Louisiana Oil Spill Coordinator's Office  
Louisiana.gov > DPS > LOSCO > Natural Resource Damage Assessment (NRDA) Text Size plus button minus button
gear icon Download Adobe Reader

Some documents on this page are in PDF format. Click here to download the free Adobe Reader.

Get Adobe Reader

Natural Resource Damage Assessment (NRDA)

When oil spills injure natural resources such as waterways, vegetation, or wildlife, the Louisiana Oil Spill Coordinator’s Office (LOSCO) and its trustee partners seek compensation for the public from the Responsible Party. To guide our efforts, we use a process called a Natural Resources Damage Assessment (NRDA).

The Oil Pollution Act of 1990 (OPA), 33 USC 2701 et seq. and the Louisiana Oil Spill Prevention and Response Act of 1991 (OSPRA), La. Rev. Stat. 30:2451 et seq., are the principal federal and state statutes, respectively, authorizing federal and state agencies and tribal officials to act as natural resource trustees for the recovery of damages for injuries to natural resources and services resulting from incidents in Louisiana.

NRDA Trustees

On the state level, the trustees include:

The federally designated natural resource trustees include:

The NRDA process provides the framework for determining:

  • The resources that have been injured
  • The loss to the public
  • How the resources can be restored
  • The type and amount of restoration that is appropriate

Both federal and state NRDA regulations provide a step-by-step process for trustees to determine injuries, to assess damages, and to develop and implement restoration projects that compensate the public for injuries to natural resources impacted by an incident. In general, the NRDA process involves three steps: (1) preassessment; (2) restoration planning; and (3) restoration implementation.

NRDA Process

Step One: Preassessment

LOSCO and its trustee partners evaluate the extent of the injury to natural resources. We determine whether the oil spill cleanup will eliminate the threat of ongoing injury. If injuries are expected to continue, and feasible restoration alternatives exist to address such injuries, we move to Step Two: Restoration Planning. The notice to conduct Restoration Planning is published in the Louisiana State Register.

Step Two: Restoration Planning

In this phase, LOSCO and its trustee partners evaluate potential injuries to determine the appropriate scale of restoration activities.  First we conduct an injury assessment, which determines the nature and extent of injuries to natural resources and services.  Next we select restoration options from a range of alternatives.  Whenever possible, we choose alternatives that will return the injured resources and services to their pre-spill conditions.  We also seek to compensate the public for losses incurred.  The Responsible Party is liable for paying the cost of restoration plus reasonable assessment costs.

Step Three: Restoration Implementation

LOSCO works with its trustee partners and the Responsible Party to design and implement restoration actions.  We invite the public to comment on the restoration plans before they are implemented.  All restoration plans include monitoring provisions to allow for corrections, measure progress, and determine the restoration effort’s overall success.  In many cases, the Responsible Party assumes responsibility for implementing the restoration plan, with oversight from LOSCO and its trustee partners.

To assist the natural resource trustees in carrying out their NRDA responsibilities under OPA and OSPRA, State of Louisiana and federal natural resource trustees have developed a jointly administered statewide Louisiana Regional Restoration Planning Program (RRP Program)

NRDA Incidents Status & Administrative Record

No two NRDA cases are alike, and the process may take years to complete. But, as the cases below indicate, successfully completed NRDA cases deliver real benefits to the citizens of Louisiana.

