OLYMPIA - The City of Olympia is rolling out the next phase of its plan to address sea level rise: spending about $75,000 on an engineering analysis of potential sea walls and barriers to keep rising tides out of downtown.
The Olympia City Council will decide tonight whether to pursue the plan for 2010 to 2011.
It would be the latest action in the city’s long-running plan to combat climate change. City staff members cite studies that show that sea levels could rise anywhere from 6 to 50 inches over the next 100 years, due to global warming and melting polar ice.
Officials are particularly worried about worst-case scenarios – when there’s a high tide coupled with heavy rainfall, inundating much of downtown. In addition to the risk of flooding, there’s also concern about saltwater backing up into outfall pipes and bubbling up into downtown.
“It’s our future,” said Andy Haub, planning and engineering manager for the city.
Over the next year, the city plans to hire a coastal engineering firm to look at things such as sea walls, pumps and control devices fitted to outfall pipes to keep saltwater from backflowing into downtown. The work is intended to narrow down solutions. A report is due by this time next year.
“We need to look at maybe a progression of actions to take,” Haub said.
It may not be cheap.
There are no estimates of how much sea walls and other measures would cost. Haub said the next year’s study will result in ballpark estimates, with a wide range.
Public Works Director Michael Mucha said he didn’t know of any other cities in the United States pursuing a seawall strategy. The city is taking a cautious approach.
“As we are trying things and projecting out and figuring this out, we don’t want to lock in too soon on solutions that are costly to the public when we may not get it right,” Mucha said.
Olympia was one of the country’s first cities to address the sea level rise issue, starting with a Global Warming Task Force in 1990. The city’s first focus was on mitigating greenhouse gases. For example, it reduced the city’s emissions to below targets from the 1990 Kyoto treaty by operating greener vehicles. The city also purchases “green power,” a more expensive electricity buy that supports greener forms of electricity production.
In 2008, the city’s efforts turned toward preparing for sea level rise seen as inevitable, Haub said. The City Council allocated $250,000 for work on that issue.
Since then, the city has purchased aerial photography and run computer simulations to look at downtown flooding scenarios, Haub said.
It has also has looked at “subsidence,” a potential phenomenon separate from global warming in which Puget Sound is sinking. And the city is also looking into installing a tidal gauge in Olympia. Haub said the nearest one now is in Tacoma.
The city has about $140,000 left in its sea level rise account. Mucha said that money should last through 2011 and perhaps into 2012.
With the city strapped for cash in the economic downturn, it’s unclear what will be available after that.
Results from the study will also be implemented into the city’s shoreline master plan and comprehensive plan, Haub said, both of which are under review.
Haub puts it this way: “What do we want downtown to look like in 50 years? Do we want to save it or not to save it?”
He was speaking rhetorically. The city intends to save downtown.
“Yes, there’s going to be sea level rise, and we’re going to have to deal with it,” Haub said.