16
Scenario Planning Workshop Tillamook County Coastal Futures Project
Scenario Planning Workshop
Tillamook County Coastal Futures Project
Scenario Planning Process
Tillamook County Coastal Futures Project Identify System, Develop
Initial Datasets
Develop System Models
Create Scenarios
Evaluate Scenarios
Develop Preferred Scenario
Implement Plan
• Engage you in a discussion with coastal planning/policy experts on current issues, management and policy approaches for coastal planning in Oregon
• Update you on the status of the models used in this project
• Update you on the current understanding of climate impacts on coastal communities in Oregon
• Engage you in a hands-on exercise to begin to define project “scenarios” of future change – focus on “policy options”
Goals for the Workshop…
Tillamook County Coastal Futures Project
Tillamook County Coastal Futures Project
ENV
ISIO
N
Flooding Structures, Infrastructure
Impacted, Economic Value of Structures
Impacted
Economic Costs/Returns Economic Development
Evaluative Models/Metrics Data Sources
Landscape Change Models
Landscape Data •Land Use/Land Cover •Zoning, Population, Structures •Topography, Climate •Many more…
Total Water Level
Policy Sets Stakeholder Engagement
Population Growth Residential Land Supply
Envision Tillamook 2050
Development
Erosion Structures, Infrastructure
Impacted, Economic Value of Structures
Impacted
Tillamook County Coastal Futures Project
What is a total water level?
𝑇𝑊𝐿 = 𝑀𝑆𝐿 + 𝜂𝐴 + 𝜂𝑁𝑇𝑅 + 𝑅
𝑀𝑆𝐿 = mean sea
level 𝜂𝐴 = astronomical
tide 𝜂𝑁𝑇𝑅 = non-tidal
residual 𝑅 = runup, (a function of beach slope, wave height, and wave length)
𝜂𝑁𝑇𝑅
NAVD88 𝑀𝑆𝐿
𝜂𝐴
𝑅 𝑇𝑊𝐿
Tillamook County Coastal Futures Project
Van
Vu
ren
et
al.,
20
11
Climate Change Scenarios
Mid-Century Projection (2010-2045) - Waves
- Dynamically downscaled from Global Climate Models (GCMs) using a mid-level emissions scenario (RCP 4.5)
- Sea Level - High sea level rise scenario,
45 cm increase from 2000-2050 N
RC
, 20
12
Tillamook County Coastal Futures Project
Baseline (Plan Trend) – current plans are captured as closely as possible and played forward
Retreat – emphasizes policies/strategies that move new development away from coastal hazard areas
Defend – emphasizes policies/strategies that supports, “hardens” new and existing development
in hazard areas
Preferred – a composite of the “best” of each of the above scenarios, determined after stakeholder
review
Draft Scenarios
For all scenarios, we will examine at least two climate scenarios representing high and low climate impacts
Tillamook County Coastal Futures Project
Mean Total Water Level
3.9
3.95
4
4.05
4.1
4.15
4.2
4.25
4.3
4.35
4.4
2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
TWL.Mean TWL (m)
Tillamook County Coastal Futures Project
Average Dune Toe Impact Days/Year
0
10
20
30
40
50
60
70
80
90
2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Tillamook County Coastal Futures Project
Number of Flooded Structures
0
50
100
150
200
250
300
350
2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Baseline
Defend
Retreat
Tillamook County Coastal Futures Project
Number of Structures Exposed to Beach Erosion
0
20
40
60
80
100
120
2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Baseline
Defend
Retreat
Tillamook County Coastal Futures Project
Economic Value of Eroded Property ($)
0
5000000
10000000
15000000
20000000
25000000
30000000
35000000
2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Baseline
Defend
Retreat
Tillamook County Coastal Futures Project
0
10
20
30
40
50
60
2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Baseline
Defend
Retreat
Rockaway – Number of Flooded Structures
Tillamook County Coastal Futures Project
Rockaway – Number of Structures Exposed to Beach Erosion
0
5
10
15
20
25
30
35
40
45
50
2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Baseline
Defend
Retreat
Tillamook County Coastal Futures Project
Group Exercise
(e.g. sea level change, population growth)
(e.g. value of flooded structures )
– Identifying “endpoints” that can be used to identify and measure preferable outcomes
• Take a somewhat deeper dive into:
– Drivers of change related to coastal community hazards
– Identifying policies/strategies/actions that should be considered for achieving those outcomes
(e.g. restrict additional development in flood-prone areas)
Tillamook County Coastal Futures Project
Scenario
Retreat Defend
Land Use
Infrastructure
Economic Development
