Upzoned — “Are Sponge Cities the Flood Control Fix We Need?”

Podcast: Upzoned
Date: August 27, 2025
Host: Abby Newsham (B)
Guest: John Pattison (C), Strong Towns Community Builder

Episode Overview

This episode dives deep into the concept of “sponge cities,” using Copenhagen as a case study to explore innovative stormwater management strategies that blend engineering with nature. Abby and John discuss how such approaches can bolster urban resilience to climate events, the importance of incrementalism in infrastructure planning, and the broader implications for U.S. and North American contexts. The discussion weaves together practical experience, philosophical perspectives, and lessons from an international model, all through the lens of the Strong Towns movement.

Key Discussion Points & Insights

1. What Is a Sponge City?

(04:36–07:51)

• Inspired by the 2011 Copenhagen flood ($1.8 billion in damages), the city pioneered the “sponge city” approach—a blend of:
  • Nature-based solutions: wetlands, parks, green infrastructure
  • Engineered interventions: underground pipes, retention basins, storage systems
• Aims to absorb, store, and gradually release stormwater instead of simply moving it elsewhere
• The infrastructure often doubles as public amenities: skate parks, amphitheaters, bike shelters

Notable Quote:

"It blends the functionality with other kinds of goals like recreation and design — bike shelters, there's a skate park, an amphitheater — and it all stores stormwater while also being a community asset."
—Abby (06:23)

2. Scaling and Incrementalism: From Citywide to Tactical Approaches

(07:51–13:55)

• John questions the feasibility of citywide, multibillion-dollar projects in other contexts
• Abby offers Kansas City’s (KC) experience: a similar, but smaller-scale, $20M project, which was more practical than the rejected $100M traditional “big pipe” engineering fix
• Emphasizes value of targeting interventions where flooding actually happens, and taking a “test and scale” approach

Key Takeaway:

• Incremental, tactical enhancements can have high impact
• Not every city needs a sweeping transformation—thoughtful, localized projects are often more feasible and effective in the U.S. context

Notable Quote:

"My instinct is that you don't have to make an entire city a sponge city... It's more so an approach that says, where can we make these very incremental tactical enhancements that soak up water where you're actually getting problems..."
—Abby (11:58)

3. Systems Thinking & Redundancy

(13:55–17:03)

• John references permaculture principles: slowing water movement benefits not just flooding prevention but also drought resilience
• Cites Jared Diamond’s story about crop redundancy as a metaphor for distributed, resilient stormwater solutions
• The Copenhagen model leverages redundancy — many small interventions (parks, bioswales, tunnels) for resilience

Notable Quote:

"Above ground there's actually a lot of redundancy...bioswales and parks...so you do have a lot of built in resilience that I think would appeal to many Strong Towns people."
—John (16:23)

4. Solving for Pattern: A Systems-Oriented Philosophy

(18:06–21:13)

• John draws on Wendell Berry’s essay “Solving for Pattern”:
  • Bad solutions fix one problem but harm the greater system
  • Good solutions harmonize with broader patterns—accepting limits, working with what’s at hand, creating multiple benefits
• Praises Copenhagen’s project as a “good solution” by Berry’s standards: addresses water, habitat, air, beauty, social function

Notable Quote:

"One of the things that I do appreciate is it feels like they are solving for a pattern... This project increases water capacity, it freshens the air, it provides habitat for birds and wildflowers. It's beautiful. ... It's going to bring in more parks and skate parks and amphitheaters, and it's good for times of drought as much as times of flood."
—John (20:32)

5. Incremental Fixes vs. Big “Moonshot” Projects

(21:13–24:20)

• Abby explains that KC’s business owners realized small, incremental fixes (reducing flood depth from feet to inches) were preferable to waiting indefinitely for a massive, fully problem-eliminating pipe
• Accumulative benefits of many small projects can be substantial if delivered in a coordinated way

Notable Quote:

