It's socially and politically tempting to underestimate or downplay the true extent of our physical and economic vulnerability to catastrophic flood damage and loss. After all, if we fully recognized the actual level of flood risk and just how hazardous it is for us individually and collectively, we might have to seriously consider changing our ways. It's human nature to be fearful of and resistant to change.
Vermont, in 2011, experienced three storm events: one each in April, May, and then Tropical Storm Irene in August. Each resulted in state and federal disaster declarations. In strict monetary terms, public expenditures in response to Irene alone is estimated at $733 million. This includes federal, state, local, insured, and private expenditures.
Many consider the 2011 floods, especially Tropical Storm Irene, to represent an extremely rare event. But upon examination of Vermont's history of flooding, it becomes disturbingly obvious that catastrophic, devastating floods occur frequently in Vermont. Emergency and natural resource agencies know that Irene was not an anomaly.
In fact, Irene was the sixth large-scale flood, with a statistically derived return frequency of once every 100 years, to devastate the southern 2/3 of Vermont in 84 years. This represents an actual frequency of a storm like Irene once every 14 years. From 1973 through 2011, Vermont experienced 25 catastrophic floods, each having nearly equaled, equaled, or exceeded the intensity of damages associated with Tropical Storm Irene, varying only in geographic location and scale.
Quantifiable monetary costs, however, do not represent the full costs of floods. Many immeasurable losses degrade the social, economic, and ecological values rivers provide Vermont's communities. Studies have attempted to quantify the myriad ecosystem services that natural systems, including rivers, provide for societal well-being. Rather than attempt to translate these to the monetary tally sheet, suffice it to say that individual and community vulnerability to flood loss functionally converts an infinitely valuable, self-sustaining natural resource to a terrifying, uncontrollable monster that can rip apart our homes, our communities, and threaten our very sense of security.
It's also a tendency of human nature to conclude the cause of conflict, loss, or worse, a disaster, is not our fault but rather the responsibility of some external factor(s). Unrealistic expectations dominate public perspectives of individual and community relationships with fluvial systems. We deny or ignore risk. We believe "the river has always been over there, which is where it belongs." We hold blind faith that flood recovery can restore pre-flood conditions (safety) without re-creating or exacerbating risk.
We rationalize that a devastating flood "won't happen again in my lifetime," and we incorrectly blame some external factor (like not enough river gravel mining) for the loss suffered. But in truth, our vulnerability results directly from our high risk investments in infrastructure and land use that too often tragically conflict with the dynamic nature of rivers. We also sometimes unwittingly increase the risk to ourselves by taking action we think - wrongly - will reduce our exposure.
Many public infrastructure and private property encroachments into historic flow areas of Vermont's rivers depend on maintaining a narrow, channelized, incised and confined stream with little or no flood plain or overbank access. This can result in oftentimes irreconcilable conflict, for which Vermonters may pay the consequences forever. In other words, the choices we made in the past about where to build influence our ability to prevent impacts today. This is the reality of the human condition: we made the best choices we knew then, before we knew better. Now, we have to work around this reality.
This societal relationship with rivers is nothing new. With impunity and without regard for the consequences, we've been usurping all the space in the valley or along the river corridor, building along rivers, and confining rivers with stone. We've done this in deference to our economic and social systems, ever since the time we evolved from hunter-gatherers to an agrarian society. This deeply flawed relationship with rivers, developed through thousands of human generations, seems irrevocably embedded in our collective psyche. But for nearly as long a period of time, rivers, when energized by large storms, have emphatically reclaimed the space we ignorantly took away and, dripping with hubris, figured we need not share.
Unfortunately and distressingly, the most prevalent opportunity to annex even more of the river's space, with intent to confine and constrain rivers to an ever-decreasing proportion of their historic flowage, occurs during flood recovery operations. We dig deeper, incorrectly thinking that will somehow protect us (we know that it doesn't). But, paradoxically, the greatest opportunity to restore a sustainable community relationship with rivers also arises in the post-flood context.
Redefining individual, community and institutional relationships with rivers is possible. A management concept founded on the principle of "dynamic equilibrium" as it relates to the physical nature of fluvial systems makes this achievable.
We are embracing and implementing at all governmental and individual levels a policy of sustaining and restoring dynamic equilibrium in rivers.
We are doing this despite the predominance of irreconcilable conflicts, the lack of supportive federal and state policies, and social resistance to acknowledging the extent, magnitude and source of fluvial conflicts. This approach presents tremendous opportunities not only to accept current realities but also to compel better decisions for the future.
Managing rivers for dynamic equilibrium is composed of two basic elements: First, free rivers from human constraints such as encroachments by buildings; and second, avoid creating new encroachments and confinements, almost without exception.
Through collaboration of state agencies and the Vermont Legislature, a number of initiatives have been enacted. Of greatest promise and potential is the community protection of river corridors from further encroachment. Vermont has established financial incentives for local governments to adopt model river corridor protection ordinances that prohibit new development in defined river corridors.
A companion program that funds and acquires river corridor land use easements preserves forever the land required for rivers to regain and sustain dynamic equilibrium.
River corridor protection complements the Flood Hazard Area regulations that many municipalities have enacted through participation in the National Flood Insurance Program (NFIP). Community safety from flood hazards is enhanced because the NFIP regulations only address flood inundation and do not recognize the fluvial erosion, avulsion, sedimentation, and debris hazards commonly experienced in Vermont.
Monetarily, just how much potential do these river corridor protection programs represent? How much will flood losses and recovery costs be reduced? How much will rivers benefit intrinsically?
It's reasonable to expect that widespread adoption of model river corridor protection ordinances will level off the continually escalating flood disaster costs driven by continued encroachment. For instance, without protecting corridors from new encroachments, the $15 million spent since 2011 on buy-outs of at-risk structures would be, within a few years, more than offset by new unwise, vulnerable, and unregulated investments.
Local ordinances enacted in conjunction with strategic acquisition of river corridor easements preserve the space for confined, threatening, and unstable rivers to re-establish their dynamic equilibrium. In this scenario, vulnerability on a community scale is significantly reduced, disaster costs trend downward, and rivers are restored to the invaluable, sustainable natural resource that is their nature of being. Everyone wins.
Vermont's rivers will recover and heal from these large storms much sooner than Vermont's communities, because the forces of nature provide an infinite and never-ending supply of energy constantly driving the recovery of fluvial systems toward equilibrium. Vermont's communities, on the other hand, largely remain just as vulnerable, oftentimes even more so, than prior to Tropical Storm Irene. Only limited resources, funding, and options exist to resolve the many immediate and irreconcilable conflicts. River corridor restoration and protection contributes to healing the rivers and protecting our homes.
The extent to which Vermont's rivers can sustain and recover dynamic equilibrium is absolutely dependent upon people and communities choosing to be in equilibrium with rivers. It's up to us to give back to rivers, preserving the space they need and restoring them to the infinitely valuable, sustainable natural systems they should be. People and rivers can, and must, share Vermont.
Barry Cahoon, P.E., is River Management Engineer, Vermont Department of Environmental Conservation. To learn more about municipal river corridor protection and river corridor easements, visit: http:// www.vtwaterquality.org/rivers/htm/rv_restoration.htm.