Title
Consider and take action on an ordinance amending "Chapter 50 of the Code of Ordinances of the City of League City entitled, “Floods” regarding engineering standards for the minimization of flood losses (Executive Director of Development Services)
Background:
Approval of this item will amend Chapter 50 of the Code of Ordinances of the City of League City. This “Flood Ordinance” contains requirements for sub-dividers, developers, applicants, engineers, surveyors, realtors and other persons interested and involved in the subdivision and development of land within areas of the FEMA recognized special flood hazard areas (100-yr floodplain) and within the Zone X (shaded) areas (500-yr floodplain).
This ordinance was last updated in 2022 (Ordinance 2022-26). This amendment provides the following changes: (1) correction of a typo in the definition of Cumulative substantial improvements/damage, (2) a revision to Section 50-66 (Appeals & Variances) to provide details and means related to variances within the 500-year flood, (3) revises Sections 50-81 (General Standards), 50-82 (Specific Standards), 50-84 (Standards for areas of shallow flooding), 50-86 (Coastal high-hazard areas), and 50-87 (Areas between limits of 100-yr flood and 500-yr flood) in relation to the methods used for establishing the finish floor elevation for structures, and (4) creates Section 50-88 (Areas within Flood Zone X).
A further breakdown of these changes are as follows:
• In the 2022 update, the time limit for determining cumulative substantial improvements/damages was modified from 10 years to 5 years. This is seen in Section 50-81(10). Unfortunately, the revision to the definition was missed at that time. This cleans up that discrepancy.
• Section 50-66(a-b) has been revised to allow for additional variance options for structures within the 500-yr floodplain or sometimes referred to as Zone X(Shaded) floodplain.
• In Sections 50-8, 50-82, 50-84, 50-86, and 50-87 the revision is related to how the Finish Floor Elevations (FFE) are calculated. Currently the minimum FFE is the set by the following: 24” above the higher of the base flood elevation (BFE), the crown of the street, or the highest adjacent grade and be a minimum of 3” above the 500-yr water surface elevation. Given our new street design requirements of no more than 9” of ponding water in the street during a 100-yr event and that the highest adjacent grade for new lots are typically only 6.5” above the top of a roadway curb, the need to base FFEs off of the crown of the street or the highest adjacent grade almost never happens. Given the change in size and elevations in the 2019 FEMA FIRMs, the majority of our older areas have BFEs that are at or above the elevation of our existing streets, so new construction in these areas would be governed by the BFE as well. Because of these changes, Staff recommends changing the requirement to reflect FFEs to be a minimum of 24” above the BFE and a minimum of 3” above the 500-yr water surface elevation.
• New Section 50-88 addresses new structures that fall in Flood Zone X, meaning they are outside of the 500-yr floodplain boundaries. This new section will codify the Building Department’s plan to establish FFEs in this area as a minimum of 24” above the highest adjacent grade to the structure.
Staff recommends approval of this amended ordinance.
Attachments:
1. Proposed Ordinance
2. Redline Changes
FUNDING
{X} NOT APPLICABLE