– By Natasha Ashenhurst, featured the The Voice Magazine-November 2018
If you want a glimpse of how vulnerable the downtown core of Olympia is to flooding, take a walk along Percival Landing in December at high tide. You’ll see Budd Bay spilling over the boardwalk.
Combine high tide with a storm and the Deschutes River at flood-stage, and downtown Olympia will experience flooding. According to Andy Haub, water resources director for the City of Olympia, downtown has always been vulnerable to flooding because most of it is built on fill excavated from Budd Inlet to create shipping channels.
“We’ve had dramatic floods throughout our history, and the last major one was in the 1970s,” said Haub. “Since then, we’ve managed it very carefully, but we know that downtown’s elevation is simply not high enough.”
What happens when you add a new variable — sea level rise — to an existing problem? We have an untenable situation. Even a moderate amount of sea level rise – six inches — is a problem, let alone some estimates that forecast 32 to 68 inches of sea level rise over the next 80 years.
In order to proactively plan for this looming challenge, the City of Olympia, the Port of Olympia and LOTT Clean Water Alliance joined efforts. The Sea Level Response Plan is a comprehensive strategy for minimizing urban flooding in both the near and long-term and its timeline extends through 2100.
The plan has evolved over the past 26 years from a problem statement into an actionable strategy, complete with specific proposals that are feasible from an engineering perspective. The partners committed in early 2017 to identify stakeholders and actionable steps, create an implementation schedule and set a budget.
The plan partners share similar but unique flooding threats that challenge the services they provide.
The City of Olympia is interested in protecting downtown infrastructure as well as health and safety services.
The Port of Olympia owns extensive shoreline and much of its infrastructure is located downtown, including the Marine Terminal and leased properties — such as the Olympia Farmers Market and the Hands On Children’s Museum.
LOTT Clean Water Alliance’s water treatment facility is located downtown, and much of it is underground and extremely susceptible to flooding and salt water. If saltwater gets into the plant, for example, it would kill off the biological treatment process.
The plan assumes sea level rise of 25 inches by 2050 and up to 68 inches by 2100. Haub admits these are high projections, but they are realistic.
“We can pick lower numbers, but given that this is our downtown, we’ve intentionally picked the high numbers so we can have confidence that we’ll meet the needs of the community.”
For the past decade, the partners have collected information to inform solutions. The most critical data is elevation information.
“We must understand current elevations compared to future elevations,” said Haub. “For example, we know finished floor elevations, street and shoreline elevations, and now we can overlay potential sea-level rise over the top of this.”
This data indicates we will need to increase the elevation of the shoreline and the plan addresses how to do this from an engineering perspective. The other aspect is elevating downtown.
“We require that new buildings downtown are a few feet higher,” said Haub. “When we rebuild Percival Landing, we’ll design for flood protection, and we may need to build roads higher.”
Plan implementation over the next 10 years will be subtle, and many changes are already underway, such as new building codes and installing one-way tide gates. More extensive changes will be a slow process, toward mid-century, but very ambitious.
“Given the scale and the cost and the complexity, it can take many, many years between concept and construction,” said Haub. However, Haub is optimistic that some of the changes will enhance our community design. “If we stick with it we can build a better shoreline as a community amenity. I envision an improved Percival Landing and East Bay Trail system and a waterfront that is linked by trails and paths.”
Haub is optimistic the community will be able to sustain the work already in progress, but he is cautious.
“We have to stick with this plan and stay with this work or else 20 or 30 years down the road we’ll be in a pickle.” said Haub. “Other communities have not started and they could find themselves in panick mode down the line. They ask me where to begin. I tell them to start slowly and to stick with it and soon you’ll have a viable plan.
“Like most large and seemingly impossible tasks, the trick is to simply begin.”