AASHTO Asset Management Task Force s7

NCHRP 20-7 Proposed Research Needs Statement AASHTO Technical Committee on Hydrology and Hydraulics Karuna Pujara March 25th, 2015

TITLE State of Practice on Use of Highway Embankments as Levees

BACKGROUND / NEEDS STATEMENT

The Federal Emergency Management Agency (FEMA), primarily through the National Flood Insurance Program (NFIP), works with communities to determine floodplain areas threatened by flood damages and sets appropriate insurance rates for property owners within those areas. The primary means to determine the locations of these flood prone areas are through flood insurance studies (FIS) and associated flood insurance rate maps. By the time the FEMA and the communities began conducting these FIS, much of our Nation’s highway system had already been constructed, including embankments within some floodplains.

Recent FEMA map modernization and levee certification initiatives have revealed that for many years some highway embankments may have been either inadvertently or incorrectly designated as levees or other flood control structures. Also, some NFIP communities incorrectly assumed that these embankments provided some level of protection. Until recently, the Federal Highway Administration (FHWA) and many State Departments of Transportation (DOTs) were unaware of such assumptions.

Furthermore, there have been recent instances where the FEMA, other floodplain regulators, and communities (hereafter referred to as ‘entities’) have approached DOTs to request DOT certification of these highway embankments as levees or flood control structures. Some entities have suggested that DOTs need to retrofit these embankments into levees and do so using Federal-aid highway funds, thus allowing for certification. Many times these entities cite significant economic hardship for the community should the DOT not take such actions (FHWA 2008).

RESEARCH OBJECTIVE The primary objective of this research is to provide State DOTs and other hydraulic and geotechnical practitioners the state of practice on use of highway embankments as levees.

WORK TASKS Tasks anticipated in this project include the following:  Identify pertinent engineering documents from various agencies (e.g. FHWA, USACE, FEMA, etc) that may assist State DOTs in evaluating the different levels of risk associated with highway embankments located near rivers and waterbodies.  Collect information from State DOTs regarding current statutes that address financial liability (e.g. joint and several liability).  Provide a report summarizing the information collected which will provide the state of the practice on use of highway embankments for levees. URGENCY Throughout the nation, many FIS are out of date and are being re-studied. In many locations, highway embankments may have been either inadvertently or incorrectly designated as levees or other flood control structures in the original FIS. In addition, the proposed revised Executive Order 11988 is potentially increasing the design elevation for levees. Certification of a levee requires a thorough engineering evaluation, which can have a significant associated cost. This synthesis will assist in providing State DOTs a proactive position for evaluating risks and financial liability associated with highway embankments located near rivers and waterbodies.

FUNDING REQUESTED AND TIME REQUIRED It is estimated that this research will take 6 months to complete and will require $40,000.

CONTACT PERSON Casey Kramer – Washington State Department of Transportation 310 Maple Park Ave SE PO Box 47329 Olympia, WA 98504-7329 360-705-7262 [email protected]

Joe Krolak – Federal Highway Administration 202-366-4611 [email protected]