Title
Acting on behalf of County Service Area No. 50 - Rioway Tract:
a. Accept the County Service Area No. 50 Final Lower Carmel River Stormwater Management and Flood Control Report; and
b. Approve the County Service Area No. 50 - Rioway Tract Citizens Advisory Committee recommendation to pursue the Future Conditions/FEMA protection level projects that will meet all applicable standards associated with flood protection measures identified by FEMA to allow for the County Service Area No. 50 - Rioway Tract area to be removed from the 100 - year floodplain and eliminate the need for mandatory flood insurance under the National Flood Insurance Program.
Report
RECOMMENDATION:
It is recommended that the Board of Supervisors acting on behalf of County Service Area No. 50 - Rioway Tract:
a. Accept the County Service Area No. 50 Final Lower Carmel River Stormwater Management and Flood Control Report; and
b. Approve the County Service Area No. 50 - Rioway Tract Citizens Advisory Committee recommendation to pursue the Future Conditions/FEMA protection level projects that will meet all applicable standards associated with flood protection measures identified by FEMA to allow for the County Service Area No. 50 - Rioway Tract area to be removed from the 100 - year floodplain and eliminate the need for mandatory flood insurance under the National Flood Insurance Program.
SUMMARY:
In July 2013, the Board of Supervisors approved an agreement with Balance Hydrologics, Inc. to provide an Updated Final Lower Carmel River Stormwater Management and Flood Control Report for County Service Area No. 50 - Rioway Tract (CSA 50) to provide recommendations for drainage and flood control projects. The recommendations will allow the County to pursue funding and implementation of the interior drainage and perimeter flood control projects necessary to protect CSA 50 from 100 - year floods and remove the area from the 100 - year floodplain.
DISCUSSION:
The County Service Area No. 50 Final Lower Carmel River Stormwater Management and Flood Control Report (Report) analyzes flood risks and hazards within CSA 50 with an emphasis on changes that have occurred since earlier studies were completed. Two (2) levels of flood protection considered include:
Non-FEMA: Project elements at this level would provide reasonable protection against damages from a 100 - year flood event.
FEMA: Project elements at this level would be designed and constructed to meet all applicable standards associated with flood protection measures identified by FEMA. Adherence to FEMA guidelines would allow for the CSA 50 area to be removed from the 100 - year floodplain and eliminate the need for mandatory flood insurance under the National Flood insurance program.
The Summary of Project Cost Estimates Table (Attachment 1) provides a summary of projects based on four different scenario/protection level combinations. At their October 14, 2014 meeting, the CSA 50 Citizens Advisory Committee recommended pursuing the Future Conditions - FEMA scenario/protection level (highlighted projects in Table).
The Future Conditions scenario (considered in the above recommendation) includes two projects outside of the CSA boundary that will result in lower flooding elevations. These projects must also be completed before CSA 50 can meet full FEMA guidelines and be removed from the 100-year floodplain.
Carmel River Floodplain Restoration and Environmental Enhancement Project: The project would restore approximately 120 acres of the south overbank floodplain (commonly referred to as the Odello property). Key project components include removal of nearly all of the existing reengaged floodplain to promote natural systems while maintaining flood conveyance, and providing longitudinal connectivity to the Carmel River Lagoon through construction of a roughly 350 - 500 foot long raised causeway to carry Highway 1 across the overbank floodplain.
Eastern Transition Grading: This critical pinch point was identified just opposite the southeast corner of CSA 50 where a small ridge located on Palo Corona Regional Park land extends to within roughly 150 feet of the main river channel. The construction limits discharge through the area, increases upstream flood elevations, and effectively exposes the entire east side of CSA 50 to increased flood risks. Relatively minor grading and recontouring the ridge area would markedly improve connectivity to the south overbank.
OTHER AGENCY INVOLVEMENT:
The CSA 50 Citizens Advisory Committee supports this recommendation.
FINANCING:
There is no impact to the General Fund. CSA 50 has accumulated funds for flood control purposes since 1967. A grant from the Environmental Protection Agency has been awarded to complete a major portion of the $1.2 million Interior Drainage Project identified in Attachment 1 for Sub - Areas one (1) and three (3) (Stormwater Quality and Drainage). Approximately $450,000 in matching funds will be allocated from CSA 50 and another $125,000 will be allocated from CSA 23 which is entirely within the CSA 50 boundary and collects assessments for storm water drainage. Upon completion of this project approximately $400,000 will remain in the CSA Fund Balance. Property related assessments (approximately $118,000 annually) will continue to be collected and used to leverage grant funding for the remaining three (3) projects identified in this study. Other fund sources, such as a bond measure, will also be explored.
Prepared by: Lynette Redman, Management Analyst III, 831-796-6038
Approved by:
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Robert K, Murdoch, P.E., Director of Public Works
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Carl P. Holm, Acting RMA Director
Dated: April 27, 2015
Attachments: Attachment 1 - Summary of Project Cost Estimates; Attachment 2 - CSA 50 Final Lower Carmel River Stormwater Management and Flood Control Report; Attachment 3 - CSA 50 Final Lower Carmel River Stormwater Management and Flood Control Report FAQ; Location Map (Attachments on file with the Clerk of the Board)