The intention of these standards is to define minimum requirements
for street, utility, and drainage construction in new subdivisions
within the jurisdiction of the city. These standards are supplementary
to the city's subdivision development ordinance, including subsequent
amendments.
(Ordinance 2874, ex. A, adopted 10/22/18)
The following minimum standards apply to subdivision street
paving:
(1) Type.
Reinforced concrete surface with concrete curb
and gutter.
(2) Pavement width.
(A) Major streets:
Forty-four feet (44’) to sixty-four
feet (64’) between back of curbs.
(B) Secondary streets:
Thirty-eight feet (38’) to
forty-four feet (44’) between back of curbs.
(C) Residential streets:
Twenty-eight feet (28’) to
thirty-two feet (32’) between back of curbs.
(3) Cross-section.
A standard cross-section for a residential
street is shown in figure I. Cross-sections for secondary and major
streets shall be proportioned similarly. At intersections, curb return
radius shall be twenty-five feet (25’); at cul-de-sacs, forty-five
feet (45’).
(4) Concrete.
(A) Reinforcing steel.
(i) Material: Open hearth new billet steel.
(ii)
Yield strength: 60,000 psi, minimum.
(iii)
Splices: Twenty-four (24) bar diameters.
(iv)
Bar size and spacing: No. 3 bars at eighteen inch (18”)
centers, each way, minimum. Street should be designed based upon the
subgrade and load use of street.
(v) Bar support: Metal or plastic “chairs” shall be used
to hold bars in position during placement of concrete.
(B) Concrete mixture.
(i) Compressive strength: 3,000 psi, minimum at twenty-eight (28) days.
(ii)
Slump: Four and one-half inches (4-1/2”) maximum.
(iii)
Cement factor: 5.0 bags per cubic yard, minimum.
(C) Cement.
Type I (normal) Portland cement, or with city
engineer's approval, type III (high early strength).
(D) Aggregate.
Coarse and fine aggregate shall meet the
requirements of Texas Department of Transportation Standard Specification
“Item 360” for concrete pavement.
(E) Jointing.
(i) Expansion joints with sleeved load transmission dowels: At intersections.
Also every eighty (80) linear feet, minimum.
(ii)
Wood joints: Sound heart redwood.
(iii)
Joint seal: QA 90 asphalt or other types with approval.
(F) Curing.
Curing method shall retain at least ninety-seven
percent (97%) of moisture at twenty-four (24) hours, at least ninety-five
percent (95%) at three (3) days, and at least ninety-one percent (91%)
at seven (7) days. (ASTM procedure C-5)
(G) Tests.
Compressive strength: Three (3) cylinders per
two hundred (200) linear feet.
(H) Placement.
Concrete shall not be placed on frozen subgrade;
when air temperature is thirty-eight (38) degrees F or below; when
air temperature is below forty-two (42) degrees F and declining; when
finishing cannot be completed during natural daylight.
(5) Subgrade.
(A) Rolling machinery: All subgrade shall be rolled.
(B) Density required: At least ninety-five percent (95%) of maximum density
(Standard Proctor density test).
(C) Lime stabilization: Required when plasticity index (P.I.) of subgrade
soil exceeds 18.
(D) Cement stabilization: Required when low P.I. “spongy”
or wet soils are encountered.
(E) Subgrade shall not be allowed to dry before concrete or base is placed,
nor shall concrete or base be placed on frozen subgrade.
(F) Density tests: At two hundred (200) linear feet intervals, or closer
when requested by city engineer. Density tests shall be “staggered”
across the width of the pavement. At no point should density texts
be taken in a straight line. At least one density test must be taken
on the outside edge of the pavement in culde-sacs.
(Ordinance 2874, ex. A, adopted 10/22/18)
Sidewalks shall meet the following minimum standards.
(1) Dimensions.
(A) Width: Four feet (4’), zero inches (0”), minimum.
(B) Thickness: Zero feet (0’), four inches (4”), minimum.
(2) Subgrade.
Two inches (2”) of compacted sand.
(3) Cross slope.
One-fourth inch (1/4”) per foot,
toward curb. Slopes on sidewalks must be ADA compliant.
(4) Reinforcing shall be #3 rebar at no greater than 18” C-C or
#6 6 × 6 welded wire mesh supported by either chairs or c.m.u.
bricks.
