Synthesis and Study of the Roadside Vegetation Establishment Process

The Texas Pollutant Discharge Elimination System (TPDES), which is administered and enforced by the Texas Commission on Environmental Quality (TCEQ), requires perennial vegetation to 70 percent of native or adjacent background vegetation before a Notice of Termination (NOT) can be filed. The Texas Department of Transportation's (TxDOT) roadway projects often terminate at times of the year when establishing permanent vegetation is very difficult or nearly impossible. Even when the construction calendar and the ideal growing season line up, establishing vegetation is still a constant challenge. Regions of the state that have limited rainfall and a shorter growing season often take multiple years to establish vegetation to meet the TPDES requirements. The objective of this study was to provide a more diverse set of tools and options for TxDOT personnel that will help ensure timely vegetation establishment to meet the TPDES regulatory requirements, minimize project delays, and help reduce long-term costs in vegetation development and management. To achieve these objectives, the researchers: (1) compared TxDOT's practices compare to those of other state departments of transportation (DOTs) and related fields, (2) identified methods for more rapid vegetation establishment for meeting the TPDES requirements using field demonstration plots seeded according to current TxDOT practices, (3) devised a tool to assist design personnel not familiar with the vegetation establishment process, and (4) developed a vegetation establishment field guidebook.