Recommended Techniques and Best Practices to Reduce, Minimize or Mitigate Transportation Impacts on Watershed Functions and Values

Focus Area

Water Quality/Wetlands


Natural Resources






2-3 years

Research Idea Scope

TERI Administrator Note: Selected for FY12 NCHRP funding as NCHRP 25-37

This problem statement was identified by the Natural Systems and Ecological Communities Subcommittee of AASHTO’s Standing Committee of the Environment (SCOE) during the 2010 research prioritization process. The goal of this research problem statement is to assist Departments of Transportation to better avoid, minimize, and mitigate infrastructure impacts on watersheds.  The result of this research will be the development of a decision making framework for state departments of transportation (DOTs) to reduce transportation impacts on watersheds. 
Over the last few years DOTs and their partners have been emphasizing the watershed approach.  A watershed approach is a method for sustaining or restoring watersheds and their functions and values. It is based on a collaboratively developed vision of desired future conditions that integrates watershed, economic, and social factors. It is applied within a geographic framework defined primarily by watershed boundaries.  A watershed approach will help move agencies from project boundaries to a wider regional context. 
This project would build off of NCHRP Project 20-68A, the U.S. Domestic Scan Program: Scan Repoort 08-03 Best Practices in Addressing NPDE and Other Water Quality Issues in Highway System Management.  The Domestic Scan report identifies research gaps and recommendations for national discussions. This research project should place an emphasis on source control for pollutants of concern that are ultimately named in many statewide Total Maximum Daily Loads (TMDLs) as emanating from transportation systems.  The Domestic Scan noted that research on source control was an immediate need for the DOTs.  The final project report can be found at
This approach will allow a more efficient and cost effective manner to avoid and minimize impacts to our nation’s water bodies.  The Domestic Scan report indicates that source control research would be the “most effective and least costly approach to surface water improvement.”  This project will enable DOTs to work collaboratively with resource agencies and comply with current and future regulations.   
Online search of TRB’s TRIS and RIP databases only found one related research project.
Minimizing Water Quality Impacts of Road Construction Projects North Carolina State University, Raleigh; North Carolina Department of Transportation; Federal Highway Administration, 2007.  The purpose of this study was to determine the potential impacts of sediment from a large construction project on nearby streams, and to evaluate approaches to reduce those impacts.
Unlike the proposed research statement this project only looked at the impacts of the construction process on nearby streams.  The proposed research’s intent is to develop a decision making framework.  The proposed project suggests using a holistic watershed approach to look at transportation construction, operations and maintenance.  Additionally the completed research only recommends minimization techniques.  Although research has been completed in this area it only scratches the surface of the intended project.  It is suggested that the researcher review the results of the completed watershed-based research prior to undertaking this task.     
The objective of this research would be the development of a decision making framework for state departments of transportation (DOTs) to reduce transportation impacts on watersheds.   Below is a general description of the scope of work that could be used to inform the development of a web-based decision making tool/template.  
            General Scope of Work:
Task 1: Through a desk scan collect the methods/strategies that state departments of transportation (DOTs) are utilizing to determine impacts to aquatic resources and water quality and how the DOTs make decisions to avoid, minimize or mitigate transportation impacts on watersheds.  Also collect the requirements of each DOTs NPDES, 401 Certification, MS4 and settlement requirements.  The collection of requirements will facilitate the researchers in teasing out what techniques are applicable under certain requirements and meet the goal of watershed protection.    
Task 2:  Complete a literature review to collect unique methods that private industry and large developers are using to reduce and mitigate for impacts.  Review and synthesize the strategies that are applicable to DOTs.
Task 3: Once the methods are collected from the DOTs, survey the states to collect performance data related to the decision making processes.
Task 4: Based on the highly rated processes develop a decision making framework for DOTs to utilize to avoid, minimize or mitigate impacts.  Provide a methodology for the framework..  One dimension of the framework would be related to the information collection in task 1.  The research team should group the technologies/techniques by innovations that meet the permit requirements.
Task 5: For impacts that require minimization or mitigating collect best management practices (BMPs) and recommended techniques from the DOTs.
Task 6: Complete a cost/benefit analysis on the BMPs.  Collect performance data from DOTs that are utilizing the BMPs.  When necessary/appropriate test the BMPs in the field.
Task 7: Complete the decision making framework by recommending BMPs and recommended techniques to complete the decision making framework..  The decision making tool should be a userfriendly web-based tool/template. 
Task 8: Test the frame work on urban, rural, suburban and multiple types of watersheds (watersheds can either be a standard size (i.e. acreage) or a wide variety of sizes.).  Revise the framework based on input from the practitioners.
Task 9: Educate practitioners on how to use the framework through a series of workshops and/or webinars. 
Task 10:  Publish the final report and provide a list of recommended future studies or recommended research needed to further advance DOTs towards a watershed/ecoregional approach which will better enable them to reduce impacts.

Urgency and Payoff

The current legislative and regulatory climate has places a spotlight on watershed protection and pollutant reduction.  Transportation construction, operations and maintenance contributes to the degradation of our nation’s watersheds.  This research statement will enable DOTs to better comply with pending legislation and regulations.  This research will assist the DOTs in demonstrating to congress, the administration and the general public that transportation is doing their part in protecting our water resources and that DOTs are doing their part in leaving the natural environment in a better condition than it was before the infrastructure development.   
In the current economic crisis, DOTs and their partners are looking for ways to streamline processes and utilize resources in a cost efficient manner.  The cost benefit portion of this research statement will ensure that DOTs are able to use their resources in the most appropriate manner.  DOTs have a variety of best management practice (BMPs) available for use.  The BMPs differ in cost and effectiveness.  This portion of the project will also demonstrate to resource agencies that many costly BMPs and techniques do not have a vast impact on watershed protection and/or improvement. 

Suggested By

Jy S. Wu, University of North Carolina at Charlotte; Frannie Brindle, Chair, AASHTO SCOE/Subcommittee on Natural Systems and Ecological Communities Oregon Department of Transportation

[email protected]