Of Bats, Bridges, Culverts: Part 2

As the Texas Department of Transportation works its way through a three-year study to determine why bats make their homes in certain types roadway bridges and culverts, other states are engaging in similar bat-preservation endeavors as well – especially in terms of mitigating the impact of bridge demolition and construction activity on bat populations.

For example, the southern region of New Mexico is home to year-round bat activity and Jim Hirsch, District 4 environmental analyst with the New Mexico Department of Transportation, said bats commonly hang out under bridges that span perennial waterways, such as the Rio Grande and Pecos rivers. 

Top photo by Diane Winterboer for the U.S. Dept. Of Agriculture/Washington State and Oregon DOTs; Above photo courtesy of Wikimedia Commons.

“However, they also [hang out] under bridges that span ephemeral waterways, especially those near irrigated agricultural fields,” he added. “Most bat species are not protected by federal or state law, but the New Mexico DOT recognizes their importance in the ecosystem and the benefits they provide to the agricultural industry.” 

In addition, he said, New Mexico DOT “would rather manage bats with flexibility and adaptability, rather than by strict protocols and measures. It is in New Mexico DOT’s best interest to avoid listing of a bat species under the Endangered Species Act.”

Generally, Hirsch explained that the New Mexico DOT will install bat boxes under new bridges if the previous bridge supported daytime bat roosting activity. His agency will also perform bat exclusion measures if a bridge is scheduled for demolition or major rehabilitation during the “active season” for bat colonies.

“The active bat season usually coincides with the migratory bird nesting season in northern New Mexico,” he noted. “Therefore, avoidance and exclusion efforts usually protect both migratory birds and bats.”

A recent challenge faced by the agency is the cost of undertaking bat exclusion measure, as funds for such measures usually come from the limited resources of the New Mexico DOT’s environmental bureau budget. To change that, he said the department is evaluating cost effective partnerships with universities as well as with other state and federal agencies.

Research by the Texas DOT is creating a clearer picture of what specific types of bridge and culvert structures best buoy bat populations. The agency surveyed hundreds of bridges and culverts in West Texas over the last two years and found that state highway type pre-stressed concrete girder bridge designs situated near evergreen forests, deciduous forests, and standing water had a positive correlation to bat presence. Texas DOT also found that interstate highway and square box girder variables had a negative correlation on bat presence. 

“These results corroborate and refine anecdotal observations from decades of Texas DOT work to attract and maintain healthy bat populations on bridges, including the placement of artificial roosts on bridges that are not the right type, but are in the right ecological setting,” noted Dr. Stirling Robertson, the biology team lead in Texas DOT’s natural resources management section.

He added that those variables differed between species of bats, which is allowing Texas DOT to target species-specific bridge design solutions.

With a better understanding of the variables attracting bats to bridges and culverts, as well as the demonstrable success of artificial roost design and placement, Texas DOT is looking for future success by applying this knowledge where appropriate across the state.

“Bridges that are in the appropriate ecological setting and that are being replaced or rehabilitated give us ideal opportunities to enhance or preserve bat colonies,” Robertson pointed out. “We can also retrofit existing structures with artificial roosts if the existing design is not bat friendly.”

EPA Issues Clean Water Act Section 401 Final Rule

The Environmental Protection Agency issued a final rule on June 1 that it said increases the transparency and efficiency of the Clean Water Act Section 401 certification process in order to promote the timely review of infrastructure projects.

“EPA is returning the Clean Water Act certification process under Section 401 to its original purpose, which is to review potential impacts that discharges from federally permitted projects may have on water resources, not to indefinitely delay or block critically important infrastructure,” explained EPA Administrator Andrew Wheeler in a statement.

He noted that EPA finalized this rule pursuant to the President’s Executive Order 13868 to help spur construction of important energy infrastructure projects. 

The EPA said this final rule overhauls the text, structure, and legislative history of Section 401 for the first time in 50 years in several areas:

  • It specifies statutory and regulatory timelines for review and action on a Section 401 certification—requiring final action to be taken within one year of receiving a certification request.
  • It clarifies the scope of Section 401, including clarifying that 401 certification is triggered based on the potential for a project to result in a discharge from a point source into a water of the United States. When states look at issues other than the impact on water quality, they go beyond the scope of the Clean Water Act.
  • It reaffirms the agency’s statutory responsibility to provide technical assistance to any party involved in a Section 401 water quality certification process.
  • It promotes early engagement and coordination among project proponents, certifying authorities, plus federal licensing and permitting agencies.

