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Regional Ecosystem Framework


The Regional Ecosystem Framework, or REF, is a tool that identifies areas of relative ecological importance in the Dallas-Fort Worth region. Transportation partners and local governments that are developing infrastructure projects can use the REF as a preliminary screening tool to identify environmental impacts their projects may have and identify mitigation areas to offset any impacts.

The development of the REF was a collaborative effort between the Transportation and Environment & Development departments at the North Central Texas Council of Governments (NCTCOG) with assistance from resource and regulatory agencies. The tool is based on the Federal Highway Administration's vision to integrate economic, environmental, and social needs during infrastructure development as described in "Eco-Logical: An Ecosystem Approach to Developing Infrastructure Projects."

The REF uses a watershed approach to define areas of ecological importance because ecosystems do not follow city, county or other political boundaries. The tool evaluates ecological priorities at the subwatershed level using Geographic Information Systems (GIS) and designates scores based on:

  • Green Infrastructure, including the presence of natural lands, agricultural lands, and wildlife habitat;
  • Ecosystem Value, including the rarity and diversity of plants and animals and the sustainability of the ecosystem compared to the entire ecoregion; and
  • Water Considerations, including the presence of impaired water segments, flood zones, and wetlands; and the quantity of surface water in the subwatershed.

Most REF layers score subwatersheds based on their ecological value relative to other subwatersheds in the Dallas-Fort Worth region. However, three REF layers score subwatersheds based on their ecological value relative to their entire ecoregion, which includes land beyond the Dallas-Fort Worth region. This occurs because the data used for the Diversity, Ecosystem Sustainability, and Rarity layers were developed for the Regional Ecological Assessment Protocol (REAP) produced by EPA Region 6, which covers the South Central United States. For example, subwatersheds in the western counties are located in the Cross Timbers and Prairies ecoregion, so they are compared to the area in Oklahoma that also falls within the Cross Timbers and Prairies.

Mapping Function

NCTCOG created the Regional Ecosystem Framework Interactive Viewer to share the REF layers and other pertinent environmental layers with transportation and resource agency partners. The interactive tool allows users to overlay REF ecological data with additional spatial data relevant to efforts to conserve natural areas or mitigate the environmental impacts of infrastructure projects.

Launch Interactive Mapping Tool

Data Dictionary

The data dictionary contains descriptions of each of the layers as well as links to the agency or non-governmental organization that produced the data. Governments and planners who are developing infrastructure projects should consult with these and other resource agencies during the planning process.

View Data Dictionary

User Guide

The User Guide gives illustrated descriptions of all the functions available in the Interactive Mapping Viewer. The REF Interactive Viewer is built on Esriís ArcGIS Online platform and is intended to be a simple-to-use yet in-depth tool. The primary operations are similar to the commonly used Google Maps or Bing Maps. The User Guide and Data Dictionary are also accessible from within the application.

Interactive Viewer User Guide

REF Advanced User Guide (To add layers to the map or access REF data in ArcMap Desktop)

Wetland and Stream Mitigation Assessment


The Mitigation Assessment analyzed the supply of mitigation credits and estimated the demand that will be created by roadway projects included in the North Central Texas region by accessing credit ledger data from the Regulatory In-Lieu Fee and Bank Information Tracking System. Models were generated in Geographic Information Systems to identify and prioritize potential wetland restoration, wetland enhancement, and stream enhancement mitigation sites.

Mitigation Assessment Report  



Sustainability in the Denton Greenbelt Postcard


NCTCOG has received a grant from the Federal Highway Administration to integrate sustainability best practices into transportation planning. A completed feasibility study will be analyzed using the web-based Infrastructure Voluntary Evaluation Sustainability Tool (INVEST). This analysis will identify best practices that can be applied to a study on the Denton County Outer Loop/Greenbelt Parkway, which is expected to pass through a park that provides recreation trails and wildlife habitat.


Investing in Sustainability Fact Sheet

Regional Outer Loop Feasibility Study Report – November 2011
(Historical study provided for reference only)

Executive Summary 
Volume 1 (Report) 
Volume 2 (Maps) 
Volume 3 (Transportation Data)  
Volume 4 (Public and Agency Involvement) 
Part A (Meeting Information - 2007) 
Part B (Meeting Information - January to April 2008) 
Part C (Meeting Information - May to June 2008) 
Part D (Meeting Information - July to December 2008)
Part E (Meeting Information - January to April 2009) 
Part F (Meeting Information - May to December 2009)
Part G (Meeting Information - January 2010 to November 2011 & Website) 

Meeting Information

TRACES Meeting
June 17, 2015
North Central Texas Council of Governments


Implementing Eco-Logical Stakeholder Meeting
June 4, 2014
North Central Texas Council of Governments

Agenda  |  Presentation  |  Meeting Notes

Project Reports

Project Maps

Regional Ecosystem Framework Update and Identification of Regional Focus Areas - Fall 2014

Loop 9 Conservation Vision and Opportunities - January 2015

Regional Ecosystem Framework Final Report - Completed June 2011

Additional Resources

Federal Highway Administration Eco-Logical

Mobility 2040

NCTCOG Planning and Environmental Linkages


Send us your comments or questions about the interactive tool, REF, or data.

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Kate Zielke
Transportation Planner III

Tamara Cook
Manager of Environmental Programs

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