The Unified Development Code (UDC) adopts by reference the City's Specifications Manual.  The Specifications Manual is made up of several documents:  Public Works Design Guide, Technical Specifications, and Standard Construction Details.  The Public Works Design Guide establishes standard principles, criteria, and practices for the design of infrastructure and to protect and preserve the public welfare.  The Technical Specifications identify the specific material, execution, and workmanship requirements of public infrastructure construction projects.  The Standard Construction Details detail (typically graphically) particular installation elements of construction of the infrastructure.  An update of the Design Guide is proposed for a number of reasons and is subject to approval of the City Council in accordance with recent legislative changes to the Texas Local Government Code (LGC).
 
As stated in the UDC, City Council from time to time, on its own motion, or at the recommendation of City staff amend, change, or modify text in any portion of the UDC to establish and maintain stable and desirable development. It is generally considered good practice to periodically review and update the development regulations due to changing conditions, community goals, and/or State and Federal regulations.  The same practice is applicable to design standards adopted by reference in the UDC.  This proposed update to the Design Guide includes a cleanup of typographical errors, and inconsistencies, clarification of vague guidance, coordination with other City documents (such as the Master Thoroughfare Plan), and establishment of increased standards for higher quality, more sustainable infrastructure.

Proposed Amendments:

Section 1 - General
Section 1.1	Clarified applicability of design standards to public and private development.
Section 2 - Required Submission of Plans
Section 2.1.A)	Updated requirements to reflect digital submittals
Section 2.1.B)7)	Added requirement of submittal of engineered plans for retaining walls (relocated from another section)
Section 2.1.B)8)	Added requirement of profiles of 12" water mains (previously only required for 16" and greater mains)
Section 3 - Street Requirements
Section 3.2	Increased pavement design parameters related to loading and structural numbers Removed preference against the use of lime for subgrade stabilization
Section 3.3	Revised specifications (including nomenclature and right of way and pavement widths) to be consistent with Master Thoroughfare Plan Removed provisions related to overhead utilites in alleys
Tables 3.3A, B, C, D, and E	Increased minimum allowable pavement slopes
Section 3.3.C)4)	Added limitation of responsibility of roadway dedication and pavement construction based on limitation of current state statute
Section 3.3.G)2)a)	Added reference to multiuse path (per Master Thoroughfare Plan)
Section 3.3.G)2)c) and 3.3.H)1)	Increased strength of concrete for sidewalks and alleys
Section 3.4.D)	Removed reference to geogrid for use as a mitigation technique for soils with high plasticity
Table 3.4.A	Removed reference to geogrid for use as a mitigation technique for soils with high plasticity
Section 4 – Storm Drainage Requirements
Section 4	Removed reference to City-maintained hydrologic and hydraulic models
Section 4.1.A)	Clarified design frequency requirements
Section 4.1.F)	Added explicit requirement for stormwater discharge to mimic existing or predeveloped flow characteristics so as to not cause adverse impact to downstream property
Section 4.4.A)	Added stronger encouragement of provision for post construction water quality BMPs and requirement of consideration for future retrofit of facility to meet future water quality standards
Section 4.5.A)1)	Added statement disallowing use of Modified Rational Method for computing stormwater runoff
Section 4.5.A)2)	Reduced size of drainage area considered “small” from 200 acres to 50 acres and disallowed use of Rational Method for peak flow calculation if time of concentration is greater than 20 minutes
Section 4.5.B)1)	Specified minimum total time of concentration as 5 minutes
Section 4.5.B)1)a)	Reduced maximum distance allowable for time of sheet flow in time of concentration calculations from 300 feet to 100 feet
Section 4.5.D)	Adopted NOAA Atlas 14 precipitation frequency data for stormwater runoff calculations
Section 4.5.G)5)b)	Increased design loading of crossings, culverts, and bridges to HS-25
Section 4.5E)	Increased freeboard depth required for channels between 5- and 10-foot depth
Section 4.5.H)9)b)	Decreased allowable earthen channel side slopes from 3:1 to 4:1
Section 4.5.H)8)e)	Decreased channel side slope allowance for railing to be required from 2:1 to 3:1 (for channel depths greater than 2 feet)
Section 4.5.I)2)	Added requirement of access manholes at all storm sewer junctions
Section 4.5.K)1)	Added control of 2-year frequency event to detention facility design
Section 4.5.K)9)	Added additional criteria that must be met in order for the consideration of a detention facility with a permanent wet pool
Section 4.5.L)	Added requirement for the provision of adequate space for the transition of flow from a drainage outfall to predevelopment conditions prior to leaving property
Section 5 – Sanitary Sewer Requirements
Section 5.2.A)	Increased design loading of manholes to HS-25
Section 5.2.G)7)	Added requirement of property line cleanout on all laterals (aligning with previously updated Standard Construction Detail) and removed reference to cleanouts otherwise used on public mains
Section 5.2.G)8)	Added requirement for sampling port on all non-residential laterals
Section 5.2.G)13)	Updated requirement for flowable fill to encapsulate all manholes (aligning with previously updated Standard Construction Detail)
Section 5.3.B)4)	Clarified waiting period prior to deflection testing after final backfill and/or pavement construction
Section 6 – Water Requirements
Section 6.2.A01)a)	Reduced distance required between fire hydrant and structure from 500’ to 400’ or as required by the Fire Marshal
Section 6.2.A)4)	Added section related to private fire lines limiting length of single connection to public main to 1000’ and citing references for design criteria and construction specifications
Section 6.2.B)2)	Clarified requirement for construction of cross-connecting supply and distribution mains including those on the water master plans and where distance to dearest mains exceeds minimum
Section 6.2.B)5)	Added Prohibition of combined domestic and fire service lines for private facilities
Section 6.3.B)1)	Added default requirement for encasement of pipe beneath commercial driveways with provision for exception based on certain considerations
Section 6.3.B)2)	Added requirement for encasement of mains crossing thoroughfare roadways
Section 6.3.D)2)	Added prohibition of domestic connection to dead end mains and clarified looping requirement
Section 6.3.F)	Added storz connection to fire hydrant specification (in alignment with previously updated Standard Construction Detail)
Section 6.3.J)	Added requirements and standards for replacement of asbestos cement (AC) pipe when new connection is being made or where cover is decreased over an existing AC main
Section 7 – Inspections and Testing
Section 7.1.F)1) and 2)	Increased testing frequency for street subgrade and base
Section 7.1.G)	Updated infrastructure acceptance submittal requirements to specify only digital formats and specified that asset locations must be surveyed
Section 7.1.H)	Brought into alignment with UDC by citing two-year warranty period for public improvements

