Land, Density and Resilience

Flood-prone areas of south Hampton Roads. Source:

Flood-prone areas of south Hampton Roads. Source: (Click for detail.)

One more takeaway from the Resilient Virginia launch conference yesterday: All other things being equal, more compact communities are more resilient communities.

Like Bacon’s Rebellion, Cooper Martin, program director of the Sustainable Cities Institute, is a big fan of Joe Minicozzi and his maps and graphics showing how dramatically land value-per-acre varies between core urban areas, suburbs and the countryside. Densely settled urban cores have land values that are literally a hundred times higher per acre than low-density shopping centers and large-lot subdivisions.

In my commentary, I have focused mainly upon the fiscal folly of building disconnected, low-density development. The infrastructure — the roads, utilities, sidewalks and other amenities — are more expensive per household to maintain. But Martin added a new dimension when addressing the Resilient Virginia conference yesterday. Low-density development makes it more expensive to harden homes and businesses against disruption and catastrophe. When the taxable value of land is high, it’s easier to support expensive investments to protect that land than when the value of the land is low.

So, to take Hampton Roads, which I have written much about recently, resilience planners need to take into account not only which areas are flood-prone, but which urbanized areas have land values high enough to make them economically justifiable to protect.

It’s going to be gut-wrenching and agonizing, but local officials must come to grips with the reality that much of the development that has taken place is fiscally indefensible. The region cannot possibly afford to protect every low-density subdivision in every flood-prone region — much less the roads and bridges providing connectivity for them — no matter how loudly unhappy homeowners howl at the prospect of being abandoned. The sooner local officials begin making these determinations, the sooner developers will stop building in indefensible areas and the fewer the naive homeowners who will be harmed.

As a practical matter, Hampton Roads municipalities will have to evolve to a pattern of denser development on higher land. Where development exists in flood-prone areas, there will have to be sufficient density to justify spending millions of dollars on protective measures. Fortunately, this is a slow-motion problem. The region has decades to adapt. But it needs to begin now — when complex and painful decisions must be made, decades can slip away in no time at all.