This commentary is by Frank Seawright. He has lived in Windham for 23 years and is an experienced amateur cartographer.
As Vermonters prepare for future flooding events, a humble human invention — the culvert — has rapidly risen in prominence for those responsible for our town roads. In fact, it might be argued that culverts, properly sized and maintained, are at the very top of the list of reliable safeguards for flood-prone areas.
If you haven’t stopped to consider the crucial role that culverts play in protecting your roads from washouts, maybe it’s because you haven’t been flooded recently. Even so, you might think that, given culverts’ centrality in preventing costly road destruction, both the state and towns would be assiduous in monitoring and maintaining all of Vermont’s culverts, as well as in upsizing culverts whose too-small diameters have failed to protect roads from rampaging runoff during previous rains. Unfortunately, you’d be wrong.
In 2005 the Vermont Legislature directed the Vermont Agency of Transportation to create and maintain a database of culverts in Vermont. Those data are available at www.vtculverts.org.
I have been unable to find the exact language of the directive, but I have learned an interesting fact about funding for culvert maintenance from the state’s Flood Ready Vermont website. It tells us: “To qualify for a Town Highway Structures grant the community must have an inventory of highway infrastructure not more than three years old. The inventory should identify all town culverts, bridges, and known road problems. The inventory includes the location, size, deficiency/condition, and estimated cost of repair (where the condition is less than acceptable).” So if your town expects help paying for flood damage, you’d better know where your culverts are and what shape they are in. In other words, you need a complete culvert inventory.
From thinking far too much, some might even say obsessing, about culvert inventories for the past several months I have determined a few important things: the “vtculverts” data mentioned above are geospatial, meaning that these data can be accurately positioned on a map using a geographic information system (GIS); I have come to believe that every town needs in-house expertise with GIS because mapping data allows us to see things we might otherwise miss, in this case, culverts; most importantly, I have discovered that some towns inventory at least some “private” culverts and others do not inventory any.
Now what is a “private culvert” you might ask, and do I have one? Well, you probably do if your driveway ends in a road that has ditches along its sides to contain water runoff. So your culvert, should there be flooding, will be either part of the problem or part of the solution. Whether towns are required to include your culvert in the town inventory is unclear, since nobody seems able to find the language of the original state directive to VTrans. It seems likely that many towns have not included their private culverts in town culvert inventories.
In my town of Windham, for example, our densest housing (on Timber Ridge, a now-closed ski enterprise) is also situated at our highest elevation. A large part of the terrain there drains north, sending water over a state road. On August 3, 2003 a flash flood damaged this state road so badly that it was closed for repairs for nearly a year. I recall that our municipal taxes were raised so we could pay our share of the cost of repair. But the private culverts on Timber Ridge, which should have helped protect the road, are not part of Windham’s culvert inventory.
I found agreement from the folks at Flood Ready Vermont that private culverts are a problem. According to one person with whom I corresponded, these culverts “…are often under-sized, poorly maintained, and frequently contribute to public road damage.” But, alas, Flood Ready Vermont does not have regulatory power. Any improvement can come only through town initiative.
What can towns do to have all culverts included in the inventory? One option would be an article for Town Meeting allowing voters to decide whether to require that all culverts — both public- and town-owned, and private — be inventoried and evaluated. Another avenue would be for town leaders to ask for community support in improving flood readiness: they might distribute an inventory checklist that each homeowner can complete, with the resulting data to be included in the town inventory. In addition, given that nearly everyone has a cell phone, the town could ask residents to take pictures, which are geotagged with location data, to document how culverts perform during rain storms.
It is imperative that we create and maintain a complete inventory to inform future flood preparedness. Because replacing a culvert is costly, towns should explore financial aid for property owners, or decide whether it’s cheaper for the town to replace critical private culverts rather than risk more costly road repairs later. However we do it, we need to recognize the central roles our culverts play in protecting our roads from flooding, and make sure we maximize their protective potential.
Read the story on VTDigger here: Frank Seawright: The importance of mapping culverts in Vermont towns.