Sea Level Rise

in Budd Inlet

South Sound Science SymposiumSeptember 20, 2016

City of Olympia | Capital of Washington State

March 10, 2016 - 17.6 Foot Tide

Olympia’s Setting

Climate Change and SLR in Olympia

• Protect downtown.

• Understand the implications of 50 inches of sea level rise.

• Use opportunities for new public and private investments to prepare for sea rise.

• Seek opportunities to maintain control of valuable shoreline.

City Policy 2010

Sea Level Fluctuations

Global Warming Art project

Post-Glacial Sea Level Rise

Global Warming Art project

Sea Level Trends

IPCC Sea Level Rise Scenarios

IPCC 5th Assessment Report (2013)

Other Sea Level Rise Scenarios

GlobalChange.gov

Sea Level Rise Commitment Beyond 2100

• Carbon emissions through 2015 have committed us to 4 feet of sea level rise.

• Waiting until 2020 to start reducing emissions commits us to almost 8 feet of sea level rise.

• Maintaining current carbon emissions through 2100 commits us to 23 feet of sea level rise.

• Even with climate change limited to 2OC by tough emissions cuts (Paris Agreement), sea levels would rise 16 feet by 2500 and >80 feet by 4015.

Downtown Olympia appears to be subsiding 0.9 in/decade

Vertical Land Movement

http://www.panga.cwu.edu

Flooding is Periodic

Importance of El Nino events

Atmospheric Pressure

NOAA Tacoma real time gage

Key Infrastructure

Current 1% Flood Zone

Elevation 14 feet NAVD88 18 feet MLLW

Affected 55 acres 46 properties 80 buildings 1.7 road miles 122 catch basins

6-inch Sea Level Rise - 1% Flood

Elevation 14.5 feet

NAVD88 18.5 feet MLLW

Affected 108 acres 106 properties 138 buildings 4.1 road miles 161 catch basins

1-foot Sea Level Rise - 1% Flood

Elevation 15 feet NAVD88 19 feet MLLW

Affected 163 acres 188 properties 196 buildings 5.9 road miles 195 catch basins

2-feet Sea Level Rise - 1% Flood

Elevation 16 feet NAVD88 20 feet MLLW

Affected 252 acres 290 properties 269 buildings 8.9 road miles 231 catch basins

4-feet Sea Level Rise - 1% Flood

Elevation 18 feet NAVD88 22 feet MLLW

Affected 368 acres 387 properties 330 buildings 11.4 road miles 269 catch basins

8-feet Sea Level Rise - 1% Flood

Elevation 22 feet NAVD88 26 feet MLLW

Affected 534 acres 586 properties 419 buildings 16.4 road miles 309 catch basins

Shoreline Ownership

Adapting/Protecting

• Elevated/ flood-proofed buildings

• Storm drainage modifications

• Flood barriers

• Elevated landscapes

• Flood walls

• Elevated roadways

• Downtown regrade

• Retreat

Elevated/ Flood-proofed Buildings

New Buildings Existing Buildings

Storm Drainage System

Backflow flooding at Budd Bay Cafe

Stormwater Outfalls

Storm Drainage System

Storm Drainage SystemStorm Drainage System

GREEN SPACE/ TREATMENTOF STORMWATER

DRAINAGE SYSTEMIMPROVEMENTS

DRAINAGE CANAL

PUMP STATION

OUTFALL

USACE

Flood Barriers

Add consolidation map here

Elevate Landscapes

Heritage Park

Planter Box Flood Barriers

Flood Walls

USACE

Elevated Roadways

Downtown Regrade

Seattle Pioneer Square Regrade

Olympia Fill

Retreat

USACE

Sea Level Rise in Budd Inlet

City of Olympia | Capital of Washington State

Eric Christensen

Water Resources Engineering and Planning Manager (360) 570-3741, echriste@ci.olympia.wa.us