What Are Culverts?

Transportation projects are commonly near, or cross environmentally sensitive areas. For example, small bridges and culverts span rivers and streams, roads divide the landscape while connecting multiple desintations, and trails run through environmentally sensitive areas. In many ways, transportation infrastructure poses a big impact on the natural environment, particularly by causing changes in land cover, forest fragmentation, impacts to water quality, high levels of noise, and increased air polluton, to name a few. More specifically, culvrets and small brdges play a vital role in the transportation network, providing the ability to maintain connections within watersheds, as well as protecting property and other infrastructure from flood, storm damage, and so on. 

Currently there are more than 25,000 culverts and small bridges in the Commonwealth and 5,000 in the Central Massachusetts Region. Many of these structures were built more than 50 years ago and are not only nearing the end of their lifecycle, but they are also undersized regarding changes in current stream flows and design standards. Because of this, many culverts and small bridges pose a threat to roads, infrastructure, and fish and wildlife passage across the Commonwealth and the Central Massachusetts Region. 

According to the Massachusetts Department of Transportation (MassDOT) a culvert is a structure that spans less than 10 feet in length. A small bridge is a structure that spans between 10 to 20 feet in length. Currently, MassDOT provides programs small bridge assessments, for example the Municipal Small Bridge Program. However, MassDOT does not currently have an active program for culverts. Despite this, CMRPC have started to develop a program to assess and identify vulnerable culvert structures in the Central Massachusetts Region.

Assessing Culverts

To help our communities begin approaching culverts in the Central Massachusetts Region, CMRPC has partnered with the North Atlantic Aquatic Connectivity Collaborative (NAACC) to identify, assess, and train individuals on how to assess culverts according to protocols set by the NAACC. Beginning in 2015 as a response to extreme damages due to Hurricane Sandy, funding allowed the University of Massachusetts Amherst to convene a group of experienced people to develop a program (NAACC) and protocols for assessing aquatic passability at road-stream crossings throughout the North Atlantic region. Assessing culverts through NAACC protocols helps to identigy the most vulnerable and criticil culverts that are susceptible to failure during storm events. 

To assess culverts according to NAACC protocol and utilize their scoring system and data center, the individual must be certified by passing specific training requirements. For more information on training requirements please visit click here.

NAACC is in the process of improving its training requirements and more information will be released as appropriate. For more information, please contact Zack Blais, NAACC Regional Coordinator, zblais@cmrpc.org, or Scott Jackson, NAACC Project Leader, sjackson@umext.umass.edu.

NAACC manages a public data of culverts and small bridge structures. To visit, please click here.

Technical Resources and Studies

CMRPC Culvert Assessment Program Hub

CMMPO Water Module: An Introduction to the CMRPC Regional Culvert Program