"What if you had a whole system of smaller projects that started to combine to cumulatively actually address flooding in a very, very, very meaningful way."
—Abby (23:50)

6. Green vs. Gray Infrastructure: Cost and Maintenance

(24:20–26:44)

• John asks if green infrastructure is cheaper to maintain than gray (concrete/pipe) infrastructure
• Abby: Not definitive, but green infrastructure involves more frequent, iterative maintenance (landscaping, plants); gray infrastructure less often, but potentially costlier when repairs are needed

7. Financial Productivity and Placemaking

(26:44–29:22)

• Places that are already tax-productive merit infrastructure investment
• Infrastructure projects can and should include placemaking to enhance public life—not just functional fixes

Notable Quote:

"You may as well put something back and it may as well be a better street than it was before... take functional aspects of that and make them, you know, community asset builders."
—Abby (28:03)

8. Integrating Expertise for Better Cities

(29:25–30:10)

• Abby advocates for multidisciplinary collaboration (planners, engineers, landscape architects) on projects for maximal benefit

9. Harmony with Nature and the “Genius of the Place”

(30:10–30:32)

• John cites Alexander Pope: “Consult the genius of the place.”
• Both hosts agree that cities should harmonize with natural systems, not fight them

10. Personal and Household-Scale Solutions

(33:25–34:54)

• Abby mentions applying sponge city principles at her own home through stormwater capturing landscaping—encouraging individuals to do what they can at their scale

Memorable Moments & Quotes

• John, on Wendell Berry and “solving for pattern”:
  “He says a good solution accepts given limits, using so far as possible what is at hand... the more far-fetched the solution is, the more it should not be trusted.” (19:22)

• Abby, on incremental change:
  “When you look at this idea and think of it as a citywide project, that is a very different conversation than saying, hey, how can we think about infrastructure differently?” (11:11)

• John, on permaculture:
  "One of the principles of permaculture, to my understanding, is that you don't want water to exit your, the land too quickly." (13:57)

• Abby, on household action:
  “I'm creating my own little sponge city on my lot. Unfortunately, that doesn't mean that my neighbors are doing the same thing. But... there's probably very impactful things that we could do on individual levels...” (34:06)

Timestamps for Important Segments

• [04:36] — Introduction to Sponge City concept and Copenhagen’s experience
• [09:11] — Debate over citywide overhaul vs. incremental approaches; Kansas City’s tactical project example
• [13:55] — Systems thinking: Permaculture, redundancy, and resilience
• [18:06] — Wendell Berry’s “Solving for Pattern” applied to urban infrastructure
• [24:20] — Maintenance and cost of green vs. gray infrastructure
• [26:44] — Financial productivity and placemaking tie-in
• [29:25] — Multidisciplinary teams for better outcomes
• [33:25] — Individual/household-level stormwater solutions

Conclusion: Takeaways & Strong Towns Perspective

• Sponge cities offer hope for communities facing more extreme weather but must be adapted contextually
• Incrementalism and tactical projects can bring major benefits and are philosophically consistent with Strong Towns principles
• The ideal approach “solves for pattern”—fitting infrastructure and placemaking into the larger system of nature, finance, and community
• Everyone, from municipalities to individual homeowners, can participate in making their communities more resilient

Final Thoughts

This episode balances technical, philosophical, and practical discussions to frame the “sponge city” approach as not just an engineering strategy, but a multi-layered, adaptive philosophy for resilient urbanism—one that values harmony with nature, incremental improvements, and the intertwined benefits of infrastructure and place.

For further reading:

• "Sponge City Copenhagen Adapts to a Wetter Future" — Yale e360
• Wendell Berry, “Solving for Pattern”
• Jared Diamond, Collapse

Notable Upcoming Events:

• Chuck Marohn at Kansas City Library’s “Making a Great City” series, Sept 30, 2025

Podcast summary by AI; all timestamps MM:SS.