Title
Consider and take action on a resolution authorizing various revisions to the City’s General Design and Construction Standards Manual (Director of Engineering)
Background:
Approval of this item will authorize various revisions to the City’s General Design and Construction Standards Manual. The General Design and Construction Standards Manual consolidates the large majority of typical standards needed for the development or redevelopment in League City and compiles them into a signal location. This manual was first accepted by City Council on September 29, 2011 and has been revised in 2013 and 2017.
The 2018 revision is done in conjunction with revisions to the “Flood Ordinance”. This revision modifies portions of the design requirements in Chapter 6 (“Streets”) and Chapter 7 (“Drainage”) of the General Design and Construction Standards Manual. The intent is for the Ordinance and the Manual to promote and protect the health, safety and general welfare of the public.
This revision is intended to bring certain chapters up to current construction standards, align these standards with requirements noted in the “Flood Ordinance” and to ensure requirements are in-line with the City’s current master plan requirements.
The major revision changes are as follows:
• Sections 602.1.11, 602.5.11, 602.7.11 - Drainage. The current requirement states that drainage inlets cannot be spaced more than 300’ apart on any given street type. This revision adds the requirement that street ponding not exceed 9” in depth when determining the spacing for drainage inlets on specific types of streets. Another requirement is for inlets to be recessed away from the curb gutter line. This will basically offset inlets approximately 2’ from the existing location and remove the “pavement dips” drivers currently feel when driving.
• Street and Road Matrix. This matrix was revised to reflect new requirements for inlet spacing.
• Section 701 - General. The City requires development to follow the Harris County Flood Control District’s Manual for the Design of Flood Control and Drainage Facilities. With this update, we are exceeding some of their standards and the revision to this section notes what exceedances are required (9” street ponding, increase freeboard in detention ponds, overflow requirements, etc.)
• Section 702 - Culverts. This revision increases the minimum pipe diameter from 18” to 24” or the non-circular equivalent to 24”.
• Section 703.1 - Alignment. Currently, a developer can install storm sewer under pavement if desired. This revision would require reinforced concrete pipe (RCP) to be used and require the install a storm sewer closed loop system under the roadway (5’ off centerline).
• Section 703.3 - Inlets. Like the Drainage sections in Chapter 6, this revision adds the requirement that street ponding not exceed 9” in depth when determining the spacing for inlets. It also notes that the inlets are to be recessed away from the curb gutter line.
• Section 704.6 - Inlets. As noted on other sections, this section is revised to denote that the inlets are to be recessed.
Attachments:
1. Data Sheet
2. Proposed Resolution
3. Exhibit A - Revised Manual
4. Redline Changes to Manual
5. Exhibits
FUNDING
{x} NOT APPLICABLE
{ } Funds are available from Account #_____________
{ } Requires Budget Amendment to transfer from Account #_______to Account # _______