Previously, I characterized the downtown as inconsistently zoned, poorly profiled for investment and renewal, and under-performing in terms of its current zoning. Next, I wrote about the age, quality and safety of the downtown core. There is another issue at hand for Gig Harbor’s downtown (and for all waterfront Puget Sound communities), Condition Three, SLR.
That’s right, sea level rise. Did you know that in light of sea level rise projections the Netherlands is devoting 4% of its national GDP to increase its levee protection.
With 41,526 sq. kilometers, the Netherlands supports a population of just under 16.5 million people, making it one of the most densely populated countries in the world. Rising sea levels could dismantle the Dutch way of life. The people, economy, and property could be decimated, costing the Dutch their livelihood and even their lives. So, the Dutch are well-educated, conservative, and committed to practical action with respect to SLR. The Dutch are raising their levees about 24".
The best action for lowering sea level rise would be a drastic cut in greenhouse gas emissions. Even under the best case scenario, however, the sea level will rise at least 0.4 meters, about 15", at the turn of the century.
In the past, global warming has caused the Earth’s polar regions to be warm for long periods of time. Melting glaciers and polar ice caps 125,000 years ago increased sea levels by 4 to 6 meters. Current earth CO2 level are comparable to those epochs due to man-made causes; it would be best to change the CO2 scenario ASAP.
Recently, the Washington State Department of Ecology stated that Puget Sound sea level rise might reach 22” of sea level rise by 2050, and that doesn’t include the SLR increase due to melting of the Greenland ice sheet, the increase in atmospheric methane due to melting of permafrost, or the possibility of elevation reduction in the Puget Sound Basin due to rapid tectonic shift. The SLR estimate does not address the yearly reality of storm surge and winter high tides.
Given climatic change, how long do you think it will be before the Skansie House basement is full of saltwater? How long will it be before the lower levels of the Harbor History Museum and its archive room will be wet with salt? How long will it be before Harborview Drive, near Java and Clay and the Maritime Inn, looks like waterfront on some days? If you're in high school, then you'll see it!
City planners should institute design requirements that accommodate at least a 40-year high Puget Sound SLR estimate for waterfront projects and adjacent property improvements. Otherwise, public and private construction projects won’t have time to realize a depreciated investment. Even a 40-year high SLR standard may not be enough. To quote a recent WSDOE publication, "If sea level rises 2 feet, a flood event expected to occur once in 100 years would turn into an annual event."
For more information, read this UW study: http://www.cses.washington.edu/db/pdf/moteetalslr579.pdf
The City of Seattle is re-building its seawall along Elliot Bay to a 100-year estimate in this study, an increase of 50". It just goes to show, there are prudent people everywhere.