Title
Sea Level Rise Response Planning - Update
Recommended Action
Briefing only. No action required.
Report
Issue:
Receive an update on sea level rise planning work initiated by the City of Olympia (City), the Port of Olympia (Port) and LOTT Clean Water Alliance (LOTT).
Previous Sea Rise Items Before the UAC:
City Council has designated the Utility Advisory Committee as the key citizen-appointed committee for reviewing the City’s elements of our sea level rise response plan. The UAC has been briefed on sea rise issues, the planning approach, and progress over the past year and a half. The UAC will be expected to forward recommendations to City Council later this fall.
Staff Contact:
Eric Christensen, Water Resources Engineering and Planning Manager, 360.570.3741
Susan Clark, Senior Planner, 360.753.8321
Presenters:
Eric Christensen and Susan Clark
Background and Analysis:
In early 2017, the City, the Port and LOTT entered into an Interlocal Agreement to jointly fund and participate in a formal sea level rise planning process for downtown Olympia and the Port peninsula. The City, Port and LOTT share common concerns regarding sea level rise, yet have unique individual vulnerabilities. A consulting firm, AECOM Technical Services, is assisting with the planning effort.
Project Tasks and Completion Status
The tasks to be completed by AECOM and the City, Port and LOTT for this project include:
• Evaluate the best available science regarding potential sea rise (Complete).
• Develop a sea level rise planning framework incorporating community input (Complete).
• Conduct a vulnerability and risk assessment of downtown assets (Complete).
• Develop specific strategies for protecting downtown for approximately 100 years. As a component of this task, conceptual drawings for three physical adaptation strategies (Capitol Lake, Percival Landing and Billy Frank Jr. Trail) will be developed. Additional analysis of LOTT and Port specific needs will be provided. (Drafting)
• Complete formal plan including governance needs, implementation schedules, and financing considerations.
The planning process is on schedule for completion later this fall. Considerable information on sea rise and our work to date is available on the City webpage.
The current schedule anticipates the plan will be approved by City Council, the LOTT Clean Water Alliance Board and the Port of Olympia Commission in December and/or January.
Adaptation Strategies
We have a menu of adaptation strategies available to protect downtown. Depending upon the location, more than one adaption strategy may be used and phasing of projects is expected. Included in this menu of options are physical strategies (walls, raised planters) and non-physical strategies (emergency response, updated building codes). Since May, we have been working on linking downtown vulnerabilities with the potential physical adaptation strategies that could be used to protect downtown. For this work, we have delineated Downtown into specific areas:
• Capitol Lake (Lower Deschutes Watershed). The tidal and river dynamics of the lake in association with the low-lying Water Street area create the foremost flooding threat to downtown. Downtown protection efforts need to focus first on the east and north shorelines of the lake. Fortunately, the relatively open landscape adjacent to the lake could accommodate physical adaptation strategies.
• Percival Landing is the second priority. It is physically constrained and under various ownerships. Maintaining or improving the public amenities of the shoreline will be both important and challenging.
• Billy Frank Jr. trail along the East Bay shoreline (Swantown Marina area) is relatively high and when the time comes the shoreline and trail could be raised.
• Port of Olympia peninsula. The Port should be able to complete relatively minor shoreline projects thereby providing protection from flooding for some time. The greatest near-term threat to the Port would be water flowing northerly from downtown Olympia onto the south side of the Port property. With appreciable long-term sea rise, the Port would need to complete substantial protection measures.
• LOTT Clean Water Alliance would need to install various onsite barriers to protect its extensive underground infrastructure - and have confidence that downtown shoreline and stormwater system improvements are completed in a timely manner. The Budd Inlet Treatment Plant will initially be vulnerable to marine water entering the combined sewer system, jeopardizing the plant’s biological health and overwhelming the plant’s capacity.
To develop the potential physical adaptation strategies we:
• Evaluated the physical traits of the current shoreline. The shoreline ranges from crude reinforcements to sophisticated concrete and sheet pile structures.
• Took into account the complex ownership of the shoreline. Key owners include the City, Port, State, and businesses with WA Department of Natural Resources leases.
• Cataloged the various types of physical adaptation strategies available for use.
• Roughly defined the necessary dimensions and layout of the potential physical adaptation strategies.
• Conceptually engineered barriers for the existing shoreline landscape.
• Refined the potential strategies into visual communication tools for community understanding and input.
The proposed physical adaptation strategies developed offer cost-effective, feasible solutions from an engineering perspective. They can be fitted to the downtown landscape. However, we expect refinements and other options to evolve in the years to come, while keeping in mind that construction should begin within 15-20 years.
Targeted Adaptation Strategy Outreach
Staff have also been busy developing communication materials depicting the potential physical adaptation strategies. Our schedule for information sharing is underway and includes the following:
• Various State agencies (e.g., WA Dept of Enterprise Services, DNR and Ecology)
• Downtown shoreline property owners
• Business and environmental organizations
Upcoming Community Outreach
In September, we will present more detailed information on the potential physical adaptation strategies:
• Hosted public shoreline walk, September 8. Self-guided tours available through the month of September.
• Joint elected officials meeting, September 17
• Community meeting, September 19
• Adaptation strategies storymap available on the sea level rise webpage by September 1
The elected officials meeting will also include initial discussions regarding governance and finances. Developing support for sustaining the work in the years and decades to come will be a key outcome of the response plan.
UAC Meeting Format
The August 23 UAC meeting will encompass a walking tour of Percival Landing and Capitol Lake. We will meet at the Olympia Center, Room 103 at 5:40 p.m. for a brief presentation prior to the tour.
Neighborhood/Community Interests (if known):
Various community groups and other agencies are engaged in climate change and sea level rise issues. The City of Olympia Comprehensive Plan and Downtown Strategy support developing a sea level response plan. Citizens voiced their support for the sea level response planning process during several well-attended public meeting conducted over the past several years. Coordination with the City’s regional climate change mitigation planning is also occurring.
Options:
Information only.
Financial Impact:
None at this time. However, potential long-term private and public impacts are appreciable.
Attachments:
• Menu of Strategies
• Current Shoreline Traits
• Capitol Lake Plan View
• Capitol Lake Conceptual Drawings