Swamp 2 A tupelo swamp in the Nature Conservancy’s Caddo Black Bayou Reserve.

This past week our BIOL 560 class had the opportunity to learn about mitigation banking from Ms. Nelwyn McInnis, the Mitigation Program Manager at the Nature Conservancy.  The Nature Conservancy is an international nonprofit  land-based conservation organization that is dedicated to “protecting the lands and waters on which all life depends” (The Nature Conservancy’s mission statement).  Ms. McInnis has worked with the Nature Conservancy for over 20 years and has been the project leader for the conservancy’s Southeast Louisiana Pine Flatwood Wetland Mitigation Bank since 1998.

Ms. McInnis explained to us the legislation behind wetland conservation that led to mitigation banking.  In short, several federal acts and guidance documents written in the past several decades have influenced the development of mitigation banking, but the most important one was the 2008 rule added under section 404 of the Clean Water Act.  The Clean Water Act gives our government jurisdiction to regulate all “navigable waters”.  Wetlands adjacent to navigable waters or connected to them by a “significant nexus” fall under this jurisdiction too.  The 2008 rule added the goal of “no net loss” of wetlands, which is where mitigation comes in.

So if a developer wants to build in an area with wetlands, they have to make sure their project won’t cause any net loss to those wetlands.  The easiest thing for the developer to do would be to avoid harming the wetlands altogether, but when that’s not entirely possible, they should still plan their project to minimize the level of impact they cause to the wetlands.  If the developer finds that there is no way around the fact that their project is going to cause the loss of some of those wetlands, the developer has to make up for that loss by adding to wetlands somewhere else.  Not only that, but whenever possible, the replacement wetland has to be located in the same watershed as the destroyed wetland and it must be the same type of wetland.

This is the essential idea behind mitigation, but how do you go about adding wetlands?  There are actually four mitigation methods for doing this: restoration, establishment, enhancement, and preservation.  Restoration involves converting land that was once converted from being a wetland back to its previous wetland state.  This technique adds overall wetland acreage and function to the ecosystem.  Establishment also adds wetland acreage and function, but involves converting land that previously was not a wetland into a wetland.  Enhancement involves improving an existing wetland to increase its ecosystem function.  Enhancement only adds function, not acreage, so in mitigation projects that do wetland enhancements, companies often have to enhance several acres of wetland for every one acre of wetland they destroy.  Preservation involves taking a wetland that already exists and maintaining it exactly the way it is, to preserve acreage and function, but this process doesn’t add to either one, so like in the case of enhancement projects, mitigators would have to preserve several acres to make up for every one acre of wetland they destroy.

This sounds complicated, right?  Mitigation can get quite complicated, and most people don’t want to deal with that extra bit of headache.  It’s much easier to let a third party take care of all that mitigation project management so you can just write a check and be done with it.  So that’s where mitigation banks come in!  Mitigation banks do exactly that: they buy land and manage different wetland mitigation projects, which translate into credits, which can then be sold to developers who need however many credits of wetlands mitigated.

sunset-at-abita-creek-flatwoodA pine savanna from the Nature Conservancy’s Abita Creek Flatwoods Preserve.

This is the job of the Nature Conservancy!  Or rather, one of the jobs, since the Conservancy is actually a very large organization involved in many different kinds of conservation projects around the world.  The southeast Louisiana field office where Ms. McInnis works has become somewhat specialized in the conservation of pine savannas, a very unique wetland type made up of pine trees, grasses, and an assortment of carnivorous plants.  They manage several wetland conservation projects across southeast Louisiana and Mississippi, not all of which are pine savanna wetlands.  The Nature Conservancy gets credits for the acres of wetlands they create or restore and the value of functions their wetlands provide.  Then the conservancy sells these credits to developers and companies that need credits to make up for the wetlands they harmed.

TNC_conservation_sitesMap of the Nature Conservancy’s conservation sites in southern Louisiana and Mississippi.

And there you have mitigation banking!  A complicated yet clever process that fulfills two needs in one swoop.  Conservationists that need funding for their management projects and developers who need wetlands to be conserved on their behalf can work together to solve their problems with mitigation banking.  It’s good for business and it’s good for wetlands!

By Kristen Chatelain

Photos from the Nature Conservancy website: