.6Ia+0.2
Where: C=watershed coefficient
Ia= impervious area/total area
If the alternate form is to be submitted,the calculation of C shall be provided as
part of the drainage calculations.
B. Design of storm sewers
1. Design Frequency
a. Newly Developed Areas
The design storm event for sizing storm sewers in newly developing areas will
be a 5-year rainfall. In the case where new development will interfere with the
natural sheet flow of the land, the storm system must accommodate the runoff.
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Runoff should not be allowed to run over newly developed lots or streets. Stub
out streets next to underdeveloped areas are to stub out storm lines to the limits
of the streets.
b. Redevelopment or In-fill Development
The existing storm drain will be evaluated using a 5-year storm, assuming no
development takes place. The storm drain will be evaluated with the
development in place.
(1) If the proposed redevelopment has a lower or equal impervious cover,no
modifications to the existing storm drain are required.
(2) If the hydraulic gradient of the existing storm drain is below the top of
the curb,no improvements to the existing storm drain are required.
c. Private Drainage Systems
Storm sewers for private drainage systems should conform to the City of
Friendswood Standards for public drainage systems.
(1) An approved development permit must be filed with the City of
Friendswood before any work shall be done on a private drainage
system. Part of the development permit include a plan and profile sheets
detailing the scope of the work including elevations.
(2) Open ditch areas may be converted into storm sewer lines with the
approval of a development permit. Guidelines for the process are
available at the City of Friendswood Community Development Division.
2. Velocity Considerations
a. All stonn drains shall be designed by the application of Manning's Equation and
the Continuity Equation.
Manning's Equation:
V=(1.486/n)RZi3Sv2
Where V= velocity(ft/sec)
R= hydraulic radius(area in square feet/wetted perimeter in feet)
S = slope of energy line in feet/feet(same as conduit bottom slopes for
uniform flow)
n= coefficient of roughness
n=0.013 for concrete pipes,
n=0.024 for CMP
n=0.011 forPVC
n=0.010 for HDPE
*NOte: All public storm sewers must be constructed of RCP. Manning's roughness coefficients for
CMP, PVC, and HDPE are to be used for private storm sewers only. All storm sewer pipe
entering City of Friendswood ROW shall be RCP.
Continuity Equation:
Q = VA
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Community Development Department STORM DRAINAGE
Where Q= discharge(cfs)
V=velocity(ft/sec)
A =cross sectional area of conduit(AZ)
b. Design velocities shall be 3 feet per second with the pipe flowing full.
c. Maximum velocities should not exceed 7 feet per second.
d. Minimum Storm Sewer Pipe Slopes:
Pipe Diameter % Slope
18 0.26
24 0.18
30 0.14
36 0.11
42 0.08
48 0.07
54 0.06
60 0.05
For pipe sizes not listed above,the minimum slope should be determined
utilizing a design velocity of 3 fps.
3. Pipe Sizes and Placement
a. Use the storm sewer and inlet leads with at least 24-inch inside diameter or
equivalent cross section. Box culverts shall be at least 2 feet x 2 feet. Closed
conduits: circular, elliptical, or box, shall be selected based on hydraulic
principals and economy of size and shape.
b. Larger pipes upstream should not flow into smaller pipes downstream unless
construction constraints prohibit the use of a larger pipe downstream, or the
improvements are outfalling into an existing system, or the upstream system is
intended for use in detention.
c. Match crowns of pipe at any size change unless severe depth constraints
prohibit.
d. Locate storm sewers in public street rights-of-way or in parallel and adjoining
easements or in approved easements. Easements must be at least 20-feet wide
and the storm sewer must be centered in the easement. Side and back lot
easements are discouraged.
e. Follow the alignment of the right-of-way or easement when designing cast in
place concrete storm sewers.
£ A straight line shall be used for inlet leads and storm sewers.
g. Center culverts in side lot storm sewer easeinents.
h. Storm boxes may substitute for pipes when workable space is an issue. The
City of Friendswood must approve each case on an individual basis
4. Starting Water Surface and Hydraulic Gradient
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a. The hydraulic gradient shall be calculated assuming the top of the outfall pipe
as the starting water surface.
b. At drops in pipe flowline, should the upstream pipe be higher than the
hydraulic grade line, then the hydraulic grade line shall be recalculated
assuming the starting water surface to be at the top of pipe at that point.
c. For the design storm, the hydraulic gradient shall at all times be below the
gutter line for all newly developed areas.
d. Hydraulic grade lines shall be shown on all profile drawings.
5. Manhole Locations
Use manholes for precast conduits at the following locations:
a. Size or cross section changes.
b. Inlet lead and conduit intersections.
c. Changes in pipe grade.
d. Street intersections.
e. A maximum spacing of 500 feet measured along the conduit run.
£ Manholes shall be placed so as not to be located in the driveway area.
6. Inlets
a. Locate inlets at all low points in gutter.
b. Valley gutters across intersections are not permitted.
c. Inlet spacing is generally a function of gutter slope. For minimum gutter
slopes,the maximum spacing of inlets shall result from a gutter run of 500 feet
from high point in pavement or the adjacent inlet on a continuously graded
street section, with a maximum of 1000 feet of pavement draining towards any
one inlet location.
d. Use only Standard Inlets:
Inlet Application Capacity
Type A Parking Lots/Small Areas 2.5 cfs
Type B-B Residential 5.0 cfs
Type D Parking Lots 2.0 cfs
Type E Roadside ditches 20.0 cfs
Type H-2 Residential/Commercial 5.0 cfs
e. Do not use "Beehive" grate inlets or other"specialty" inlets.
f. Do not use grate top inlets in unlined roadside ditch.
g. Place inlets at the end of the proposed pavement, if drainage will enter or leave
pavement.
h. Do not locate inlets adjacent to esplanade openings.
i. Place inlets on side streets intersecting major streets, unless special conditions
warrant otherwise.
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Community Development Deparhnent STORM DRATNAGE
C. Consideration of Overland Flow
1. Design Frequency. The design frequency for consideration of overland sheet
flow shall consider extreme storm events which exceed the capacity of the
underground storm sewer system resulting in ponding and overland sheet flow
through the development to the primary outlet.
2. Relationship of Structure to Street. All structures shall be constructed according to
the Flood Damage Prevention Ordinance and should be higher than the highest level
of ponding anticipated from the extreme event analysis.
3. Calculation of Flow.
a. Streets will be designed so that consecutive high points in the street will
provide for a gravity flow of drainage to the ultimate outlet.
b. The maximum depth of ponding at high points will be the top of curb or the
centerline of roads without curb.
c. The maxiinum depth of ponding at low points will be 10-inches above the
top of curb or the centerline of roads without curb.
d. Sheet flow between lots can be provided only through a defined drainage
easement.
e. A map shall be provided to delineate extreme event flow direction through a
proposed development and how this flow is discharged to the primary drainage
outlet.
£ In areas where ponding occurs and no sheet flow path exists,then a calculation
showing that run-off from the 100-year event can be conveyed and remain in
compliance with the other terms of this section must be provided.
4. Overland Flow shall enter outfall drainage facilities (channels or detention pond)
through a storm sewer sized to convey the 100-year event. Calculations shall be
submitted far sizing the structure and determining that adequate inlet capacity exists.
D. Design of Open Channels
1. Design Frequency
a. Open channels shall be designed according to methods described in the
GCCDD&HCFCD Criteria Manuals.
b. Design standards for channel construction should follow the requirements
specified in the GCCDD&HCFCD Criteria Manuals.
c. Design standards for the outfalls into channels should conform to those in the
GCCDD&HCFCD Criteria Manuals.
2. Determination of Water Surface Elevation.
a. Water surface elevations shall be calculated using Manning's Equation and the
Continuity equation.
b. For the design storm event, the water surface should be calculated to remain
within banks and below freeboard.
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3. Design of Culverts
a. Head losses in culverts shall conform to T�OT Bridge Division Hydraulics
Manual, Chapter 4 - Culverts.
b. Generally, corrugated metal pipe will not be approved for pennanent
installation of culverts in City right-of-way.
E. Design of Roadside Ditches
1. Design Frequency
a. Roadside ditch design is permissible only for single-family residential lots
having widths larger than, or equal to, 120 feet.
b. The design storm event for the roadside ditch shall be to 0.5 feet below the
edge of pavement or the natural ground at the right-of-way line, whichever is
lower.
c. Design capacity for a roadside ditch shall be to 0.5 feet below the edge of
pavement or the natural ground at the right-of-way line,whichever is lower.
d. The design must include an extreme event analysis to indicate that structures
will not be flooded.
2. Velocity Considerations
a. For grass-lined sections,the design velocity shall be 2.0 feet per second during
the design event. The maximum velocity shall be 5 fps.
b. A grass lined or unimproved roadside ditch shall have side slopes no steeper
than three horizontal to one vertical.
c. Minimum grades for roadside ditches shall be 0.2-foot per 100-foot.
d. Calculation of velocity will use a Manning's roughness coefficient of 0.040 for
earthen sections and 0.025 far ditches with paved inverts.
e. Use erosion control methods acceptable to the City when design velocities are
expected to be greater than 3 feet per second.
3. Culverts
a. Culverts will be placed at all driveway and roadway crossings, and other
locations where appropriate.
b: Culverts will be designed assuming inlet control.
c. Roadside culverts are to be sized based on drainage area. Calculations are to
be provided for each block based on drainage design criteria presented in this
manual.
d. Cross open channels with roadside culverts no smaller than 18 inches in
diameter or equivalent. The size of culvert used shall not create a head loss of
more than 0.20 feet greater than the normal water surface profile without the
culvert.
e. Use erosion control methods acceptable to the City when design velocities are
expected to be greater than 3 feet per second.
f. Sloped end treatments(S.E.T.)must be placed at all driveways. If S.E.T.'s
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Coirununity Development Department STORM DRAINAGE
cannot be used due to space constraints, the culvert must be extended 12" on
each side of the driveway. A head wall may be used to replace the extension
of the culverts. Contact the Community Development Division for details.
4. Depth and Size Limitations
a. Residential streets - the maximum depth will not exceed 2.5 feet from edge of
pavement.
b. Roadside ditch bottoms should be at least 2 feet wide.
c. Ditches in adjoining and parallel easements shall have the top of bank not less
than 2 feet from the outside easement line.
d. Roadside ditch side slopes shall not exceed 3 horizontal to 1 vertical.
F. Design of Outfalls.
1. Outfall design shall conform to GCCDD and HCFCD standards.
2. Detention pond and storm sewer outfalls shall be placed one foot above the flowline
of the receiving channels, creeks and detention pond, or two foot above normal water
elevation,whichever is greater.
3. Outfalls shall be placed 6 inches above the flowline of the receiving roadside ditch.
G. Storm Water Detention
The purpose of storm water detention is to mitigate the effect of new development on
an existing drainage system. If 10% or less of the entire property (new SFR lot, not
subdivision) will be affected by new impervious cover, then a new or revised
drainage plan will not be required.
1. Application of Detention.
a. As a normal consideration, storm water detention is required. The use of on-
site detention is required in order to mitigate potential damage to existing
structures unless the current infrastructure is improved, or the City has
developed a plan for a detention facility to serve the overall area.
b. Design calculations for sizing the detention basin and related structures must be
performed by the applicable method described in the following sections.
c. All calculations shall be sealed and signed by a Registered Professional
Engineer.
d. A parking lot may be used as part of the detention system, provided that the
maximum depth of water over the inlet does not exceed nine (9") inches and
the maximum depth in the parking stall does not exceed six(6") inches.
e. The Rational Method can be used far determining the peak release rate and the
peak inflow rate for a detention pond.
2. Calculation of Detention Volume
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Community Development Deparnnent STORM DRAINAGE
a. The Modified Rational Method may be used to determine the detention storage
volume for developments that are 5 acres or smaller.
b. A simplified method may be used for determining the amount of detention
volume required based upon a rate of 0.45 acre-feet/acre, as found in the
GCCDD Criteria Manual. This method may be used for developinents less
than 10 acres.
c. The Triangular Hydrograph method may be used for determining the amount of
detention volume required for development of 100 acres or less.
d. The Unit Hydrograph Method, which calculates the required detention storage
volume by determining the difference in volumes between the inflow and
outflow hydrographs,may be used for developments less than 100 acres.
e. For developments with more than 100 acres, a detailed hydrologic analysis
utilizing the HEC-1 Flood Hydrograph method will be required.
3. Calculation of Outlet Size
Outfalls which utilize a pipe restrictor to control outflow shall use the orifice
equation.
a. Reducer or Restrictor Pipes shall be sized as follows:
(1) Use the following equations to calculate the required outflow orifice:
Area of pipe=�d2/4
Q=CA(2 gh)�'
D=Ql�z /2.25 h-lia
Where Q=outflow discharge in cfs.
C =0.8
h=water surface differential (ft)
D=arifice diameter(ft)
A=area of pipe(ft2)
g=gravity(32.2 ft/s2)
(2) For head differential in systems outfalling into a roadside ditch or storm
sewer use actual head loss or 1-foot whichever is greater. For all other
discharge conditions use 2 feet or difference of 100 year water surface
elevation and elevation of 25 year storm in receiving channel, whichever
is greater.
(3) For detention systems outfalling into a public storm sewer, the restrictor
shall be sized based upon the peak 5-year developed flow.
(4) For detention systems outfalling into a public roadside ditch, the
restrictor shall be sized based upon the peak 5-year undeveloped flow.
(5) For detention systems outfalling into creeks, channels or storm sewers
sized to carry the 25-year or 100-year storm, the restrictor shall be
metered to release the 5-year, 25-year and 100-year undeveloped flows.
(6) Restrictor shall be either the required diameter or the equivalent cross-
sectional area. The orifice diameter"D" shall be a minimum of 6 inches.
(7) Detention ponds less than one (1) acre in size shall have a minimum of 4
inches of freeboard. All ponds one (1) acre or larger in size shall have at
least one (1') foot of freeboard. Freeboard shall be measured from the
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Community Development Depariment STORM DRAINAGE
maximum 100-year water surface elevation and shall not be used in the
calculation of storage or mitigation.
4. Detention Pond Structural Requirements
a. Side slopes shall not exceed a slope of 4 horizontally to 1 vertically.
b. Ponds with lengths over 50 feet shall have a concrete pilot channel.
c. Concrete pilot channels shall have a minimum width of 4 feet and a minimum
thickness of 4 inches with #3 rebar spaced at 12 inches on center each way.
The concrete channels shall be constructed of 5-sack cement concrete with a
compressive strength of 2500 psi at 28 days. Provide a 1-inch depression per
every 1-foot of transverse slope with redwood headers spaced every 40 feet.
d. Appropriate covering (grass, slope paving, etc.) shall be established on side
slopes and pond bottom to prevent erosion during periods of maximum water
velocity
e. A concrete gravity spillway, set at the maximum ponding elevation, shall be
provided at the detention pond outfall structure.
£ Wet detention ponds and ponds with vertical walls shall provide access for
safety and maintenance purposes. Wet detention systems shall have a method
in-place to minimize stagnation, such as an aeration system.
g. "Dry"detention ponds shall not be designed with less than two feet of depth.
5. Ownership and Easements
a. Private Facilities
(1) Pump systems shall not be allowed. Only detention facilities which rely
on gravity to discharge storm runoff will be allowed by the City.
(2) Responsibility for maintenance of the detention facility must be indicated
on the plat.
(3) All private properties being served shall have drainage access to
the pond.
(4) A private maintenance agreement must be provided when multiple tracts
are being served.
b. Public Facilities
(1) Facilities will only be accepted for maintenance by the City in cases
where public drainage is being provided.
(2) The City will require a maintenance work area 20-foot wide surrounding
the extent of the detention area. Public rights-of-way or permanent
access easements may be included as a portion of this 20-foot width.
(3) A dedication of easement or reserve must be provided by plat.
(4) Proper dedication of public access to the detention pond must be shown
on the plat or by separate instrument. This includes permanent access
easements with overlapping public utility easements.
6. Off-Site Detention
Off-site detention, such as regional or sub-regional detention, may be used provided:
a. The detention facility is in the same watershed ar sub-watershed as the
developer's site.
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b. The development is less than or equal to 8 acres for any single-family
residential development or less than or equal to 5 acres for any other type of
development.
c. Excess detention capacity may not be used for mitigation of fill in the flood
plain.
d. The Developer provides conveyance to the detention facility without having a
detriinental effect on any adjacent properties.
e. If conveyance is directed through properties not directly owned by the
developer, an executed contract ar recorded deed between the parties agreeing
to the said conveyance must be presented to the board.
f. This procedure is approved by both the City and the corresponding drainage
entity(GCCDD or HCFD) during preliminary plan review.
g. Regional Detention. It is the desire of the City of Friendswood that regional
detention be utilized when available. If new development is within the service
area of a publicly owned ar operated regional storm water detention facility,
connection to such regional facility shall be as required by the drainage master
plan applicable to such facility.
7. Redevelopment and Additions
a. Additional impervious cover may be added to a single-family residential lot(1-
time allowance), provided that the cumulative increase in impervious cover
does not exceed 10% of the original impervious cover for that lot.
b. A drainage plan and detention calculations will be required for any proposed
improvements, additions, or redevelopment in excess of the 10% impervious
cover allotment.
c. All commercial and non-residential new developments, additions, or
redevelopment will require a new or revised drainage plan for additional
impervious cover.
1.05 RESERVED
1.06 SUBMITTALS
A. Preliminary Submittals- Submit for Review and Comment
1. One line drawings are recommended and may be required as part of the platting
process. One line drawings should include:
a. Approximate definition of lots and street patterns.
b. The approximate drainage areas for each system.
c. A definition of the proposed drainage system by single line.
d. The proposed pipe diameters.
e. Any proposed drainage easements.
£ Floodplain boundary, if any.
B. Final Design- Submit the Following far Approval.
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1. Copies of any documents which show approval of exceptions to the City design
criteria.
2. Design calculations for storm line sizes and grades, and for detention facilities, if
any.
3. Design calculations for the hydraulic grade line of each line or ditch, and for
detention facilities, if any.
4. Contour map and drainage area map of the project.
5. Plan and profile sbeets showing storm water design(public facilities only).
6. Projects located within a Flood Plain boundary or within a Flood Plain Management
area shall:
a. Show the Flood Plain boundary or Flood Plain area, as appropriate, on the one-
line drawing or drainage area map.
7. Soil boring logs.
8. All drainage plans shall have a current FEMA flood zone determination statement.
C. Signature State- Submit the Following for Approval.
1. Review prints.
2. Original drawings.
3. Storm water detention maintenance agreement letters.
1.07 QUALITY ASSURANCE
A. Prepare calculations and construction drawings under the supervision of a Professional
Engineer trained and licensed under the disciplines required by the drawings. The final
construction drawings and all design calculations must be sealed, signed, and dated by the
Professional Engineer responsible for the development of the drawings.
PART 2 EXECUTION
2.01 RESEARCH REQUIREMENTS—Reserved
2.02 DESIGN ANALYSIS
A. All projects shall be tied to National Geodetic Survey (NGS) Datum adjustment which
matches the Federal Emergency Management Agency (FEMA) rate maps or the most
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current NGVD which matches the FEMA rate maps. In the event GPS surveying is used to
establish benchmarks, at least two references to benchmarks relating to the FEMA rate
maps must be identified. Equations may be used to translate other datum adjustments to
the required adjustment.
B. Plan sets will include a drainage area map, which shall contain all storm sewer drainage
calculations as determined by the Rational Method.
C. All drainage systems for curb and gutter pavements shall be underground closed conduits;
individual residential lot drainage is exempt. Drainage systems for pavements without curb
and gutter shall be roadside open-ditch sections.
D. Soil boring with logs shall be made along the alignment of all storm sewers having a cross
section equal to or greater than 72 inches in diameter or equivalent cross section area.
Boring should be taken at intervals not to exceed SOO linear feet and to a depth not less than
3 feet below the flow line of the sewer. The required bedding will be determined from the
soil boring.
E. Plan sets shall include the 5-year Hydraulic Grade Line for storm sewers and roadside
ditches on the plan and profile sheets.
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Community Development Department SITE DEVELOPMENT
SECTION VI
SITE DEVELOPMENT
1.0 GENERAL
1 A 1 CHAPTER INCLUDES:
Site Development
1.02 REFERENCES
A. City of Friendswood Zoning Ordinance.
B. City of Friendswood Subdivision Ordinance.
C. City of Friendswood Standard Details, latest version. These details can be purchased from
Community Development or downloaded from www.ci.friendswood.�.us
1.03 DEFINITIONS
A. Commission—Planning and Zoning Commission
1.04 DESIGN REQUIREMENTS
A. Site Development Requirements
1. General Requirements
a. Site development plans for all site developments within the City of
Friendswood shall be approved by the City prior to construction.
b. Site developments, not including single family residential, shall include any
project that affects public water, wastewater, storm drainage, or paving
facilities.
c. All site developments shall conform to the requirements of these Standards,the
2003 International Code, and applicable rules and regulations of the City of
Friendswood.
d. All wastewater, drainage and paving site development improvements shall be
privately owned, operated and maintained up to and including the connection
to the public system. All water site development improvements shall be
privately owned, operated and maintained up to, but not including, the meter
and meter vault.
e. Restore the City of Friendswood ROW to existing or better condition.
f. Private utilities and service lines shall be placed in an easement or on the
property being served.
2. Design Review Requirements far Site Development Plans.
Revised 9/11/2006 Section VI Page 1 of 9
City of Friendswood Design Criteria Manual
Coirununity Development Deparhnent SITE DEVELOPMENT
a. All site development plans for proposed developments shall be submitted to the
City for approval prior to construction. Site development plans shall show all
proposed water, wastewater, paving, parking, drainage, street signage, streetlight
locations, flood protection facilities, and sidewalks with approved ADA ramps
locations
b. A traffic impact study shall be required for any development proposal expected
to generate traffic volumes that will significantly impact the capacity and/or
safety of the street system. All proposed developments generating volumes of
5,000 trips per day or greater shall meet this criteria. The trip estimate shall be
based on the latest version of the Institute of Transportation Engineers, Trip
Generation Manual.
c. The developer should first schedule a Development Review Committee meeting
with community development staf£ At this meeting, the developer should be
able to discuss infrastructure issues and the feasibility of developing the site.
d. The next step is to prepare a site plan submittal to be reviewed by staf£ The
developer shall consult with staff until all significant issues surrounding the
proposed site plan and development are resolved, prior to proceeding to the
Commission.
e. The final site plan is prepared after all comments on staff review have been
addressed. Any applicant may submit a site plan for consideration by the
Comn7ission at any time aftet• the staff review is completed. The Planning and
Zoning Commission reviews the final document for cornpleteness and public
awareness. The submittal for the final site plan requires that 9 copies of:
1. Site Plan
2. Landscaping Plan
3. Elevation Plan
And 3 copies of:
1. Drainage Plan
2. Utility Plan
3. Grading Plan
4. Photometric Plan
5. Storm Water Pollution Prevention Plan
To be provided to department staff at least 3 days prior to the next regularly
scheduled Planning and Zoning meeting.
£ Approval from the appropriate drainage agency is required prior to Commission
approval. Once the site plan is approved, the developer may begin the building
permitting process.
g. Three(3) copies of the site development plans shall be submitted to the Building
Official for review. The City will Typically respond within 2 to 4 weeks of the
initial submittal.
h. When plan changes are requested, 2 copies of the revised site development plans
shall be resubmitted to the City for final review and should result in the issuance
of the building pennit.
3. Building Slab Elevations - Minimum building slab elevations shall conform to tl�e
requirements of the City of Friendswood Flood Damage Prevention Ordinance.
Revised 9/11/2006 Section VI Page 2 of 9
City of Friendswood Design Criteria Manual
Community Development Deparhnent SITE DEVELOPMENT
4. Water Service - Water service lines and meters shall be sized in accordance with
requirements set out in the Waterline Distribution System Design Requirements.
5. Sanitary Sewer Service - Sanitary sewer service leads are normally installed during
construction of the public sanitary sewer. When a sanitary sewer service lead is to be
installed for a site development, refer to the Wastewater Collection System Design
Requirements. All lots, tracts, or reserves shall be connected directly to a public
sanitary sewer by a single lead, except as specifically approved by the City. The City
shall be contacted for all sanitary sewer connections for commercial projects within
the City.
6. Site Drainage Requirements - All commercial, industrial, office, recreational, and
multi-family tracts shall have an internal drainage system. The internal drainage
system shall connect all site runoff into a storm sewer system that shall connect to the
public drainage facilities in the area, except with specific approval.
a. The internal site storm sewer shall be connected to a public storm sewer and a
manhole ar at an inlet adjoining the site. The site drainage outfall shall be
connected to the nearest existing drainage system with adequate capacity to
serve the drainage area. Where extension of the existing drainage system is
required, all costs for extension shall be the responsibility of the developinent.
b. All internal facilities shall be designed by a Registered Professional Engineer
and shall be sized to drain the site in accordance with these standards.
c. Drainage calculations shall be submitted with all site development plans.
Other supporting data may be required by the City.
d. When the site drains directly into a Galveston County or Harris County facility
and/or into a highway right-of-way, the appropriate governmental entity
(entities) shall approve the site development connection to public facilities.
7. Driveways
a. It is desirable to minimize the number of non-residential driveways on all
streets in order to reduce the number of conflict points and facilitate traffic
flow. It is recognized, however, that certain existing tracts may not be able to
fully comply with the following standards due to limited frontage or other
constraints.
b. When compliance with these criteria is precluded due to the location of
driveways on adjoining properties, attempts should be made to obtain
alternative access where feasible, including joint access driveways, access
easements to adjoining properties or access to intersecting streets.
c. If it can be demonstrated to the City Engineer that sufficient attempts to secure
alternative access have been made and that such access is still not possible,the
City Engineer may accept a Traffic Impact Analysis performed by a Registered
Professional Engineer to permit a deviation to the driveway spacing
requirements indicated herein.
d. Residential driveways shall be a minimum of 12 feet wide at the right-of-way
line and should be placed 25 feet away from the properiy line.
Revised 9/11/2006 Section VI Page 3 of 9
City of Friendswood Design Criteria Manual
Community Development Deparnnent SITE DEVELOPMENT
e. Residential lots must have a minimum of 120 feet of frontage in order to be
eligible for two driveways on the same lot and they shall have 50 feet of
separation between them.
£ Non-residential driveways shall be 25 feet to 35 feet wide. Non-residential
driveways shall be spaced with a minimum of 50-feet separation.
g. Non-residential driveways on major thoroughfares/boulevard streets shall be
placed no closer than 125 feet from the ultimate curb line of an intersecting
major thoroughfare or boulevard street. Non-residential driveways on
collector/ minor streets are to be placed no closer than 75 feet from the
ultimate curb line of an intersecting major thoroughfare/boulevard street. Non-
residential driveways on major thoroughfares/boulevard streets are to be
placed no closer than 75 feet from the ultimate curb line of an intersecting
collector commercial/minor street.
h. For purposes of determining the separation distance, the back of curb or edge
of street shall be used in conjunction with the edge of driveway which is
closest and parallel to the street.
i. Non-residential tracts with less than 150 feet of frontage on a public street shall
have no more than 1 driveway. Commercial tracts with between 150 and 320
feet of frontage on a public street shall have no more than 2 driveways.
Commercial tracts with between 321 feet and 600 feet of frontage on a public
street shall have no more than 3 driveways. Commercial tracts with over 600
feet of frontage on a public street shall have driveways specially designed and
specifically approved by the City.
j. Non-residential driveway connections to the public street shall be approved and
inspected by the City of Friendswood.
k. Driveway radii shall not extend beyond the projection of a property corner to
the back of the curb.
1. Driveways shall be installed according to the City of Friendswood
Construction Details.
m. Driveways shall be evaluated with respect to signage, landscaping and
structures for adequate sight distance.
n. A note stating, "Access to adjacent property and common driveways may be
required," shall be placed on the site plan.
o. Curb returns for driveways shall be, at a minimum:
i. For residential driveways:
a. 5 feet on local streets
b. 10 feet on collector streets, major thoroughfares and boulevards
ii. For non-residential driveways:
a. 25 feet on local streets
b. 35 feet on collector streets, majar thoroughfares,boulevards and
local streets less than 28 feet in width
8. Fire Lanes
a. Fire lane easements shall be required on all multi-family and non-residential
tracts if any part of a building is greater than 150 feet from either a fire lane or
a public street right-of-way.
b. Fire lanes sl�all be either 20 feet wide with a 25-foot radius or 25-feet wide
with 20 feet radius.
Revised 9/11/2006 Section VI Page 4 of 9
City of Friendswood Design Criteria Manual
Community Development Department SITE DEVELOPMENT
c. Fire lanes shall be constructed using the same pavement structural
requirements as a public pavement. Alternate materials may be used with
specific approval from the City.
d. Fire lanes shall be designed to drain in compliance with the Site Development
Requirement.
e. Fire lane markings shall be provided as specified in the Friendswood Code of
Ordinances.
9. Controlled Access Gate Requirements
a. Plans for access control systems shall be submitted to the Fire Marshal's
Office and approved prior to construction.
b. All access control gates shall have emergency means of operation in the
event of power loss.
c. Access control gates shall provide a clear, passable width of at least twenty
feet.
d. A Knox�key switch shall be provided for all controlled access gates. The key
switch shall operate all gates.
e. A Knox�pad lock shall be provided for all non-motorized gates.
£ The location of the key switch shall be approved by the Fire Marshal's Office.
g. The owner shall maintain all parts of the access system and keep them in
good working order.
h. The Fire Marshal's Office and Police Dispatch shall be notified
immediately of any damage to the access system that hinders access
including, but not limited to, damage to the key box, lock, or gates.
10. Pollution Prevention
A pollution prevention plan shall be provided for all site development projects.
a. Filter fabric fence shall be installed at the perimeter of the site before
construction is to begin.
b. Once construction is completed,either filter fabric fence, 5 feet of hydro mulch
or sod shall be installed at the back of all curbs, or other Best Management
Practices shall be implemented.
c. Refer to the storm water ordinance for additional requirements.
1 l. Parking Lot Guidelines
A parking lot layout is required to ensure that adequate off-street parking is provided
with the construction, alteration, remodeling or change of use of any building or
change in use of land.
a. Off-street parking spaces shall be located on the same lot, tract, parcel, or
premises as the use being served or on other property of the same or less
restrictive zoning classification that the owner of the premises being served has a
continuing right to use for parking. When the off-street parking spaces are not
located on the same lot,tract, parcel, ar premises being served, the distance from
the center of the parking lot to an entrance to the building or use shall not exceed
500 feet in distance, measured along the shortest available pedestrian route with
public access.
Revised 9/11/2006 Section VI Page 5 of 9
City of Friendswood Design Criteria Manual
Community Development Deparhnent SITE DEVELOPMENT
b. Any existing building or use that is enlarged, structurally altered,or remodeled to
the extent of increasing or changing the use by mare that 50 percent as it existed
shall be accompanied by off-street parking for the entire building or use. When
the enlargement, structural alteration, or remodeling is to the extent that the use is
not increased or changed by more than 50 percent, additional off-street parking
shall only be required for the increased or changed floor area or use.
c. Existing parking spaces may not be used to satisfy additional off-street parking
requirements unless the existing spaces exceed the number recommended for the
building or use for which the existing spaces are associated.
d. The number of off-street parking spaces recommended for each building or use
shall be determined by reference to the following table of parking groups. Where
several different properly uses will share a joint parking area, the parking should
be computed based upon the overall development. Shopping centers containing
not more than 200,000 square feet of gross leasable floor area should have a
minimum of six spaces per 1,000 square feet of gross leasable floor area.
Shopping centers containing more than 200,000 square feet of gross floor area
should have a minimum of 5.5 spaces per 1,000 square feet of gross leasable
floor area.
e. The Parking Group Table can be found in Appendix C.
£ The design and dimensions of off-street parking areas shall be in accordance with
the following table of minimum dimensions. Minimum stall width shall be nine
feet, except for residential and all-day office parking which may utilize stalls 8'/z
feet in width, provided that minimum aisle widths are increased by one foot. In
addition, the dimensions of up to 20 percent of the total number of off-street
parking spaces may be reduced to eight feet in width and 16 feet in depth to
accommodate compact automobiles. All dimensions below are in feet:
Angle
(degrees)
0° 35° 45° 60° 90°
Stall, parallel to aisle 23.0 18.0 12.7 10.4 9.0
Stall, perpendicular to aisle 9.0 16.5 19.0 20.0 18.0
Aisle width, one-way 12.0 12.0 12.0 16.0 24.0
Aisle width,two-way 22.0 22.0 22.0 24.0 24.0
Cross aisle, one-way 11.0 11.0 11.0 11.0 11.0
Cross aisle,two-way 22.0 22.0 22.0 22.0 22.0
Refer to Appendix B,Figure 8 for Off-street Parking Diagram
g. Off-street parking spaces shall be clearly marked. Parking spaces abutting an
adjoining property line or street right-of-way shall be provided with wheel guards
or bumper guards so located that no part of a normally parked vehicle will extend
beyond the property line. When wheel guards are used, they shall be centered
2.5 feet froin the property line for 90-degree parking, 2.3 feet for 60-degree
parking, and 2.0 feet for 45-degree and 30-degree parking
Revised 9/11/2006 Section VI Page 6 of 9
City of Friendswood Design Criteria Manual
Corrununity Development Department SITE DEVELOPMENT
h. Approval of the parking area layout and design of all off-street parking areas
shall be by the City Engineer. The City Engineer shall determine that spaces
provided are usable, and that the circulation pattern of the area is adequate.
i. Bonus for landscaping of off-street parking facilities. The minimum off-street
parking shall be reduced up to a maximum of 50 percent of the recommended
where an equal percent of the total parking area has been retained and developed
as landscaped open space area. The percent of the landscaped open space area
shall determine the maximum percent reduction, which will be permitted in the
total number of off-street parking spaces.
2.0 EXECUTION
2.01 RESEARCH REQUIREMENTS
A. Discuss project concepts outlining proposed features and usage with the City.
B. Research existing utility and right-of-way information.
C. Verify that no restrictions exist that will deny approval of the project concept.
2.02 DESIGN ANALYSIS—Reserved
2.03 DRAWINGS
A. Drawings shall include layout sheet(s) providing a photometric layout of the site complete
with location of proposed lights shown, information on light heights and type of light
standard proposed.
B. The plans shall include an overall drainage layout showing:
l. Total area(in acres)of site to be drained.
2. Area(in acres)drained to each inlet.
3. Contours or an adequate number of spot elevations to indicate area drained to each
inlet.
4. Top elevation and flowline elevation at each inlet.
5. Gradient and size on each private storm sewer.
6. Computations to support pipe sizes and grades shown (minimum private stonn size
shall be 10 inches.)
7. Design velocity for stonn sewers shall be 3 feet per second.
Revised 9/11/2006 Section VI Page 7 of 9
City of Friendswood Design Criteria Manual
Community Development Department SITE DEVELOPMENT
8. TX DOT permit shall be required for drainage affecting a state owned/maintained
facility. Submit permit with site plan.
9. The drawings shall be prepared and sealed by a Registered Professional Engineer.
10. The size and location of the detention facility shall be indicated on the plans, along
with the size and location of the outfall structure.
C. All site plans shall be approved by the appropriate drainage entity priar to City approval
being granted.
D. The site plan shall show all water and sewer service lines, sizes, grades and alignments with
appropriate ties into existing public trunk lines.
E. The site plan shall show all parking areas.
F. The site plan shall indicate the types and location of all existing and proposed landscaping.
Landscaping shall meet the minimum requirements of the Zoning Ordinance. A tree survey
is required for first 20 feet of depth adjacent to all proposed streets. If no trees exist, a note
to that affect shall be placed on the site plan. The qualified tree list can be found in
Appendix D.
G. The site plan shall show the location,height and area of all proposed buildings. All setback
lines shall also be shown with a dimension called out on the site plan between the building
and the site boundary.
H. The land use for all adjacent property shall be shown on the site plan.
I. All parking lot pavement for site plans shall be engineered to provide for regular use of
vehicles expected to utilize the parking area and based upon the soil conditions underlying
the parking area. A Registered Professional Engineer shall certify the design submitted for
approval.
J. Concrete sidewalks (a minimum of 4 feet wide and 4 inches thick with steel reinforcement)
shall be required along all street frontages. The design and installation of such sidewalks
shall comply with Texas Accessibility Standards Architectural Barriers requirements. The
location of all proposed and existing sidewalks shall be shown on the construction
drawings.
K. Show location of signs, screening walls or fences (indicate height, minimum 8 feet) and
dumpsters(with appropriate screening).
L. If the site is located within the Community Overlay
District, a plan note shall be made on the site plan indicating such; and that the site
development will conform the City Ordinance requirements.
Revised 9/11/2006 Section VI Page 8 of 9
City of Friendswood Design Criteria Manual
Community Development Department SITE DEVELOPMENT
M. No improvements to the right-of-way shall be made without prior City approval. This
includes planting trees in the right-of-way of residential and non-residential areas.
Revised 9/11/2006 Section VI Page 9 of 9
City of Friendswood Design Criteria Manual
Community Development and Public Works Deparhnent MODIFICATION PROCEDURES
SECTION VII
MODIFICATION PROCEDURES
The City of Friendswood Construction Board of Adjustment (hereinafter referred to as "The City") may
grant a modification to the Design Criteria Manual, if the developer/owner can prove that the listed
circumstances apply. A written application by the developer/owner must be filed with the City along with
sealed engineering reports, drawings, etc. The following is a list of circumstances to apply for a
modification.
1. There is no available alternative or option that would allow compliance with the
Design Criteria Manual in lieu of a modification; and
2. There are no special circumstances or conditions affecting the applicant's land
involved such that the strict application of the provisions of this chapter would deprive the
applicant of all reasonable use of his land; and
3. The granting of the modification will not be detrimental to the public health, safety, or
welfare;or injurious to other property in the area; and
4. The granting of the modification will not increase the 100-year flood plain base flood
elevation on the upstream or downstream side of the applicant's property; and
5. The granting of the modification will not have the affect of preventing the orderly
development of other land in the area in accordance with the provisions of the Design Criteria
Manual.
The City may grant a modification to the Design Criteria Manual if it determines, based upon the
evidence presented, that an undue hardship may result from strict compliance with the Design Criteria
Manual. Pecuniary hardship to the developer, standing alone, shall not be deemed to constitute undue
hardship.
A modification may be granted so that substantial justice is done and the public interest secured,provided
that such modification shall not have the effect of nullifying the intent and purpose of the Design Criteria
Manual.
A Design Criteria Modification Form is included as Attachment 3.
Revised 9/11/2006 Section VII Page 1 of 1
CITY OF FRIENDSWOOD
COMMUNITY DEVELOPMENT DEPARTMENT
Design Criteria Manual
September 11, 2006
Appendix A
Attachments
ATTACHMENTS
1. Lift Station Start-up Log
2. ANSI/NSF Standard 60 and 61 Certification
3. Design Criteria Modification Form
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Attachment 2
TEXAS NATURAL RESOURCE CONSERVATION COMMISSION
PDW PROGRAM STAFF GUIDANCE
GuidanceTitle: ANSI/NSF STANDARD 60 AND 61 CERTIFICATION
Rules Affected: 30,TAC, §290.42(I), §290.43(c)(8), §290.44(a)(1) and §290.44(I)(2)(B)
PAGE 1/1
Sections§290.42(I),§290.43(c)(8), §290.44(a)(1)and§290.44(I)(2)(B)in our current Rules and Regulations for
Public Water Systems concern ANSI/NSF product certification for ail direct and indirect additives used in the
production,treatment,storage and distribution of public drinking water. All such products must conform to
ANSI/NSF Standard 60 for direct additives and ANSI/NSF Standard 61 for indirect additives as of January 1,
1993. Since these requirements went into effect wee have been contacted by a number of water system officials
and consulting engineers concerning the limited availability of materials which meet these standards. In addition,
manufacturers and distributors have informed us of lengthy delays in the certification process. We feel that these
concerns are valid and that an interim guidance is necessary until more materials have made their way through
the certification process.
• The following guidance has been established:
All materials which come in direct or indirect contact with public drinking water in any stage
of treatment must conform to ANSI/NSF Standard 60 for direct additives and ANSI/NSF
Standard 61 for indirect additives. Should no certified material for the intended purpose exist
or if there are no such certified materials currently marketed in the State of Texas, a material
may be conditionally accepted for use if:
1. The material was previously approved by a nationally recognized authority such as EPA,
NSF, USDA or USFDA for direct, indirect or incidental contact with water and/or food,
and
2. Proof of submission of the material to an organization accredited by ANSI for
certification under ANSI/NSF Standards 60 and 61 is provided. Such proof shall consist
of either a dated receipt from NSF, UL or other ANSI accredited organization or a letter
from the accredited organization acknowledging that the material has been submitted
for evaluation and certification.
The conditional acceptance of any single product shall expire when the conditionally accepted product or an
alternate competing product receives certification and is marketed within the State of Texas, or the conditionally
accepted product is denied certification by an ANSI accredited organization.
END
January 1, 1996 N/A ���� �: �a/��
Effective Date Expiration Date Steven E.Walden, R.S., Manager
Public Drinking Water Section
Water Utilities Division
Attachment 3
CITY OF FRIENDSWOOD
DESIGN CRITERIA MODIFICATION FORM
se�t�on vII.
Variations to technical standards identified in the Design Criteria Manual may be permitted by the City of
Friendswood City Engineer . The modification proposal must be submitted by a registered professional engineer
following generally accepted engineering standards for traffic, sidewalk and other infrastructure as applicable, and
such proposal contains the following information and substantiates the findings in paragraph four (4) below. If an
appeal to the City of Friendswood City Engineer decision is requested, The Construction Board of Adjusnnent
(hereinafter referred to as"the City")will review that appeal.
PROJECT NAME:
This entire form must be completed in its entirety. If form is submitted
incomplete,it will be administratively rejected.
PROJECT ENGINEER:
SUBMITTAL DATE:
SUBDIVISION NAME:
MODIFICATION
LOCATION:
1. Set forth the proposed deviation to the technical standard.
SPECIFIC PROPOSED DEVIATION FROM TECI3NICAL STANDARD:
2. Set forth the impact such deviation has on speed differential and street capacity, the likelihood of accidents, the
long term maintenance and operation effect, the degree of functionality and efficiency, the technological
advancements involved,and other relevant matters.
IMPACT OF DEVIATION:
3. Show a comparison of the technical standard to the proposed deviation with respect to overall safety and quality,
speed differential, street capacity, existing and projected accidents, long-term maintenance and operation, degree
of functionality,degree of efficiency,technological advancements,and other relevant matters.
COMPARISON OF TECH1vICAL STANDARD TO PROPOSED DEVIATION:
4. Describe all mitigating improvements that reduce the negative impact of the proposed deviation on overall safety
and quality, speed differential, street capacity, accident occurrences, long-tenn maintenance and operation,
degree of functionality, degree of efficiency and demonstrating the degree to which the proposed deviation
detrimentally affects the foregoing. Other relevant factors, including technological advances, should be
explained by describing how they will affect the proposed development. Mitigating improvements can include
but are not limited to, traffic control devices, pavement improvements, added acceleration or deceleration lanes
or reservoirs,and other on-site improvements.
MITIGATING IMPROVEMENTS THAT REDUCE NEGATIVE IMPACT:
SUMMARY&CONCLUSION/RECOMMENDATION FOR MODIFICATION:
List of Supporting Documentation Attached? Yes No
Seal of Professional Engineer:
Community Development Use ONLY
Reviewed By:
Date
Modification Request Approved / Denied By:
Copies of Backup Information/Notes Attached
Director Date
Cotmnunity Development
CITY OF FRIENDSWOOD
COMMUNITY DEVELOPMENT DEPARTMENT
Design Criteria Manual
September 11, 2006
Appendix B
Figures
Figure
1. Geometric Street Design Standards
2. Divided Roadway Cross Sections— Urban
3. Roadway Tapers For Subdivision Streets
4. Undivided Roadway Cross Sections — Urban
5. Typical Length of Median and Median Opening
6. Median Nose and Left Turn Bay Design
7. Offstreet Parking
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NOTE: 18'
Minimum stall widths shall be nine ♦ � g �
feet, except for vesidential and � MIN.
oll—day office parking which may � � � � � �
utilize stalls SS�2 feet in width, pravided
thOt the minirnurn aisle widths are
increosed by one foot. In oddition, ( �.► 11' � "♦
the dimensions of up to 2a percent
of the totai number of offset porking � �
spaces rnay be reduced to eight feet � � � � � �
in widths ond 16 feet in depth to I
occomrnodate compact autornobiles.
Parking spaces abutting an odjoininq ( �� �G�
property line or streei right of way
sholl be provided with wheel guords I
or bumper guords so located that no
part of a norrnaliy parked vehicle w�ll �6� 24�
extend beyond property line. � � � � � �
Wheel � � �
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� " QFFSTREET PARKING
STALL PERPENQICULAR TO AISLE
COMNiUNITY DEVELOPMEf�T DRAWN: 05/04 N.T.S.
DETAIL: offstreetparking
CITY OF FRIENDSWOOD
COMMUNITY DEVELOPMENT DEPARTMENT
Design Criteria Manual
September 11, 2006
Appendix C
Parking Group Table
Parking Use Category Recommended Parking Spaces
Accommodation 1 '/2 spaces for each room/dwelling unit
Accommodation&Food Services 1 space for every 4 seats or 1 space for every 50 sq. ft. of
customer service area,whichever is greater
Adult establishment 1 space for every 4 seats or 1 space for every 50 sq. ft. of
customer service area,whichever is greater
Agricultural,Forestry,Fishing And 2 per site+ 1 per 1,000 sq. ft. enclosed floor area
Hunting Uses
Arts,Entertainment&Recreations 1 space for each 250 sq. ft. gross floor area
Broadcast&Telecommunications; 1 space for each 300 sq. ft. of gross floor area
Telecommunication Resellers:
Information&Data Processing
Services
Car wash 2 per wash bay, 3 stacking spaces per bay
Civic, Social and Fraternal 1 space for each 300 sq. ft. of gross floor area
Associations
Educational Services TBD
Finance&Insurance 1 space for each 300 sq. ft. of gross floor area
Gas Station 1 space for each bay, plus 1 space for each pump island,
ininimum 6 spaces
Health Care& Social Assistance 1 space for each 250 sq. ft. gross floar area
Hospitals,Nursing&Residential Care 1 space for each 1 '/2 beds
facilities
Information Services 3 spaces for each 5 employees on largest shift, or 1 space per
600 sq. ft. of gross floor area
Mining,Utilities, Construction, 3 spaces for each 5 employees on largest shift, or 1 space per
Manufacturing, Transportation& 600 sq. ft. of gross floor area
Warehousing
Mobile home 2 '/2 spaces per trailer unit
Non-store retailers TBD
Other Amusement and Recreation TBD
Industries
Other Services 1 space for each 250 sq. ft. gross floor area
Professional, Scientific &Technical 1 space for each 300 sq. ft. of gross floor area
Services: Management of Companies
&Enterprises;Administration/Support
Services
Public Administration TBD
Real Estate, Rental &Leasing TBD
Religious Organizations 1 space for each 4 seats in the largest auditorium, or 1 space
for each 800 square feet of gross floor area, which ever is
larger
Residential Uses 2 spaces per household
Retail Trade 4 spaces for each 1,000 sq. ft. gross floor area
Transit& Ground Passenger TBD
Transportation; Scenic & Sightseeing
Transportation
Truck Transportation; Warehousing& 1 space for each 1,000 sq. ft. non-office floor area plus 1
Storage space for each 300 sq. ft. office area
Vehicle Dealers 1 space for each 5,000 sq. ft. of lot area
Whole Sale Trade TBD
CITY OF FRIENDSWOOD
COMMUNITY DEVELOPMENT DEPARTMENT
Design Criteria Manual
September 11, 2006
Appendix D
Qualified Tree List
Qualified Tree list by class of tree
Common name Botanical name Class N/I Site Light Size E/D
Bald Cypress Taxodium distichum 1 N 2,3 2 1 D
Bur Oak Quercus macrocarpa 1 N 2 1 1 D
Cedar Elm Ulmus crassifolia 1 N 2 1 2 D
Acer rubrum var.
Drummond Red Maple drulnlllondii 1 N 2 1 2 D
Eastern Redbud Cercis canadensis 1 N 2 2 2 D
Live Oak Quercus virginiana 1 N 2 1 1 SE
Overcup Oak Quercus lyrata 1 N 2,3 1 1 D
Pecan Carya illinoensis 1 N 2 1 1 D
Possumhaw Holly Ilex decidua 1 N 2 1,2 3 D
Shumard Red Oak Quercus shumardii 1 N 2 1 1 D
Southern Magnolia Magnolia grandiflara 1 N 2 1 1 E
Swamp Chestnut Oak Quercus michhauxii 1 N 2,3 1 1 D
Sweet-Bay Magnolia Magnolia virginiana 1 N 2 2 2 E
Wax Myrtle Myrica cerifera 1 N 2/3 1 3 E
American Elm Ulmus americana 2 N 2 1 1 D
American Sycamore Platanus occidentalis 2 N 2 1 1 D
AnacualSandpaper Tree Ehretia anacua 2 N 2 1 2 E
Arrow-wood Viburnum Viburnum dentatum 2 N 2 2 3 D
Black Hickory Carya texana 2 N 2 1,2 2 D
Black Walnut 7uglans nigra 2 N 2 1,2 1 D
Blcakgum Nyssa sylvatica 2 N 2,3 1,2 3 D
Callery Pear/Braford Pyrus calleryana 2 I 2 1 3 D
Carolina buckthorn Rhamnus caroliniana 2 N 2 1,2 3 D
Chalk Maple Acer leucoderme 2 N 2 2 2 D
Cherry Laurel Prunus caroliniana 2 N 2 2 2 E
Chinese Elm Ulmus parvifolia 2 I 2 1 2 D
Chinquapin Oak Quercus muhlenbergii 2 N 2 1 1 D
Common Crapemyrtle Lagerstroemia indica 2 I 2 1 3 D
Common Fig Ficus carica 2 I 2 1 3 D
Common Persimmon Diospyros virginiana 2 N 2 1 2 D
Eastern Red Cedar Juniperus virginiana 2 N 2 1,2 2 E
Eve's Necklace Sophora afFinnis 2 N 1 1 3 D
Green Ash Fraxinus pennsylvanica 2 N 2,3 1,2 1 D
Huisache Acacia farnesiana 2 N 1 1 3 D
Loblolly Pine Pinus taeda 2 N 2 1 1 E
Mexican Plum Prunus mexicana 2 N 1 1 3 D
Nuttail Oak Quercus nuttallii 2 N 2/3 1 1 D
Ornamental Holly Ilex spp. 2 I 2 1,2 3 E
Paloverde Parkinsonnia aculeata 2 N 1 1 2 D
