You are here

Maintain habitat connectivity: Assessment of road-stream crossings

Priority crossings for possible culvert replacement or retrofit are represented by green dots and triangles. If these are not visible, use the plus sign to zoom in. You can layer in locations for the top 5%, 10% and 15% of crossings with the highest restoration potential as estimated by landscape modeling; darker green represents more potential for restoring aquatic connectivity. Green dots are crossings that have been assessed in the field and the potential for restoring aquatic passability is reliable. Green triangles are crossings that have not yet been assessed and the restoration potential is hypothetical. These are high priority crossings for assessment. Data are from the Critical Linkages Phase I (2014).

Hide

Priority crossings for possible culvert replacement or retrofit are represented by green dots and triangles. If these are not visible, use the plus sign to zoom in. You can layer in locations for...

Read More

Adaptation Strategies and Actions

Maintain habitat connectivity: Assessment of road-stream crossings

Adaptation type: 
Monitoring and field assessments
Planning and prioritization
Removal of dams and other barriers to aquatic connectivity
Roadway infrastructure, crossings, and dams
Volunteer involvement

Strategy:

Restore and maintain terrestrial and aquatic connectivity sufficient to maintain healthy ecosystems and wildlife populations

Animal movements (individuals or their offspring) across the landscape are important for maintaining healthy wildlife populations. Climate change is likely to result in changes to habitat conditions (temperature, rainfall, vegetation) that will require many species to adjust the areas they occupy. Restoring and maintaining landscape connectivity sufficient to allow wildlife populations to adjust their distribution over time is a critically important strategy for adapting to climate change.

Action

Assess road-stream crossings for aquatic organism passage
Assessing road-stream crossings

Replacing culverts that block the movement of aquatic organisms (like fish, crayfish, and turtles) is one way to restore river and stream continuity and enhance the resiliency of wetland? and aquatic ecosystems. There are approximately 30,000 mapped stream crossings in Massachusetts and many more that are not mapped. Some culverts are severe barriers to the upstream movement of aquatic organisms; others represent little or no barrier at all, and there are many in between. Without field-based data on the passability of these crossings, it is difficult to identify those sites where culvert replacement would be likely to do the most good.

Tools are now available to assess the passability of road-stream crossings and model their effects on aquatic connectivity. Volunteers and technicians working with state agencies and environmental organizations are using protocols from the North Atlantic Aquatic Connectivity Collaborative (NAACC) to assess the passability of bridges and culverts in the field. These data are used by the University of Massachusetts Amherst, The Nature Conservancy and others to model river and stream networks and identify crossings where upgrades would result in the largest benefits to aquatic connectivity.

Field assessments and passability scores used with landscape-based modeling can help target specific culverts for replacement or retrofit. In areas where crossing assessments have been done, results from landscape models can be used to set priorities for culvert replacement. In other parts of the state where field assessments have not been done, we lack important information about the passability of those structures and cannot effectively prioritize crossings for upgrades or replacement.

About the NAACC

Screen shots of the NAACC web site and digital data form for road-stream crossing assessments.
Screen shots of the NAACC web site and digital data form for road-stream crossing assessments.

The North Atlantic Aquatic Connectivity Collaborative (NAACC) is a network of state and federal agencies, academic institutions, and large and small conservation organizations working together to assess road-stream crossings and support efforts to replace substandard structures and restore aquatic connectivity. The Collaborative is open to all groups who are willing to use the NAACC protocols to conduct assessments of road-stream crossings.

The NAACC relies on local groups made up of lead observers and survey assistants and led by a local coordinator to collect data and enter it into the NAACC online database. To be certified to submit data via the online database, coordinators and lead observers must complete protocol training (in person or online), field training, and shadowing an experienced data collector for 20 assessments. Data are then scored for passability and made available for public viewing and download.

Local groups who collect the data receive the following support from the NAACC.

  • Training and certification
  • Assessment protocols, field data forms, and electronic data collection
  • Landscape models that can assist with prioritizing crossings for assessment, retrofit, or replacement
  • Access to the NAACC online database including bulk uploading for electronic data
  • Immediate access to data and aquatic passability scores
  • A map interface to download assessed and unassessed crossings

If you would like to get involved in the NAACC, see if there are groups participating in your area, or work with others to create your own group, visit http://www.streamcontinuity.org.

Scope and Constraints

Time: 
Ongoing action
Cost: 
Lower cost category
Geographical: 
Parcel-scale
Town-scale
Regional-scale
State-scale
Jurisdictional: 
No jurisdiction required

Goals

National Fish Wildlife Plants Climate Adaptation Strategy Goal 1: Conserve habitat, diversity, and connectivity
National Fish Wildlife Plants Climate Adaptation Strategy Goal 2: Manage species, habitats, ecosystem functions
National Fish Wildlife Plants Climate Adaptation Strategy Goal 7: Reduce non-climate stressors
Forestry Goal 3: Protect rare species and sites
Forestry Goal 5: Re-connect the landscape

My Favorites

Show my favoritesHide my favorites

More info

Bookmark your favorite pages here. See the "add this page link" to add a page to your favorites. Click the X to remove a page from the list.