Sen. John Barrasso, R-Wyo., chairman of the Senate Committee on Environment and Public Works, endorsed the EPA’s move in a June 2 statement as a way to allow important energy infrastructure projects to “get done faster.”

By contrast, Rep. Peter DeFazio, D-Ore., chairman of the House of Representatives Committee on Transportation and Infrastructure, noted in a statement on June 5 that removing environmental review processes “will not be the magic cure to our nation’s economic downturn” due to the COVID-19 pandemic.

Environmental News Highlights – June 10, 2020

A roundup of headlines curated for state transportation environmental professionals


House T&I Releases Five-Year $494B Surface Transportation Bill – AASHTO Journal

AASHTO’s Statement on House Surface Transportation Bill – AASHTO Journal

Proposed Rule: Increasing Consistency in Considering Benefits and Costs in the Clean Air Act Rulemaking Process – EPA (Announcement)

Trump seeks to scale back environmental reviews for projects – Associated Press (see Federal Register Notices below)

Gateway Tunnel opposed by Trump could get funding from new House bill – NJ.com

Conservation bill clears one Senate hurdle, but more remain – Roll Call


Transportation Industry Asks President to Support COVID-19 Funding Relief for State DOTs – AASHTO Journal

RTD taps national medical researcher for insights on recovering from COVID-19 – Regional Transportation District (Press release)

How COVID-19 could speed up smart-city visions – Deutsche Welle

The pandemic response slashed traffic; what did it teach us about transportation planning? – Wisconsin State Journal


What Trump’s permit order means for NEPA, energy and race – E&E News

Outdated NEPA needs modernizing. Just ask Warren Buffett – Utility Dive (Opinion)


Michigan DOT Assesses Needs, Starts Repairs After Extensive Flooding – Transport Topics

North Texas Innovation Alliance Consortium Launches to Create the Most Connected, Smart and Resilient Region in the Country – North Texas Innovation Alliance (Press release)

Environment Report: Climate Plans Across the Region Are Hitting Roadblocks – Voice of San Diego

U.S. Water Infrastructure Has One Dam Big Problem – Triple Pundit

Siting Board Approves Its Largest Wind Farm to Date – New York State Board on Electric Generation Siting and the Environment (Press release)

With Fewer People in the Way, Transportation Projects Speed Ahead – New York Times (subscription)

Issues Of The Environment: Prioritizing Urban Planning In Combatting Impacts Of Climate Change – WEMU

Environmental Protection and Infrastructure Investments Are Necessities, Not Luxuries – Earth Institute/Columbia University (Opinion)


Carbon Neutral vs Carbon Negative: What’s the Difference? – Business News Wales


EPW Hearing: Infrastructure Vital to Economic Recovery, Social Equity – AASHTO Journal

Why communities fighting for fair policing also demand environmental justice – Los Angeles Times (subscription)


Planners who want to restore East Bay marshland seek public input – East Bay Times

Australia’s Water Is Vanishing – Bloomberg


Amid Protest and Pandemic, Urban Parks Show Their Worth – CityLab


Trails for two-wheelers: A look at the United States Bicycle Route System – MultiBriefs

Michigan moves to overhaul its waste industry to favor recycling over landfills – Lansing State Journal

Cities criticized for shutting down bikeshare amid protests, pandemic – CNN

Rails-to-Trails Conservancy: “INVEST in America Act” Goes Far To Deliver the Transportation Infrastructure America Needs – Rails-to-Trails Conservancy (Press release)

House draft transportation bill contains $6.3B for biking and walking infrastructure – Bicycle Retailer


“Tell Us ‘Our’ Story”: “What is your vision for the Transportation Research Board 100 years from now?” – TRB

TRB 2021 Annual Meeting: Paper submissions due August 1 – TRB (Announcement)

RFP: Emergency Response: Organizational and Operational Models Used by State DOTs – TRB (RFP availability)

TR News: Implications of the California Wildfires for Health, Communities, and Preparedness TRB (Publication Announcement)

Asset Management Approaches to Identifying and Evaluating Assets Damaged Due to Emergency Events – NCHRP (Publication Announcement)


EO on Accelerating the Nation’s Economic Recovery from the COVID-19 Emergency by Expediting Infrastructure Investments and Other Activities – White House (Executive Order)

Bighorn National Forest; Wyoming; Invasive and Other Select Plant Management – Forest Service (Notice of intent to prepare an environmental impact statement)

Forest Service Manual 2750; Special Uses Management Manual; Leasing Forest Service Administrative Sites – Forest Service (Notice of availability)