Parsley Hawthorn Crataegus marshallii 2 N 2 2 3 D
Post Oak Quercus stellata 2 N 2 2 1 D
Red Bay Persea borbonia 2 N 2 2 2 E
River Birch Betula nigra 2 N 2,3 2 2 D
Rough-leaf Dogwood Cornus drummondii 2 N 1,2 3 3 D
Rusty Blackhaw Viburnum Viburnum rufidulum 2 N 2 2 3 D
Sassafras Sassafras albidum 2 N 2 2 2 D
Scarlet(Red)Buckeye Aesculus pavia 2 N 2 2 3 D
Shagbark Hickory Carya ovata 2 N 2 1 1 D
Slash Pine Pinus elloittii 2 I 2 1 1 E
Snowbell Styrax americana 2 N 2 1,2 3 D
Southern Red Oak Qurcus falcata var.pagoda 2 N 2 1 1 D
Sweetgum Liquidambar styraciflua 2 N 2 1 1 D
Texas Mountain-Laurel Sophora secundiflora 2 N 1 1 3 E
Texas Persimmon Diospyros virginiana(male) 2 N 1 1 3 D
Texas Pistache Pistacia texana 2 N 1 1 3 D
Texas Redbud Cercis canadensis texensis 2 N 1,2 2 3 D
Water Hickory Carya aquatica 2 N 2,3 1 2 D
Water Oak Quercus nigra 2 N 2/3 1 1 D
Western Soapberry Sapindus drummondii 2 N 2 1 2 D
White Ash Fraxinus americana 2 N 2 1 1 D
White Oak Quercus alba 2 N 2 1 1 D
Willow Oak Quercus phellos 2 N 2/3 1 1 D
Winged Elm Ulmus alata 2 N 2 1 2 D
Woollybucket Bumelia Bumelia lanuginosa 2 N 2 2 2 D
Wright Acacia Acacua wrightii 2 N 1 1 3 D
Yaupon Holly Ilex vomitoria 2 N 2 1/2 3 E
American Elderberry Sambucus canadensis 3 N 2 2 3 D
American Holly Ilex opaca 3 N 2 2 2 E
American Hornbean Carpinus caroliniana 3 N 2 2 2 D
Black Locust Robinia pseudoacacia 3 N 2,3 1 2 D
Black Willow Salix nigra 3 N 3 1 2 D
Box-Elder Maple Acer negundo 3 N 2 2 2 D
Camphor-Tree Cinnamomum camphora 3 I 2 1 2 E
Catalpa Catalpa bignonioides 3 N 2 1 2 D
Common Pear Pyrus communis 3 N 2 1 2 D
Eastern Cottonwood Populus deltoides(male) 3 N 2 1 1 D
Flowering Crabapple Malus spp. 3 I 2 1 3 D
Hercules-Club Prickly-Ash Zanthoxylum clava-herculis 3 N 1 1 3 D
Honey-Locust Gleditsia triacanthos 3 N 2,3 1 2 D
Japanese Yew Podocarpus macrophyllus 3 I 2 1 2 E
Japanese Maple Acer palmatum 3 I 2 2 3 D
Loquat Eriobotrya japonica 3 I 2 2 3 E
Mesquite Prosopis glandulosa 3 N 1 1 2 D
Mexican Buckeye Ungnadia speciosa 3 N 1 1 3 D
Red Mulberry Morus rubra 3 N 2 1 2 D
Sugar Hackberry Celtis laevigata 3 N 2 1,2 2 D
Vitex Vitex agnus-castus 3 I 1 1 3 D
Water Tupelo Nyssa aquatica 3 N 3 2 1 D
Weeping Willow Salix babylonica 3 I 3 1 2 D
Arborvitae Thuja spp. 4 I
Arizona Ash Fraxinus velutina 4 I
Berlandier Ash Fraxinus berlandieriana 4 I
Chinaberry Melia azedarach 4 I
Chinese Pistache Pistacia chinensis 4 I 2 1 2 D
Chinese Tallow Sapium sebiferum 4 I
Eucalyptus Eucalyptus spp. 4 1 1,2 1 3 E
Golden-Raintree Koelreuteria paniculata 4 I 2 1 2 D
Japanese Black Pine Pinus thunbergi 4 I 2 1 2 E
Mimosa(Silktree) Albizia julibrissin 4 I
Mulberry Morus alba 4 I 2 1 2 D
Siberian Elm Ulmus pumila 4 I
Silver Maple Acer saccharinum 4 I
Tulip-Tree Liriodendron tulipifera 4 I 2 1 1 D
Trees are divided into four classes. Class one and two trees are considered the most valuable in enhancing the environment
and are the most likely to prosper in the Friendswood area. Therefore, only class one and two trees shall be approved as
new plantings for streets,public right-of-ways, city parks and property, and parking lots unless otherwise approved by the
city zoning officer on the advice of an Urban Forester. Species that are classified as shade trees will reach a height and size
that will conflict with overhead powerlines,permanent structures, or the canopy will exceed the limits of a confined space.
Species that are classified as small trees will not provide the protection or aesthetic impact of a large shade tree,yet they
are suitable for planting beneath powerlines and are good alternatives for areas of limited space.
Class 1: for the most part this classification is for trees that are native,will do relatively well in the Friendswood area, have
few diseases or pest problems, are easy to find in local nurseries and with few exceptions(redbud, possomhaw and
waxmyrtle) are larger in size.
Class 2:this classification is for trees that are mostly native, will still do well in the Friendswood area, have little disease
or pest problems, sometimes not quite as easy to find in nurseries, are more varied in size and in many cases are more
suitable for wildlife. These trees tend to have either larger and messier fruit and/or are thornier than trees in class one.
Some of these trees are also more prone to some decay at maturity and might not do as well in urbanized areas.
Class 3: this classification starts to pick up more introduced species,the trees might or might not do as well in the
Friendswood area,require a little more maintenance and care,the natives might be harder to find in a nursery while the
introduced species may be mare readily available and in some cases these trees are more prone to decay, disease and pest
problems.
Class 4: this classification is exclusively introduced species. They may or may not do well in Friendswood, if they do
grow well they have the potential to become invasive species and cause problems for local ecosystems and are more prone
to decay, disease and pest problems.NOT RECONIlVIENDED FOR PLANTINGS.
Classifications
N--Native
I—Introduced
Site
1--Xerophytic(requires little water)
2--Mesic(requires moderate water with good drainage)
3--Aquatic(tolerates poar drainage once established 3 years)
Once Established
Size
1--60 feet and greater ultimate height(large shade tree)
2--30 to 60 feet in ultimate height(medium tree)
3--30 feet and less in ultimate height(small tree)
Foliage.
D--Deciduous(sheds leaves annually)If placed on the south and west walls will reduce indoor temperatures in summer
by shading the roof and walls. In winter,these trees allow sunlight through to help heat the house.
E--Evergreen(having green leaves/needles through out the year)Can create a wind break if placed on the Northwest
side of a building.
SE--Semi evergreen
Far example,the code for Live Oak is 1/N/2/1/1,which indicates that the Live Oak is a class one species that is native to
Texas, requires moderate water with good drainage, demands or tolerates full sun, and will exceed 60 feet in ultimate
height. As a shade tree,the Live Oak will provide protection and has aesthetic impact but the tree is not suitable for
planting beneath powerlines or within confined spaces.