(5) Load transmission devices (dowels) shall be #4 rebar, 12” long,
embedded 6” either side of expansion joint, one end shall be
sleeved. Set load transmission devices 12” C-C, maximum.
(6) Expansion joints are to be spaced 10’ C-C and are to be sound
heart redwood, 3/4” thick with QA 90 asphalt or approved seal.
(7) Control joints are to be cut (1/4” x 1/2”) at no greater
than 5’ C-C spacing.
(Ordinance 2874, ex. A, adopted 10/22/18)
The following minimum standards apply to water system design
and installations within the city:
(1)
Main lines.
(A)
Minimum diameter.
Six inches (6").
(B)
Depth.
Three feet six inches (3'-6") of cover
below final grade.
(C)
Material.
C-900 PVC DR 18.
(D)
Location.
In permanent dead end situations the
water line shall be 6-inch (6") diameter or larger, shall not exceed
more than 500 feet in length from the closest interconnection water
line and shall terminate with a fire hydrant.
(E)
Tracer wire shall be laid (continuous) on top of pipe and up
through every valve box.
(2)
Valves.
(A)
Locations.
At tees - two (2) valves. At crosses
- three (3) valves. At each connection to existing water system -
one (1) valve.
(B)
Type.
Non-rising stem, O-ring seals, Mueller,
or equal product approved by the city engineer resilient wedge valve.
Counterclockwise opening, mechanical joint.
(3)
Fire hydrants.
(A)
Locations.
At each street intersection and cul-de-sac
end. Single-family residential areas: five-hundred-foot (500')
intervals, maximum. Commercial, including reserves: three hundred
and fifty-foot (350') intervals, minimum.
(B)
Type.
Mueller or equal product approved by the
city engineer 3-way 5-1/4" barrel with 4-1/2" steamer (pumper) nozzle
and two (2) 2-1/2 inch hose nozzles. Counterclockwise opening, mechanical
joint. Each fire hydrant is to have an individual gate valve (with
adjustable riser box) located within 4 feet of the fire hydrant.
(4)
Fittings.
(A)
Material.
ANSI A21.10 (AWWA C110) cast iron, mechanical
joint, ANSI A21.4, cement lined with seal coat; ANSI A21.16 fusion
bonded epoxy coating for interior; comply with NSF 61-G. All fittings
are to be thrust blocked with concrete and restrained. All fittings
are to be wrapped with plastic or similar materials to prevent concrete
from adhering to the mechanical joint connection components.
(5)
Services.
(A)
Corporation stop.
Mueller H-15000 (flare) or H-15008
(compression) or equal product or approved by the city engineer.
(B)
Curb stop.
Mueller B25168 (flare) or B25170 (compression)
or equal product and approved by the city engineer, ending in an approved
concrete or plastic meter box. (All boxes in new development are to
be of the same material.)
(C)
Meter coupling required.
Mueller H-10896 or equal
product and approved by the city engineer.
(D)
Pipe material.
Soft copper.
(E)
Size.
1", one per each residential lot.
(F)
Concrete or plastic meter box of appropriate size is required.
(G)
All curbs are to be marked to indicate the location of the water
services for each individual lot.
(H)
Tap and sleeve, Muller or Smith & Blair or equal product
and approved by the city engineer (stainless steel band and bolts,
epoxy coated saddle).
(I)
Sensus radio read meters with MXU assembly.
(6)
Backfill.
(A)
Under future streets.
Wrap water line with 6"
layer of bank sand, remainder of trench to be filled with 1.0 sack
(100 psi) per cubic yard cement stabilized sand, compacted to 95%
Proctor.
(B)
Under existing streets.
Water lines are to be
installed by trenchless methods.
(C)
Other locations.
Wrap water line with a 6" layer
of bank sand, remainder of trench to be filled using compacted native
soil. Sandy soil must be water jetted; other soils may be compacted
by rolling with a "caterpillar" tractor or similar method.
(D)
All trenches are to be compacted to 95% Standard Proctor.
(1999 Code, sec. 9.504; Ordinance 3039 adopted 5/23/2022)
All homes must be connected to the city's central sanitary sewer
system. The following minimum standards apply to sanitary sewer extensions
within the city:
(1) Main lines.
(A) Minimum diameter:
Six inches (6”).
(B) Minimum depth:
Four feet (4’), zero inches (0”).
Exceptions may be made on depth with city public works director approval.
(C) Material:
(ii)
Fittings: Same class as pipe, with rubber gaskets.