Staff suggests use of the same evaluation criteria in UDC Section 21.4.7.D. typically used for the evaluation of UDC text amendments.

1.  The proposed amendment promotes the health, safety, or general welfare of the City and the safe, orderly, efficient and healthful development of the City.
In order to promote orderly, efficient, and sustainable development, construction design standards should be reviewed and updated from time to time based on improved industry standards, technologic advances, the City's maintenance capabilities and growing body of experience.  Also, to promote health and general welfare, the establishment of clear guidelines and standards for well-designed and constructed infrastructure systems is essential. 

2.  An amendment to the text is consistent with other policies of the UDC and the City.
These amendments to the Design Guide will help align it with the UDC, other plans in the city, such as the Master Thoroughfare Plan, and other parts of the Public Works Specification Manual.  Also, one of the stated goals in the UDC is to "facilitate the adequate and efficient provision of transportation, water, wastewater, schools, parks, public safety and recreational facilities, and other public facilities and services". These amendments will help achieve this goal.

3.  Any proposed amendment is consistent with the goals and objectives of the UDC and the City.
The City's recently adopted Strategic Plan also highlights the city's goals and objectives. Among these are Sustainable Government, Safe and Livable Community, and Infrastructure Investment.  Maintaining an up-to-date Public Works Design Guide with clear, appropriate standards established to promote high quality, sustainable infrastructure is critical to the health, safety, and welfare of the community.  These amendments would achieve these goals and policy values in the Strategic Plan.

4. Other criteria which, at the discretion of the Planning and Zoning Commission and the City Council, are deemed relevant and important in the consideration of the amendment.
The scheduled public hearing provides the opportunity for the Planning and Zoning commission to determine this.  

For these reasons, staff recommends approval of PLUDC20240243.

The Planning and Zoning Commission in making a recommendation to City Council on the proposed Amendments to the Public Works Design Guide.  In considering action on a document incorporated in the UDC by reference, the Commission should consider the criteria within UDC, Section 21.4.7 D.