Case Studies: Dynamic Adaptive Policy Pathways

Lecture

James Doss-Gollin

Monday, April 13, 2026

Background and Context

Today

1. Background and Context

2. Room for the River

3. Current Debates

4. Dynamic Adaptive Policy Pathways

5. Wrap-up and Connecting

Target: 1:00. Part 1: ~10 min.

The Netherlands

Figure 1: Flood-prone zones (blue) and key flood defense infrastructure. Source: M. Haasnoot et al. (2020).

Target: 1:02. Orient students. Dark blue = below sea level. Light blue = flood-prone from rivers. Note the dike rings and storm surge barriers marked on the map.

A Long History of Flooding

The Dutch have been fighting water for centuries.

• 1404, 1421: St. Elizabeth Floods reshape the coastline
• 1530, 1570: Catastrophic North Sea floods kill tens of thousands
• 1916: Zuider Zee flood triggers first modern flood protection program
• 1928-1943: Repeated studies find dikes “seriously defective” — repairs delayed by WWII

Then came 1953.

Target: 1:04. The point: 1953 wasn’t a surprise. Warnings went back decades. WWII, competing priorities, and years without major flooding reduced urgency. Source: MIT.

February 1, 1953

Figure 2: Aerial view of flooding in the Netherlands, 1953. Source: Wikimedia Commons (public domain).

Target: 1:06. Let the image sit. 1,836 dead. 72,000 evacuated. 200,000 hectares flooded. Dikes breached in 150+ locations.

“Never Again”

The 1953 disaster reshaped Dutch politics.

• The Delta Commission was formed within weeks
• Parliament committed to a 1-in-10,000 year protection standard for critical infrastructure
• The result: a 40-year, multi-billion euro construction program

Target: 1:08. Failure floods the Randstad (Amsterdam, Rotterdam, The Hague). Political commitment, not just engineering.

The Delta Works

Figure 3: The Maeslantkering storm surge barrier. Source: Wikimedia Commons / Rens Jacobs (CC BY-SA).

Target: 1:09. Maeslantkering = one of the largest moving structures on Earth. 40 years, billions of euros. 1-in-10,000 year design standard.

Think-Pair-Share (90 seconds)

It’s 2026. You’re advising the Dutch government on whether the Delta Works are still adequate.

Using what you’ve learned in this course, what questions would you ask?

Target: 1:12. 60s think, 30s pair, cold-call 2-3. Open-ended on purpose — let students generate the concerns from course material. Don’t resolve. Collect answers, then transition to the video.

Room for the River

Today

1. Background and Context

2. Room for the River

3. Current Debates

4. Dynamic Adaptive Policy Pathways

5. Wrap-up and Connecting

Target: 1:14.

A Different Kind of Response

The Delta Works said: hold the line.

Starting in 2006, the Dutch tried something different.

Instead of raising dikes higher, they asked: what if we give the river more room?

Target: 1:15. One sentence, then play.

Room for the River

Target: 1:23. 8-min video. No interruption. Pause briefly after.

Current Debates

Today

1. Background and Context

2. Room for the River

3. Current Debates

4. Dynamic Adaptive Policy Pathways

5. Wrap-up and Connecting

Target: 1:23. Part 3: ~12 min.

The Problem with “Predict-Then-Act”

Traditional approach:

1. Make best forecast
2. Design optimal solution
3. Build it and hope

(is this a straw man? yes.)

Problems:

• Brittle: Optimal for one future, fails in others
• Divisive: Stakeholders disagree on which forecast to use
• Static: Hard to change course as you learn more
• Vulnerable: Fails catastrophically when surprised

Target: 1:25. The Delta Works = textbook predict-then-act.

Hold the Line vs. Adapt with Nature

Hold the Line

• Hard engineering: higher dikes, stronger barriers
• Protect existing land use and development
• Proven track record, measurable standards
• Clear design criteria and accountability

Adapt with Nature

• Nature-based solutions, managed retreat
• Work with natural processes
• Multiple co-benefits (ecosystem services, recreation, equity)
• Flexibility across uncertain futures

Neither is obviously right. Real solutions likely involve both – but the balance depends on values, not just science.

Target: 1:28. The Dutch kept the Delta Works AND added Room for the River. They didn’t choose one side.

How the Dutch Actually Decided

The Delta Programme faced a choice you’ve seen before:

For individual structures:

• Probabilistic design standards.
• 1-in-10,000 year return periods.