All sanitary sewer lines must be air tested and pass deflection
testing 30 days (or longer) after installation. The city reserves
the right to require filming of any sewer installation, at the developer's
expense.
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(2) Manholes.
(A) Size:
(i) Four feet (4’), zero inches (0”) inside diameter.
(ii)
Thirty-two inch (32”) diameter opening in cone section
for access to the sanitary sewer for cleaning and maintenance.
(B) Spacing:
Three hundred feet (300’) maximum and
at changes in direction or size of main line.
(C) Material:
(i) Pre-cast concrete manhole meeting ASTM C478 (latest revision).
(ii)
Cast-in-place manholes shall be 4000 psi concrete with wall
thickness of no less than five inches (5”). The base shall be
no less than twelve inches (12”) thick.
(D) Pipe connection:
Each pipe connection to sanitary sewer
manholes shall be made watertight by either:
(i) Approved flexible connectors; or
(E) Foundations:
Place manhole base on twelve inches (12”)
minimum of compacted cement stabilized sand.
(F) Manhole ring and lid:
(i) Install thirty-two inch (32”) diameter cast iron ring using
approved sealant.
(ii)
In pavement: Adjust ring and cover to grade. (The city may require
infiltration prevention measures, to be decided on a case-by-case
basis. If they are required the developer must pay for them.)
(iii)
In unpaved areas: Adjust ring and cover to at least six inches
(6”) above surrounding grade, sloping grade away from the manhole.
(iv)
Manhole lid is to have “sanitary sewer” cast into
it. No other reference is to be cast into the lid.
(3) Services.
(A) Minimum sizes:
(i) Residential: Single service - four inches (4”); double service
- six inches (6”).
(ii)
Commercial: Six inch (6”) minimum.
(B) Material:
Sch. 40 or SDR 26 PVC.
(C) Fittings required:
Wye, bend, and plug.
(D) Stack required:
Where sewer depth exceeds six feet (6’),
zero inches (0”).
(E) Marking:
“As built” plans required showing
locations, with 4” x 4” oak timber marking each service
and extending two feet (2’) above ground. Painted with a bright
color paint. (Capped four inch (4”) diameter PVC pipe may be
used in lieu of the oak timber.) Curb is to be marked to indicate
the location of the sanitary sewer service.
(F) Bedding:
Cement-stabilized sand (one sack per cubic
yard). Thickness to be one-half (1/2) of the pipe diameter beneath
the pipe (in no case less than 6” thickness) and to the centerline
of the pipe.
(4) Backfill.
Same as for water systems.
(5) Location.
Except in unusual circumstances and after
recommendation by the city engineer and approval of CPZ, sanitary
sewer mains shall be located in front of lots. They shall be placed
within street rights-of-way opposite water mains. If authorized to
be placed at rear of lot, mains shall be no closer than five feet
(5’) to the easement boundary.
(1999 Code, sec. 9.505)
(a)
The following minimum standards apply to drainage construction
within new subdivisions.
(1)
Storm sewers and culverts.
(A) Minimum diameter.
Twenty-four inches
(24"); eighteen inches (18") for pipe serving one (1) inlet.
(B) Minimum slope:
Storm sewers - 0.1%
or as approved by city engineer. Culverts shorter than one hundred
feet (100') - 0.1% or as approved by the city engineer.
(C) Material:
(i) Class III reinforced concrete pipe.
(ii) High density polyethylene (HDPE) corrugated smooth
lined thermoplastic pipe may be used in non-roadway areas when approved
by the city engineer.
(iii) Texas Department of Transportation and Harris
County Flood Control District standard specification box culverts
and headwalls.
(D) Joints:
(i) Class III reinforced concrete pipe: Bell and spigot
joints with "O" ring type gaskets.
(ii) High density polyethylene pipe: Bell and spigot
joints with "O" ring type gaskets.
(iii) Box culverts: "Ram-Nek" type asphaltic sealer
or approved equal with joints to meet Texas Department of Transportation
or Harris County Flood Control District specifications.
(E) Bedding:
All storm sewer is to be
bedded with one and one-half (1-1/2) sack per cubic yard of cement-stabilized
sand, compacted to twelve inches (12") thickness, minimum.
(F) Backfill:
All storm sewer piping
shall be backfilled to a minimum of twelve inches (12") over the top
of the pipe with one and one-half (1-1/2) sack per cubic yard cement-stabilized
sand, compacted by mechanical means. When using HDPE pipe, caution
shall be taken to ensure proper bedding and backfill to meet the manufacturer's
recommendations to provide the structural support necessary.
