To: Board of Supervisors
From: Planning and Building Department
Agenda Section: Departmental
SUBJECT:
title
Status Report on Sea Level Rise Planning Activities by the Planning and Building Department and the Department of Public Works
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RECOMMENDATION(S):
Recommendation
That the Board of Supervisors:
1. Receive the report.
Body
SOURCE OF FUNDING:
The salary funding to prepare this report is included is in the General Fund contribution to the Long Range Planning unit, 1100-282
DISCUSSION:
Sea level rise impacts and how to address them are pressing issues all along California’s coast. A recent article in the Los Angeles Times (Attachment 1) does a good job explaining the complexity and broad scope of some of the impacts of sea level rise. The addition of sea level rise adaptation policies to the county’s Humboldt Bay Area Plan (HBAP) update will be an item for the Board’s consideration in 2020. Several documents have been prepared and workshops held as part of this effort which are described on the county’s HBAP update website: https://.org/1678/Local-Coastal-Plan-Update <https://humboldtgov.org/1678/Local-Coastal-Plan-Update>.
In addition, the Department of Public Works has received $425,000 in Adaptation Planning Grant funding, which together with $55,063 in local match, will be used to develop a sea level rise adaptation plan for the Eureka Slough hydrographic area, a highly vulnerable sub-watershed of Humboldt Bay at the northeast side of the City of Eureka. This plan will be completed in 2020. Additional information regarding this project is available at <https://humboldtgov.org/2487/Sea-Level-Rise>. Public Works is also incorporating sea level rise adaptation measures into the design for the Humboldt Bay Trail South project along the Eureka-Arcata Highway 101 corridor.
Generally, the Humboldt Bay region has many challenges when it comes to addressing sea level rise:
• The region has the highest rate of relative sea level rise on the west coast of the United States due to the combination of rising seas (18 inches in the past century or 0.18 inches per year) and tectonic subsidence.
• The Coastal Commission’s coastal development permit (CDP) jurisdiction within the HBAP is extensive, and the cities of Eureka and Arcata also have land and considerable assets that may be at risk of tidal inundation in the future. A regional approach is the best way to address sea level rise concerns given the impacts shared by each jurisdiction.
• Humboldt Bay has 102 miles of shoreline, 76.7 of which are artificial structures (dikes, railroad grades, fill, fortified natural shoreline, and roadbeds). Of the 56 miles of barrier structures (dike, railroad, road), 33 miles (59%) would be overtopped by one meter of sea level rise and approximately 62% (6,600) of the 10,680 acres of HBAP agricultural land could be inundated if there are no changes to the current shoreline conditions.
• Significant transportation (Highways 101 and 255, access road to King Salmon, Humboldt Bay Trail), utility (water, sewer, electric, gas, fiber optic), recreational (docks, coastal access), environmental (fresh water wetlands, Aleutian goose and other wildlife habitat), marine (north and south jetties, cargo/commercial docks) and cultural (Wiyot sites) assets, and the communities of King Salmon, Fields Landing and Fairhaven/Finntown, could also be inundated by one meter of sea level rise. King tides could reach this level by 2050.
Part of the August 10, 2019 Coastal Commission meeting in Eureka was set aside for sea level rise presentations by local planning consultant Aldaron Laird and Director John Ford that drilled into some of the above issues. During deliberations after the presentations some members of the Coastal Commission expressed support for efforts to create a local joint powers authority to help address some of the concerns. This strategy is described in some detail on pages 24 - 26 of the 2018 policy background study available on the County’s website at the following link: <https://humboldtgov.org/DocumentCenter/View/64596/HBAP-Sea-Level-Rise-Adaptation-Policy-Background-Study-August-2018-PDF>.
FINANCIAL IMPACT:
None for this item, as it is a report only.
STRATEGIC FRAMEWORK:
This action supports your Board’s Strategic Framework by creating opportunities for improved safety and health.
OTHER AGENCY INVOLVEMENT:
Public Works.
ALTERNATIVES TO STAFF RECOMMENDATIONS:
None
ATTACHMENTS:
Attachment 1: Los Angeles Times article: California Against the Sea
PREVIOUS ACTION/REFERRAL:
Board Order No.: C-34 (approval of 2014 grant application); C-16 (approval of 2017 grant)
Meeting of: June 24, 2014; June 13, 2017
File No.: Resolution No. 14-55; Resolution 17-50