Climatide

December 2, 2011 | 1:45 PM | By Heather Goldstone

Fixing Falmouth’s sand deficit problem

FILED UNDER: Adaptation, Coast, coastal change

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Falmouth’s south coast is already degraded by development and erosion, and the problem will only get worse as the rate of sea level rise accelerates. Unless …

In their 2003 report to the town, the Coastal Resources Working Group painted a pretty dire picture of the future of Falmouth’s coast under a ‘business as usual’ scenario. And, as I pointed out yesterday, we won’t have to wait for 2100 to see many of their predictions come to life … they already have.

But they also presented an alternative vision (and steps for achieving it) in which the coastal area is largely restored to its natural state and function.

• Beaches and dunes will be wide enough for protection from storms and for public access and use.
• Sufficient sand will reside in the coastal system to maintain those beaches.
• Water quality, habitat and fisheries resources of the coastal zone, estuaries, ponds and marshes will be sustained and enhanced.

Sounds good so far. I mean, who doesn’t want nice big beaches and healthy waters? Now for the hard part …

• A minimum of hard structures (groins, seawalls, etc.) will be found in the coastal zone, to reduce maintenance costs, allow natural sediment transport, and for ease and safety of public use; adverse impacts of their presence will be mitigated by passive and active management approaches.
• Shoreline armoring structures, where present, will not detract from the aesthetics of and access to the shoreline environment.
• Public infrastructure will be removed from the immediate coast to reduce maintenance and repair costs and to reduce its impact on the coastal system.
• A proactive approach to shoreline management will be aimed towards prevention of problems and provide a response protocol when shoreline damage occurs.

This represents some major changes from the status quo. In fact, the authors state outright that, “over the long-term, this amounts to planning for a managed retreat from an advancing sea.”

The Coastal Resources Working Group was made up of some intelligent folks, and they were under no illusions that this would be easy.

Attaining this vision is a serious challenge. In fact, it is unlikely, even in a one hundred year time frame, to expect that the entire south shore will meet all of the criteria of this vision.

…

There are several major impediments to re-establishing a “natural” shoreline in Falmouth. One is private property. Another is public infrastructure.

These are what I would call the social obstacles. Someone (well, hopefully a group of someones) is going to have to make some very tough choices – value judgements – about which homes, roadways, etc. are worth protecting at any (or at least a very high) cost, and which need to be let go for the greater good. While I want those people to do what they have to, I, personally, hope never to be in their shoes.

But beyond the social challenges, Falmouth faces another difficulty of the physical, or perhaps oceanographic, variety. It’s our very own deficit problem – a sand deficit.

The jetties, groins and seawalls, as well as long-term sea-level rise, have robbed Falmouth of much of the sand that made up the beaches of a century ago.

That our beaches have shrunk is obvious. But we’ve also lost something less obvious to the everyday observer – the sand that resides (or should reside) just offshore and feeds the beaches. In addition to our beaches getting narrower, our near-shore waters have actually been getting deeper as hardened coasts push much-needed sand out to sea.

Removing the offending jetties and seawalls is the first step toward reversing the trend. But the report makes it clear that won’t be enough on its own.

Even with the removal of many of these structures, that deficit in sediment must be made up in order to forestall a rapid and unacceptable retreat of the shoreline.

That means adding sand, a process known as beach nourishment. To use a Washington, D.C. analogy: Think of it as the ‘increase revenue’ solution to deficit reduction. And it’s the only solution we’ve got; ‘cut spending’ (a.k.a. erosion) simply isn’t an option. But beach nourishment is expensive. And temporary … particularly if the seawalls and jetties are still there pushing all that expensive sand offshore instead of along the shore.

So there’s a lot of hard work to be done. As with nearly everything, the sooner we get started, the sooner we’ll see results. Still, the Coastal Resources Working Group recognized that the kind of changes needed won’t happen overnight. They laid out recommended actions in three time frames – 0-5 years, 5-20 years, and finally, 20-100 years. It’s been eight years since the report I’ve been citing was issued (a fact I’m sure many of you have realized with some bemusement). I’ve been living in Falmouth all eight of those years and don’t recall seeing many seawalls or jetties dismantled. But, to be fair, most of the actions in the 0-5 year range involve planning, the establishment of committees, the alteration of regulations, that sort of thing. So it’s quite possible that progress has been made, just progress of the less obvious sort. I’ll be checking in with town officials next week to see where Falmouth’s coastal management planning stands … so stay tuned!