(G) Junction boxes and manholes:
(i) Size: Nominal pipe size plus twelve inches (12").
(ii) Material: Reinforced concrete, designed for traffic
loading. Minimum wall thickness - 5".
(iii) Location:
a. At changes in pipe size or direction.
b. At distances not to exceed four hundred feet (400')
or as approved by the city engineer.
(iv) Access covers: Twenty-four inch (24") or thirty-two
inch (32") diameter cast iron ring and cover with the word "storm"
cast into the cover.
(H) Inlets:
(i) Minimum throat size: Six inches (6") high by five
feet (5') long.
(ii) Material: Reinforced concrete, designed for traffic
loading.
(iii) Minimum wall thickness: Five inches (5").
(iv) Access: Twenty-four inch (24") or thirty-two inch (32") diameter cast iron ring and cover (see subsection
(G)(iv) above).
(I) Trench drainage:
"Trench drains"
are allowed only in the Old Katy District (OKD) zoning district.
(2)
Open channels.
(A) Unlined ditches:
Side slopes - Three
(3) horizontal, one (1) vertical steepest allowable side slope. Bottom
slope - 0.05% minimum. Easement width - Top width plus sixteen feet
(16') on one (1) side of the channel and six feet (6') wide
on other side of the channel.
(B) Lined channels:
Bottom slope - 0.05%
minimum. Lining material - Minimum five inch (5") thick concrete with
minimum #3 bars at eighteen inches (18") center to center. With approval
of the city engineer, pre-cast concrete interlocking pavers may be
used in lieu of concrete. Concrete characteristics - Same as for street
paving. Easement width - Top width plus twelve feet (12') on
one (1) side of the channel and four feet (4') on the other side
of the channel.
(3)
Design criteria.
(A) Storm period:
(i) Open Channels:
Twenty-five (25) year
storm capacity contained within the top bank with 1' vertical
freeboard based on normal depth starting hydraulic grade line; and
for new development as required to prevent structural flooding during
the 100-year storm. Storm sewers - Two-year storm contained within
the pipe without surcharging; and with the calculated hydraulic grade
line for the 100-year storm to be no higher than 12-inches above the
top of curb or center of roadway with all means of conveyance considered.
(ii) Hydrology and methodology for the design of open
channels and detention ponds - As per Harris County Flood Control
District PCPM dated July 2019.
(iii) Hydrology and methodology for the design of storm
sewers and box culverts - As per current City of Houston Infrastructure
Design Manual - current version in effect at the time of initial plan
submittal.
(B) Runoff coefficient:
As per current
City of Houston Infrastructure Design Manual - current version in
effect at the time of the initial plan submittal.
(b)
The following minimum standards apply to all drainage construction
within the Addicks Reservoir Watershed, Barker Reservoir and Cypress
Creek Watershed Upstream of US 290.
(1)
Harris County Flood Control District's "Supplemental Guidelines
and Criteria for Developing in the Addicks Reservoir Watershed, Barker
Reservoir Watershed, and Cypress Creek Watershed Upstream of US 290,"
dated March 2016.
(2)
Harris County Flood Control District's Policy and Procedures
Manual.
(3)
Where there is a conflict with the Harris County Flood Control
District's Policy and Procedures Manual and or the Harris County
Flood Control District's "Supplemental Guidelines and Criteria
for Developing in the Addicks Reservoir Watershed, Barker Reservoir
Watershed, and Cypress Creek Watershed Upstream of US 290," dated
March 2016 and the criteria of another governmental entity that has
regulatory authority over the drainage construction, the more restrictive
criteria shall apply.
(4)
All city drainage criteria not in conflict with this provision
shall remain unchanged unless the city has specifically exempted the
application of this provision to the criteria.
(1999 Code, sec. 9.506; Ordinance 2863 adopted 8/27/18; Ordinance 3032 adopted 4/25/2022)
For uniformity, street signs shall be ordered through the city.
Cost of the signs and erection are the responsibility of the developer.
Signs are required at each street intersection.
(1999 Code, sec. 9.507)
These construction standards are not intended to replace the
regulations of other governmental or private entities whose jurisdiction
includes new subdivisions within the jurisdiction of the city.
(1999 Code, sec. 9.508)