Location Parish Date of Incident Amount (bbls) Type of Incident Type of Habitat/ Resource Injured Preferred Alternative Restoration Project
Deepwater Horizon Multiple 04/20/10 Unknown Well Blowout All Coastal Habitats/Resources Marsh Creation 104 Acres of Brackish Marsh
Oyster Cultch & Hatchery 805 acres of oyster cultch plus hatchery
To Be Determined To Be Determined
Breton Island Plaquemines 06/12/05 ~15 Tank Overflow Birds To Be Determined To Be Determined
West Champagne Bay Jefferson 04/19/05 ~600+ Pipeline Rupture Salt Marsh To Be Determined To Be Determined
Raphael Pass Plaquemines 09/21/04 500 Tank Failure Brackish Marsh To Be Determined To Be Determined
Mendicant Island Jefferson 12/02/03 ~400 Pipeline Rupture Salt Marsh To Be Determined To Be Determined
Lake Washington Plaquemines 03/02/03 995 Pipeline Rupture Salt Marsh To Be Determined To Be Determined
Terrebonne Bay Terrebonne 01/30/03 160 Pipeline Rupture Salt Marsh To Be Determined To Be Determined
Duck Lake St. Martin 12/04/02 1,000 Pipeline Rupture Cypress Tupelo Swamp Vegetative Planting/ Invasives Control 8.61 Acres of Cypress-Tupelo Swamp
North Pass Plaquemines 09/23/02 Unknown Storage Tank Rupture Brackish Marsh Crevasse Splay 6.43 Acres of Marsh
East Lake Palourde Assumption Unknown Unknown Pipeline Rupture Cypress Tupelo Swamp Vegetative Planting/ Invasives Control 13.3 Acres of Cypress-Tupelo Swamp
Little Lake Lafourche 04/06/02 ~1800 Pipeline Rupture Intermediate Marsh Marsh Creation To Be Determined
Mosquito Bay St. Mary 04/05/01 1,000 Pipeline Rupture Salt Marsh Marsh Creation To Be Determined
Mississippi River Plaquemines 11/28/00 13,500 Vessel Grounding River Bank & Levee Crevasse Splay 4.7 Acres of Marsh
Public Use Enhancement Construct Public Dock & Picnic Area
Four Bayou Pass Plaquemines & Jefferson 11/24/99 850 Pipeline Rupture Water Column & Barrier Islands Acquisition & Enhancement 2.8 Acres of Chenier Oak-Hackberry Habitat
Lake Grande Ecaille Plaquemines 09/22/98 500 - 1,500 Well Blowout Brackish Marsh Marsh Creation To Be Determined
Cravens Vernon 08/08/97 13,000 - 19,000 Well Blowout Forest RCW Habitat Enhancement 300 Acres RCW Habitat Enhancement
Freshwater City Vermillion 06/21/97 2,000 Pipeline Rupture Salt Marsh Vegetative Planting 4 Acres of California Bulrush
Vegetative Planting 2 Acres of California Bulrush
Lake Barre Terrebonne 05/16/97 6,561 Pipeline Rupture Salt Marsh Vegetative Planting 18.6 Acres of Marsh
Attakapas St. Mary 11/26/96 4,762 Well Blowout Wetlands Vegetative Planting 30 Acres Forested Wetlands
Blind River St. James 05/24/96 11,308 Pipeline Rupture Wetlands Preservation/ Enhancement 33 Acres Forested Wetlands
Public Use Enhancement Public Parking Area & Wharf Enhancements
Protection of Coastal Forested Wetlands Addition to Educational Center
Dixon Bay Plaquemines 01/12/95 250 - 2,500 Well Blowout Brackish Marsh Crevasse Splay 5 Acres Marsh
Paradis St. Charles 01/15/93 ~800 Leak in SWD System Fresh Marsh/ Flotant Raking of Biological Litter 1.6 Acres Primary Restoration
Timbalier Bay Lafourche & Terrebonne 09/29/92 2,285 Well Blowout Salt Marsh Marsh Creation 21.7 Acres Marsh
Lake Salvador St. Charles 02/04/91 55 Well Open Water Shoreline Protection 85 Feet Breakwater Pilings

Related Links

NOAA Damage Assessment and Restoration Program

NRDA Preliminary Assessment Worksheet

USDOI NRDA and Restoration Program

USDOI Office of Environmental Policy and Compliance

NRDA Restoration Project Submittal Form

back to top