AGENDA #5b

MEMORANDUM

TO:                  Mayor and Town Council

FROM:            W. Calvin Horton, Town Manager

SUBJECT:       Revised Town Design Manual and Standard Details

DATE:             January 26, 2004

The attached documents include the latest revisions and updates to the Town Design Manual and Standard Details.  These are staff working documents that supplement and provide detailed information necessary to implement the requirements of the Chapel Hill Land Use Management Ordinance.

BACKGROUND

Town staff developed a formal Design Manual and compiled a set of Standard Details in the early 1980’s, intended to supplement and clarify the Development Ordinance regulations in place at that time.  They were and are “living documents” that must evolve along with changes in development regulations, construction technology, and construction materials.

The Design Manual serves as a handbook for designers.  It specifies means, methods, materials and measurements necessary for development and re-development projects to be constructed in compliance with the Town’s development regulations.  The Standard Details provide graphic illustrations and detailed information regarding facilities and infrastructure that will be acceptable to the Town.

A significant step in the evolution of these documents was necessary when the Council enacted the Chapel Hill Land Use Management Ordinance (LUMO) in January 2003, replacing the Town’s Development Ordinance.  Following adoption of the LUMO, a staff work group was convened to review the requirements of the LUMO and to determine where and how the Design Manual and Standard Details would need to be revised to properly supplement and clarify the new LUMO requirements.

The staff work group began meeting regularly in March of 2003.  The group included key staff from the Engineering, Public Works, Planning, and Inspections Departments.  Over a period of approximately eight months, the work group proposed, discussed and finalized comprehensive revisions in the Design Manual and Standard Details such that they would accurately and fully reflect the applicable requirements of the LUMO.  The revised documents are attached to this report.

DISCUSSION

DESIGN MANUAL

The Design Manual was reformatted to reflect the organization and hierarchy of the LUMO.  The Design Manual focuses on Ordinance Article 5, Design and Development Standards.  Each section of the Manual corresponds to a related section in the Ordinance, and the text is formatted similarly.  We have used the underline and strike-through method of identifying elements of the document that are new, and existing elements that are being deleted.

Stormwater Management

The most significant changes were necessary in Manual Section 2, Stormwater Management.  We added new language to reflect the LUMO requirements concerning stormwater performance criteria relating to total suspended solids, volume, rate and land disturbance.  The Manual was expanded significantly in the areas of acceptable design methodology and criteria.  This includes detailed discussion and information regarding Integrated Management Practices/Best Management Practices, both structural and non-structural.

We have incorporated into the Manual an application submittal checklist for stormwater management materials, including criteria for Stormwater Impact Statements and Stormwater Management Plans that are typically required for new developments.  Unlike the previous document, the revised Design Manual includes detailed illustrations, graphs, and equations to assist the designer in achieving compliance with the Town’s regulations.

Landscaping and Tree Protection

Significant changes were also made in Manual Section 3, Landscaping and Tree Protection with regard to plant selection standards and plant species that are prohibited, restricted, or recommended for use within Chapel Hill’s jurisdiction.  Discussion of pruning, tree protection and critical root zone guidelines have been expanded and now include improved illustrations.

Access and Circulation

Manual Section 4, Access and Circulation was expanded to include subsections devoted to bicycle path design, bicycle lane design, work zone traffic control, and disability access requirements.

Parking and Loading

Manual Section 5, Parking and Loading is an entirely new section providing design guidance for on-street and off-street parking, and for loading areas.

Street Lights, Signs and Markings

Manual Section 6, Street Lights, Signs and Markings is an entirely new section that provides street lighting guidelines and discusses submittal requirements, pole and fixture standards, and sign and marking standards.

Solid Waste Management

Several subsections of Manual Section 8, Solid Waste Management have been revised to properly reflect roll-out collection requirements, residential recycling requirements, and commercial recycling requirements.

STANDARD DETAILS

The Standard Details have changed incrementally over the years in response to new requirements, new technology, and new construction materials and methods.  Recent changes and new details that we have added to the document involve the use of geotextile fabrics and geo-grids as part of street pavement designs, traffic calming devices, reinforced curb-and-gutter sections for bus stop locations, ADA compliant wheelchair ramps, stormwater manhole and catch basin covers with the “Dump No Waste – Drains to Jordan Lake” message included in the casting, subsurface drain alternatives, detention/retention basin designs, bio-retention area design, and stamped-asphalt crosswalk design.

We also maintain a file of supplemental details that were developed for special situations and are not considered to be “standard”.

CONCLUSION

The Design Manual and Standard Details are tools developed by Town staff to assist designers in understanding and complying with the Town’s development regulations and requirements.  We expect to continue making changes in these documents as necessary to achieve those objectives.

We encourage designers and other users of these documents to offer constructive suggestions for improving and updating them as appropriate.  We would also appreciate suggestions from the Council tonight, or at any time, regarding ways we can improve the Design Manual and Standard Details documents.

ATTACHMENT

1.         Design Manual and Standard Details (3-ring binder).