Olympia City Hall

Olympia addresses Sea Level Rise Response Plan

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OLYMPIA –– Olympia city officials met Thursday evening to discuss its role in handling concerns of rising sea levels, an aspect of climate change that can significantly affect cities near the nation’s coastline.  The jurisdictions of LOTT (Lacey, Olympia, Tumwater and unincorporated Thurston County) have worked together to formulate a long-term plan of action.

“This was a unique effort across [multiple] jurisdictions. The planning effort concluded in 2019 and resulted in the adoption of the Olympia Sea Level Rise Response Plan,” said Eric Christensen, Olympia’s Water Resources Director. “The plan addresses climate science and sea level rise projections...as well as vulnerability.”

According to Christensen, downtown Olympia is vulnerable to extensive flooding due to its proximity to the waterfront, as well as its low-lying areas.

“The plan proposes a phased approach to adaptation with investments being made at the appropriate time,” said Christensen. “Phases are in six-inch, 24-inch and 68-inch increments [of sea level rise].”

Of course, downtown Olympia serves as a cultural and economic hub of the region. The danger of flooding is nothing new, but is increased by a changing climate. The region has always been susceptible to flooding, Christensen said.

“The confluence of high levels in Capitol Lake or high flows in the Deschutes River combined with high tides can cause water to overtop the shoreline, particularly in Heritage Park, and spill into downtown streets and low-lying areas, even with normal amounts of sea level rise,” explained Christensen. “The risk to downtown’s built environment and its many community services increases quickly and substantially.”

The city has already implemented some specific measures. LOTT and the Washington State Department of Enterprise Services have been coordinating regularly on emergency operations related to downtown flooding.

“The focus has been on sandbag placement locations and the ways to prevent floodwater from entering the combined sewer system and jeopardizing the capacity of the treatment plant,” said Christensen. “The city has also installed 20 tide gates to prevent water from flowing in reverse back up pipes from Capitol Lake and marine waters and flooding low-lying areas of downtown.”

Sea level rise has made its way into draft wastewater considerations.

“The city’s also integrated sea level rise into its draft wastewater management plan, and we took sea level rise into account in the recent design for the relocation of our old port – the station,” said Christensen.

One of the greatest challenges with undergoing the plan is the uncertainty that sea level rise creates. Measuring the exact amount of increase, which is a number that can oscillate from time to time, can become more complicated than it may seem. According to Christensen, a phenomenon known as Pacific Decadal Oscillation plays a role.

“This is an oscillation in sea levels between the north and south Pacific. Over the last approximately 15 years, this has been fairly stable,” he explained. “And the north Pacific hasn’t seen nearly the sea level rise that the south Pacific has, but data collected over the last 170 years from tidal gauges indicate that this could change pretty rapidly in the next year or two, and we could see several inches more sea level rise in a short period of time.”

Additionally, the process can feel abstract and a bit messy due to its intangibility.

“Sea level rise is of course uncertain. Our response will need to be based on reality, so investments and adaptation are reasonable and justified,” continued Christensen. “Relative sea levels in the Puget Sound region have risen approximately two-and-a-half inches since 1990, but land subsidence in Olympia could mean that we have seen up to four inches of sea level rise.”

Another challenge revolves around the way the agreement is set up between related parties. Officials have had to figure out the layout of the official governmental structure, parse out how many representatives and votes each party should have, and determine exactly which partners will be involved.

“A citizen/stakeholder advisory group could be considered,” said Christensen. “Olympia is the only entity currently in the interlocal [agreement] that has dedicated sea level rise funding available, however.”

The city hopes to further its communication with the public to address concerns and establish a better understanding of the issue. 

Citizens can directly inquire about the issue with Olympia city officials through an email account which is tended to on a regular basis.

“The city continues to maintain a sea level rise website which we update regularly, and we also maintain an email account dedicated to answering questions and concerns [regarding] sea level rise,” explained Christensen. “And not just the community. We get a lot of email nationwide.”

To learn more about Olympia’s role regarding the issue of sea level rise you can visit their website here, or email searise@ci.olympia.wa.us.

Olympia City Hall, Olympia City Council, Sea Level Rise Response Plan, Eric Christensen, Olympia Water Resources Director, LOTT, flooding, sea level rise

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