Agenda Date: 03/19/2019
Subject:
Title
Resolution 21-2019: Adopting the Urban Drainage and Flood Control District’s Flood Hazard Area Delineation report for Big Dry Creek downstream of County Line Road, dated February 2018
Body
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Presented By: |
Keith Reester, Public Works Director |
POLICY QUESTION:
Does city council support adoption of the Urban Drainage and Flood Control District (UDFCD) Flood Hazard Area Delineation (FHAD) report for Big Dry Creek downstream of County Line Road, dated February 2018?
BACKGROUND:
The floodplain for Big Dry Creek in Littleton was first mapped and shown on Federal Emergency Management Agency (FEMA) Flood Insurance Rate Maps (FIRM) dated December 1, 1978. Littleton has participated in the National Flood Insurance Program (NFIP) since then. Big Dry Creek was again studied as part of an Urban Drainage and Flood Control District FHAD study in 1996, which then became the basis of the FEMA floodplain delineation on the FIRM.
In late 2013, UDFCD began a re-study of Big Dry Creek in light of significant development in the Highlands Ranch area and constructed drainage way improvements since the 1996 FHAD. A new FHAD study was finalized in February 2018 for Big Dry Creek downstream of County Line Road to the South Platte River. A portion of this floodplain is within the Littleton city limits.
Periodically, updates are made to floodplain delineations and regulations, and local governments are required to adopt these revisions in compliance with State floodplain regulations and the NFIP. At the State level, floodplains are regulated by the Colorado Water Conservation Board (CWCB). UDFCD and the CWCB have recently adopted the new study and its floodplain delineation (April 2018 and January 2019, respectively) and have requested the City of Littleton also adopt the new study so the same information is used by all local governments for floodplain regulatory purposes. CWCB floodplains supersede FEMA data when regulating at the local level. FEMA data remains effective for flood insurance purposes in this case. Local adoption is the formal process to identify the regulatory floodplain for purposes of enforcing the city floodplain regulations. FEMA is initiating revisions to the FIRM to reflect this new delineation. Once a new FEMA study is effective, the city must revise the floodplain code (Title 10, Chapter 6) to reference the date of the new FEMA study. This is required to remain in the National Flood Insurance Program (NFIP).
PRIOR ACTIONS OR DISCUSSIONS:
N/A
STAFF ANALYSIS:
Big Dry Creek flows in and out of the Littleton city limits from Littleton Boulevard at the south end to the South Platte River confluence on the northwest end. Currently, there are only a few industrial buildings in the floodplain along Washington Street. In general, this revised floodplain is lower in elevation and smaller in footprint, and those structures appear to no longer be in the floodplain as a result. There are no negative impacts in Littleton associated with this change in floodplain.
In the city’s floodplain regulations, Municipal Code Title 10 Chapter 6 Section 3, the most current flood elevation data is to be used in administering the regulations. Adoption of this study meets the intent of that requirement.
OPTIONS/ALTERNATIVES:
With approval of this resolution, the city remains in compliance and good standing with the State of Colorado floodplain regulations.
If not approved, the city will not be enforcing the floodplain regulations on the best available information for Big Dry Creek. Nor will the city be acknowledging the State regulatory floodplain for Big Dry Creek, a violation of the state floodplain regulations.
FISCAL IMPACTS:
N/A
STAFF RECOMMENDATION:
Staff recommends council adopt the Flood Hazard Area Delineation Report, Big Dry Creek downstream of County Line Road, dated February 2018.
PROPOSED MOTION:
Proposed Motion
I move to approve the resolution adopting the Urban Drainage and Flood Control District Flood Hazard Area Delineation Report, Big Dry Creek downstream of County Line Road, dated February 2018.