For long-term strategy:

• Scenarios, not probabilities.
• Four Delta Scenarios exploring divergent futures.

They used both — probabilities where they could, scenarios where they couldn’t.

Target: 1:31. Four Delta Scenarios (Warm, Rest, Busy, Steam) without probabilities. Individual structures still use probabilistic standards. Both coexist.

Think-Pair-Share (90 seconds)

Which side of the “Hold the Line vs. Adapt with Nature” debate does the Room for the River video support?

What’s the strongest argument for the OTHER side?

Target: 1:34. 60s think, 30s pair, cold-call 2-3. Push students to steelman the side they disagree with.

Dynamic Adaptive Policy Pathways

Today

1. Background and Context

2. Room for the River

3. Current Debates

4. Dynamic Adaptive Policy Pathways

5. Wrap-up and Connecting

Target: 1:34. Part 4: ~8 min.

Adaptation Tipping Points

An Adaptation Tipping Point (ATP) is the condition under which a strategy no longer meets its objectives.

Examples:

• Storm surge barrier effective up to 2.5m sea-level rise
• Current evacuation plan works for population < 150,000
• Nature-based solutions sufficient for rainfall < 150 mm/day

ATPs tell us when we need to adapt, not just what to adapt to.

Target: 1:37. ATPs bridge scenario discovery (Week 10) and sequential decisions (Week 11). Numbers are illustrative.

The Key Insight

There is no single “optimal” plan under deep uncertainty.

Instead: design pathways — sequences of actions that can be adjusted as we learn.

A pathway is a sequence of decisions where transitions are triggered by observable conditions.

Target: 1:39. Triggers must be observable, not predicted.

The Pathway Map

Figure 4: Adaptation pathways map for water management in the Netherlands. Source: Marjolijn Haasnoot et al. (2013).

Target: 1:42. Walk through the figure: x-axis = time. Colored lines = adaptation options. Circles = transfer stations. Vertical bars = ATPs. Bottom rows = two scenarios. The map IS the plan.

What Makes Pathways Different

Traditional Approach	Adaptive Pathways
Optimize for one scenario	Perform under many scenarios
Static plan	Triggers for adaptation
Single recommendation	Menu of options
Uncertainty as risk	Uncertainty as driver of design

Target: 1:44. Bottom row is key: uncertainty drives the design, not just the analysis.

Wrap-up and Connecting

Today

1. Background and Context

2. Room for the River

3. Current Debates

4. Dynamic Adaptive Policy Pathways

5. Wrap-up and Connecting

Target: 1:44. Part 5: ~6 min.

Write (60 seconds)

Trace your final project through this pipeline.

Which stages did you use? Which didn’t you need? Where did you spend the most time?

Target: 1:49. 60s silence. Then cold-call 2-3.

Five Questions for Any Case Study

1. Decision context: Who decides? What’s at stake? What are the constraints?
2. System model: What’s captured? What’s left out?
3. Uncertainty characterization: Deep or well-characterized? How sampled?
4. Decision framework: Static or adaptive? Single or multi-objective?
5. Limits: What does this analysis NOT answer?

Target: 1:49. Scaffold for Wednesday. Question 5 is the most revealing.

This Week and Next

• Wednesday: Dongwook leads discussion of Steinschneider et al. (2015)
• Friday, Apr 17: No lab; you are encouraged to use the time to practice your final presentation
• Week 14 (Apr 20-24): Final presentations

References

Haasnoot, Marjolijn, Kwakkel, J. H., Walker, W. E., & ter Maat, J. (2013). Dynamic adaptive policy pathways: A method for crafting robust decisions for a deeply uncertain world. Global Environmental Change, 23(2), 485–498. https://doi.org/10.1016/j.gloenvcha.2012.12.006

Haasnoot, M., Kwadijk, J., Alphen, J. van, Bars, D. L., Hurk, B. van den, Diermanse, F., et al. (2020). Adaptation to uncertain sea-level rise: How uncertainty in Antarctic mass-loss impacts the coastal adaptation strategy of the Netherlands. Environmental Research Letters, 15(3), 034007. https://doi.org/10.1088/1748-9326/ab666c

Steinschneider, S., McCrary, R., Wi, S., Mulligan, K., Mearns, L. O., & Brown, C. M. (2015). Expanded decision-scaling framework to select robust long-term water-system plans under hydroclimatic uncertainties. Journal of Water Resources Planning and Management, 141(11). https://doi.org/10.1061/(asce)wr.1943-5452.0000536