Wednesday, February 10, 2016

Olympia Sea Level Rise Report: An Undeniable Challenge

Above: City of Olympia staff briefed city councilmembers on the implications of sea level rise in downtown Olympia at a study session on Tuesday evening. With a four foot sea level rise, portions of West Bay, all the way to south of Union Street, and the I-5 interchange near Plum and Henderson will be inundated.

Councilmember Gilman Questions Saving Downtown

By Janine Gates

A brutal, sobering report on the implications of sea level rise in downtown Olympia was delivered to Olympia city councilmembers by staff at a study session Tuesday evening. 

Mayor Cheryl Selby and Councilmember Jeannine Roe were excused from the study session and council meeting.

Councilmembers asked questions after the half hour report, but were mostly faced with the undeniable, daunting fact that downtown Olympia is highly vulnerable to sea level rise and has little time to protect itself.

“This year’s work feels a little bit different from past years….We are increasingly concerned and we’re suggesting a more heightened sense of urgency in our response to this dynamic….We feel we are currently vulnerable to flooding downtown and we suggest that the long term implications for what we’ve reported to you are higher than what we’ve reported to you in the past,” said City of Olympia water resources director Andy Haub.

Since the last Ice Age, sea levels have risen more than 400 feet. This process has occurred in spurts, and at times, has risen more than one foot per decade, most likely the result of ice sheets melting. Over the past 5,000 – 7,000 years, sea levels have been stable. The Industrial Age and the use of fossil fuels have accelerated climate change, and in the last 20 years, the rate of sea level rise has nearly doubled that of the previous 100 years.

“….We should develop a vision and a plan to begin adapting to sea level rise sooner than later….We can’t go it alone and we’re only going to be as strong as the weakest link in our defense,” said Eric Christensen, City of Olympia water resources planning and engineering manager.

Staff urged active community engagement, and engineering and financial partnerships with the State of Washington, the Department of Enterprise Services, the Department of Natural Resources, the Port of Olympia, LOTT Clean Water Alliance and the Squaxin Tribe.

Sea level rise information was derived from the UW Climate Impact group and the International Panel of Climate Change (IPCC). The last IPCC report was produced in 2013, however, new information is released on a weekly basis.

According to the IPCC, sea level rise is projected to occur at a rate of 11 to 38 inches by the end of the century. These are global averages, and Christiansen said Olympia’s tides come in 1.28 times higher than Seattle’s.

Adding to sea level rise concerns, according to data via the Washington State Reference Network which monitors land movement, downtown Olympia is subsiding nine tenths of an inch per decade. Monitoring stations are affixed on regional stations throughout the state, and one is located on top of Olympia city hall.

“We have acted very responsibly to date, and we’re in a very admirable position with our knowledge of both Budd Inlet and downtown,” said Haub, who urged that the city create codes for minimum floor elevations for new construction to protect downtown assets. He hopes to propose those this year.

Staff showed several scenarios to illustrate the impacts of sea level rise and climate change in Olympia’s downtown combined with the “nuisance flooding” that already occurs as a result of tidal events. The frequency of this flooding would increase.

Along with a one foot sea level rise, flooding would occur 30 times a year; two feet of sea level rise would flood downtown 160 times a year, and four feet of sea level rise would flood downtown 440 times a year, which is more than once a day.

With a four foot sea level rise, portions of West Bay, all the way south of Union Street,  and the I-5 interchange near Plum and Henderson will be inundated.

Above: High tides of 17.6 feet and low atmospheric pressure created a flooding situation in downtown Olympia on Sylvester Street adjacent to the Oyster House in December 2012.  

The City of Olympia has acknowledged and responded to sea level rise concerns since 1990. Since 2007, staff has been providing city council with annual updates on current climate change and sea level rise research, proposed work plans for addressing sea level rise, and reporting on their accomplishments regarding those plans.

The city set a policy in 2010 to protect downtown and sea level rise is reflected in goals and policies of the city’s 2014 Comprehensive Plan.

Immediately following the report, newly appointed Councilmember Clark Gilman asked how the decision was made to protect downtown and questioned the assumption that it should be saved.

“Looking at the two foot map (indicating sea level rise), you start to see the historical (shoreline)…It’s an interesting choice… To me, downtown is a collection of businesses and public spaces and it could be anywhere within the city limits….My initial gut (reaction) is that, I would much rather invest those resources in creating a more…resilient economy than trying to stop the floodwaters,” he said.

City manager Steve Hall said that the city made its commitment to protect downtown, rather than abandon it, in 2010, adding that a half billion dollars of investments are downtown, most notably the regional LOTT Clean Water Alliance wastewater treatment system.

Councilmember Jessica Bateman asked about Capitol Lake and how its reverting back to an estuary would impact downtown. She also asked about local and regional efforts to reduce greenhouse gas emissions.

“Without the dam, we would currently flood more frequently….the dam definitely helps control flooding downtown,” said Christiansen. He suggested that Heritage Park could be raised to prevent flooding downtown.

Rich Hoey, City of Olympia public works director, said that there will be study session scheduled in July regarding a plan to reduce the city’s greenhouse gas emissions over the next three years. The city adopted an ambitious plan to reduce its greenhouse gas emissions of 80 percent by 2050.

“Quite frankly, we’re going to need regulatory help from higher levels of government to get there….” said Hoey.

Councilmember Jim Cooper said he would like to see the city produce a guidebook of simple adaptations and technical assistance for businesses. He also expressed a desire for downtown buildings to accommodate an eight foot sea level rise, and had concerns regarding the implications of contamination and the ability for underground utilities to deal with sea water inundation.

Cooper also requested that staff model what Olympia would look like if Moxlie Creek were daylighted, and asked if that would help stormwater holding capacity as a functioning estuary. 

Staff said they would look at that scenario. Moxlie Creek is currently 15 – 20 feet below ground, and runs more than a mile through downtown Olympia from Watershed Park to East Bay.

“An incremental adaption, initially preparing for a one to two foot sea level rise - whatever we do - should build the foundation for, and not preclude measures to address four to eight feet of sea level rise,” said Christensen.

Above: The city has 36 stormwater outfalls connected to Budd Inlet and Capitol Lake that are susceptible to backflow flooding. City staff and state Department of Enterprise Services staff prepare for more flooding the afternoon of December 10, 2015 at Capitol Lake in downtown Olympia. Earlier, tides came in 30 inches higher than predicted and caught staff off guard. Water came to within four inches of Olympia Supply's doors. With climate change, El Nino events will become greater in magnitude and flooding will increase in frequency. 

Other planning ideas included elevating the grade of Heritage Park and some roadways, placing planter boxes in strategic locations, and the building flood walls or gates that automatically rise when needed.  A barrier across a waterway, called a barrage, is being used in Venice, Singapore, on the Thames River in England, and the Netherlands.

The city plans to complete ongoing, current capital facility projects, work with the city’s Utility Advisory Committee to develop a multi-year sea level rise response plan, and coordinate its efforts with the council’s Land Use Committee.

Mayor Pro Tem Nathaniel Jones admitted that while progress has been made on data, local agencies do not have the capacity to do the kind of work that needs to be done on this issue.

Coming back around to Councilmember Gilman’s suggestion about abandoning downtown, Jones said the scenario of not making all the investments to protect downtown needs to be on the table and weighed into the overall conversation.

“That alternative is there and it should be respected.”

For past City of Olympia sea level rise reports and high tide events, go to Little Hollywood, and type key words into the search button.