Wednesday, August 31, 2011

Preparing for or Preventing the Next Vermont Flood

Irene has come and gone from Vermont, but we are going to be dealing with her effects for a long time.  Homes and businesses are destroyed, roads and bridges washed out, and people displaced and understandably concerned.

Irene was an 'almost-worst-case-scenario' for Vermont, and hopefully we won't see anything like it again in our lifetimes.  However, floods are a part of Vermont life and we will certainly face other damaging floods in the years to come.  While we can't completely stop them, there are things we can do to decrease their intensity and increase our preparedness when they do occur.

In some ways, reducing flooding in Vermont is harder than in many areas.  Unlike Pittsburgh, with highly urbanized, modified watersheds, or California, with its channelized streams and massive habitat loss, Vermont is a mainly rural state with vast, healthy forests and small towns.  Still, there is much we can do to reduce risk and impact of floods.

This post includes some ideas I have about how to reduce flooding risk, prepare for floods, and better cope when they do occur.  If you think these ideas make sense, please share this with others.  If you think they don't make sense, leave a comment and tell me why.  The most important thing right now, aside from cleanup and repairs, is looking ahead together as a state to make sure nothing like this happens again.

Below are my ideas, in somewhat random order:



Create a High-Tech River, Stream, and Precipitation Monitoring Network

At the current time, there is data from a modest set of river gages available online.  There is also someprecipitation data available at the NWS website, and a few other stations available on Wunderground.com.  These are important, but they aren't enough.  Not surprisingly, most gages are in cities.  But, these can only detect flooding once it is already happening.  We need a system of dozens of creek gaging stations high in watersheds, and a similar number of automated rain gages high in the mountains where most flash floods originate.  The data needs to be available to the general public, ideally through an interactive map, a smartphone compatible site, and perhaps a phone notification service for those who can't or don't want to use the Internet.  The Mad River Watch water quality monitoring website is an example of what it could look like.  Google also has some of this info on their Vermont flooding map.  These sorts of monitoring gages are relatively inexpensive these days, could be partially maintained by volunteers, and could definitely save lives and increase notification time when evacuations are necessary (so no one would have to be stuck in an isolated town for 3 days without enough food).  We have detailed public maps for weather and traffic, why not for what our rivers are doing too?  If the government can't do this, maybe Google or another tech-based group can.

Create a High-Tech Flood Damage Notification Network
Vermont residents are great at helping each other during times of need, but providing them with some extra info could help them do this.  Not surprisingly, Google is already on this too, and has created this amazing map.  We can do more, though, perhaps also through Google.

Locals know when a bridge is about to wash out, when a hillside could give way, when a neighbor is stuck in their home and needs medicine.  During Irene, social networking was useful to many for contacting loved ones and obtaining updates during floods. Again, though, we can do better.  Rather than having to sort through Twitter or Facebook for updates, it would be very helpful to have the info in one place, and associated with a map.  Users would be able to report potential or current issues using a smartphone or the internet or perhaps over the phone, and they would be displayed on a map for others to see.  This could include pre-flood issues (clogged culverts), during-flood issues (flooding as it happens, but stay safe when documenting!) and post-flood issues (road wash-outs and people in need of help).  We don't have to design a system from scratch, either.  There are a lot of websites being developed for non-flood-related reasons that could be adapted to do this.  For instance, check out www.whatsinvasive.com - a site used to report occurrence invasive organisms.  A similar website and smartphone app could easily and cheaply developed to help with floods, blizzards, fires, and other disasters and calamities.

Acknowledge and Prepare for Climate Change
Ok... I am not talking about why the climate changes, or our government's energy policy.  Those are important topics but we'll leave them to another blog.  Instead, let's just all agree that there has been a LOT of extreme weather lately.  Climate can change, dramatically... for instance, 13,000 years ago most of Vermont was under a huge ice sheet.  Right now we appear to be entering a period of extreme storms.    We need to face the terrifying possibility that storms like Irene may happen again in our lifetimes, even though in the past these storms were a once in a lifetime event.  We don't know for sure... and I sure hope it was a one time event... but we need to be prepared in case it isn't.


Manage for Healthy Forests
While dealing with the current flood, there has been reference to older floods, like the New England Flood of 1927 .  That flood dropped similar amounts of rain to Irene but in many cases had much higher water flow.  Why?  Part of the reason may be that in 1927 the forests of Vermont were still recovering from clear cutting and hillside farming in the 1800s, and there was much less mature forest at that time than the current day.  Our forests have recovered since then, which helped keep Irene's floods from being even worse.

Almost all of the water in a river during a flood comes from rain or snowmelt in the river's upper watershed, rather than water that falls directly into a creek or river.  Most of our upper watersheds are forested, mountainous areas.  These mountain forests protect us from floods, so we need to protect them.  This doesn't mean we can't have sustainable logging, but it means we need to make sure logging roads don't unnecessarily increase erosion, make sure to leave enough trees along creeks when logging, avoid additional development and road building in upper watersheds when possible, and work to stop the spread of invasive forest pests and organisms that kill or displace trees, like the Emerald Ash Borer, the Asian Longhorned Beetle, glossy buckthorn, and Morrow's honeysuckle.

Preserve Wetlands and Flood Plains
Otter Creek inundated Rutland with record flows, causing massive destruction.  The water all has to move through Middlebury before leaving the state via Lake Champlain. Yet, the Middlebury area is expecting only minor problems due to high water.  A large part of the reason for this lies in the vast expanses of swamp, floodplain forest, and marsh along the river between Rutland and Middlebury.  These swamps and marshes absorb floodwaters like a sponge and release them slowly.  If we hadn't left these wetlands in place, Middlebury would probably be under water right now, and Virgennes soon would be as well.

