ITEM TITLE:
Levee Certification and LAMP (Levee Analysis and Mapping Approach) Report
SUBMITTED BY: AnnMarie Lain, CFM Sr. GIS/Planning Technician
FISCAL NOTES:
Expenditure Required: N/A
Unencumbered Balance: N/A
Funding Source: N/A
RECOMMENDATION:
None. Report Only
SUMMARY STATEMENT:
On November 9th, 2016 staff reported to City Council that the City of Valdez submitted to FEMA for levee certification/accreditation for the Lowe River levee system on October 31st, 2016. The process by which FEMA certifies levees is thru a Letter of Map Revision (LOMR). Required submittals include: a) design criteria; b) an operational plan; c) an interior drainage plan; d) a maintenance plan; and e) certified as-built levee plans. Additionally the City is required to provide public notice stating the intent to revise the regulatory floodway. These notices must include the extent of the proposed revision, the changes to the regulatory floodway, and contact information for any interested party. The purpose of this report is to inform City Council members that an individual notice will be sent to all property owners affected by the application for a Letter of Map Revision (LOMR) for levee certification. The public notice will be mailed on March 6th 2017. Attached to this report is a map of the current floodplain boundaries for the Alpine Woods and Nordic Subdivisions as well as a map of the proposed floodplain boundaries.
The proposed changes to the flood zone boundary delineations reduces the amount of parcels located in Flood Zone A and places the majority of the subdivision in Flood Zone B. Whether or not FEMA will accept the proposed flood zone boundary delineations is unknown.
As reported to Council last November, FEMA has funded the Valdez Levee Analysis and Mapping Approach (LAMP) study which will be done on the Lowe River in the four-mile stream reach that is impacted by the levees. If FEMA approves the City of Valdez’s application for a Letter of Map Revision (LOMR), then it is our understanding that the LAMP study will no longer be required.
If FEMA denies the application, then the LAMP study will move forward as planned. The LAMP study is intended to build off of the analysis that was done for the original flood mapping update effort. The analysis will include a natural valley run as well as other runs necessary for the LAMP analysis. It will also include a 2D analysis to determine water flow between the levee segments. The LAMP study, which is entirely funded thru FEMA, will begin work in 2017.
City Council approved the FEMA Levee Seclusion Map study for the Alpine Woods/Nordic Subdivision area on March 1st, 2016. Showing floodplain on the backside of levees has been a challenging area for FEMA. FEMA is currently reevaluating how this is done nationally under what is called a Levee Analysis Mapping Procedure (LAMP). The levee area is secluded from FEMA map updates to allow FEMA time to perform the hydraulic analysis in more detail utilizing the LAMP. The floodplain within the designated secluded area will revert to the current effective floodplain and be updated when the analysis map is completed. This allows FEMA map updates for the remainder of the City to be updated, as a more detailed analysis is pursued for floodplains protected by the levees.
It is staff’s hope that by providing FEMA with an application for a Letter of Map Revision based on a 2D analysis, we can expedite the map revisions for the Alpine Woods and Nordic subdivisions so that homeowners can qualify for a reduced rate flood insurance as quickly as possible.
Staff will continue to update the Council as information becomes available from FEMA.