Granted, upper mountain streams often are too steep for large swamps (see next section).  But, along our mainstem rivers, maintaining, restoring, and creating wetlands and flood plains will help reduce flooding in the future.

Encourage Beavers
What?  Beavers?  Why?  Because they construct wetlands for us, for free, and in a way that is beneficial to wildlife and waterways on a large scale.  Beaver ponds hold back runoff during floods and release it later, decreasing the peak of flood flows.  Since they thrive along small creeks in upper watersheds, they create wetlands (see above) in places that they would not otherwise exist.  Sometimes beavers build dams in places that cause problems for humans, and they need to be managed.  Installing flow control devices instead of killing the beaver and removing the dam allow for the beavers to still reduce flooding downstream while controlling flooding behind the dam.

Beavers were just being reintroduced to Vermont around the time of the 1927 flood, but were not very abundant yet.  There were essentially no beaver dams or beaver meadows in the Green Mountains.  This probably added to the magnitude of that flood.

Be Wary of Dams
Inevitably after a flood people call for construction of new dams.  This isn't necessarily a good idea.  While some of the large ACOE dams were vital in reducing Irene's flood lows, other dams possibly did more harm than good....

Dams alter the flow and erosion patterns of rivers, and can inhibit the passage of animals (like beavers).  Large dams are massively expensive to build and maintain.  The lakes behind dams become filled with sediment and debris and if not dredged become useless for flood control.  Worse yet, an aging or poorly maintained dam can break during a flood, causing much worse conditions than if the dam weren't built.  There was concern during Irene that the Marshfield Dam would break, inundating Montpelier and other towns along the Winooski River.  This didn't happen, but it could have.

We need to devote sufficient funding to maintaining the dams we have.  If they are unsafe, they need to be repaired or removed.  We should, as much as possible, use 'flood control' dams that only hold water during floods, and allow the land to be used for other things (not habitation/structures!) when not flooded.  We should not use dams as an excuse to build in flood plains.  When we do, the dam operators are not able to release as much water as they should into the river during high water.  Furthermore, we need to look very long and hard at construction of any new dams... and I think in many cases we will find that they just don't make sense, economically OR ecologically

Share Farmland with Water
Water has been making its way into lots of farmfields, homes, and other places where it is unwelcome.  We don't ever want water in homes, but perhaps we should think about setting up a system where rare severe floods are actually 'encouraged' to fill up farm fields.  Perhaps, in fields without structures in them, we should consider removing levees and allowing floods with a 10 or 20 year return interval to flood them.  This would of course have to be accompanied with payment to the farmer for use of his/her land as a flood control area... payment at least as high as the crops they would have lost in the process.  It is sad to lose crops, but rebuilding roads, bridges, homes, and business is much more resource intensive.  Essentially, we should consider creating 'easements' where water is very infrequently stored in fields, and farmers are paid a fair price for the use of their land.

Re-Think Agricultural Drainage
Agricultural drainage systems generally focus on getting water away from fields as fast as possible.  This is understandable, but we also don't want to rush water out of farm areas so fast that it floods villages.  Features like drainage ditches are effective in channeling water, but would still do so, without such a rush of water, if they were a bit wider, less straight, and had some vegetation in them.  Again, if this means the farmer loses some land, let's make sure they are fairly compensated.  Vermont farmers have enough trouble without us adding additional costs.  It's better than subsidizing high fructose corn syrup, right?

Agricultural culverts, when not well-maintained, can also clog, leading to road washouts and erosion.  Let's keep track of our culverts (perhaps using the technology mentioned above) and maintain them properly.  In the case of large culverts, consider replacing them with small bridges that block less water flow and allow animal passage.

Rebuild Appropriately
Vermont's towns and roads are based around our rivers and streams, because they are one of our greatest resources.  I'm not advocating relocating our towns and removing historic structures.  But if historic structures and roads are destroyed by a flood, perhaps we should build the new structures and roads a bit further from the river.  This can sometimes be tricky with how land ownership works, but we can figure something out.  The Kismet restaurant in Montpelier was devastated by floods this May.  The community rallied and the restaurant was repaired and restarted.  Unfortunately, Irene devastated the restaurant again.  This local business is valued by the community and is important to Montpelier, so we should help it stick around.  But let's not put it back in the same building where it will get flooded again. Likewise, a lot of roads keep washing out.  Some roads, like Highway 125 near Ripton, are in narrow gorges and can't be moved... but other roads could be relocated further from the river.  Bridges could be built to allow passage of more water.

Appreciate and Understand our Waterways
The more we appreciate and enjoy our waterways, the more we understand them.  The more we understand them, the more we can anticipate issues, problems, and solutions.  Besides, Vermont rivers and streams are amazing and are one of the best things about the state.  Be familiar with your watershed and local rivers and streams, enjoy them, and make them a part of your life!

Share/Comment on This Post
I like to think these are good ideas.  If you think so too, share these ideas.  They are specific to Vermont but are relevant in other areas too.  If you think I'm off base here, I'd like to know too.  Post something here, or perhaps we can start a thread in a message board for one of the Vermont flood recovery websites.  We need to stick together!


Thanks so much.  I feel very privileged to be a Vermont resident and continue to be touched and awed by the generosity, love, and toughness of Vermonters.  One way or another, we'll make sure we never have to go through something like this again.

No comments:

Post a Comment