NWF's David Muth talks of southeast LA marsh restoration
On Wednesday, 7/26/17, David Muth, director of the National Wildlife Federation's Gulf Restoration Program, presented his program entitled "The Once and Future Delta" to a gathering of naturalists at Loyola University in New Orleans. As pretty much everyone in the United States knows, Louisiana is losing land at an alarming rate, and now the state finally has some money to do something about it, thanks in part (in a bittersweet way) to the BP oil spill back in 2010.
According to Mr. Muth, the state has about $7 billion to spend right now from the settlement, and officials are debating how best to use that money, with the results of the discussion available for public review at the 2017 Coastal Master Plan website.
http://coastal.la.gov/2017-coastal-master-plan/
The state's Coastal Master Plan, initially presented in 2007 and required to be reviewed every five years, calls for spending $50 billion over the next 50 years, creating 800 square miles of land by funding 124 projects.
That's not much land, and a whole lotta money.
In Mr. Muth's opinion, the state cannot rely solely on building marshland through pumped-in sand, but must also open up multiple Mississippi River sediment diversions that would use the immense flow to lay down sand and silt and clays. Ongoing right now is public comment into one phase of the the Mid-Barataria sediment diversion, a one-of-a-kind $1.3 billion project that needs multiple permits from a host of agencies. The proposed project is located near Myrtle Grove on the West Bank of Plaquemines Parish.
Mr. Muth is very optimistic about the land-building potential of this project, as new science has recorded river sand deposits in that area that surpass usual levels. Should the project be approved, opening up a sediment diversion at Myrtle Grove should be most productive for the Barataria basin, he said, due to this factor; and also because the location is inland and buffered by intact marsh. It will build land more efficiently than existing freshwater diversion locations that open into the Gulf or deep bays, he said.
Of course, what he didn't say and what we all know is the political opposition, backed by resident opposition. Many people's families and jobs are at stake, but the truth is, all the fisheries and related industries are vanishing anyway. Mr. Muth talked about the Shifting Baseline Syndrome, a term coined by a biologist in the 1990s to describe information loss that rides the waves of generations. For example, history tells us that when the Europeans first arrived in the Louisiana delta region, bison roamed the marshes, which apparently were much firmer than they are today. Few would know this; Mr. Muth, a historian by formal training, has researched published anecdotal reports of European observers who were on the scene of initial exploration. Reports from that time include sightings of wildlife far surpassing the meager numbers and quality (as in size and thus longevity) that we see today.
According to Mr. Muth, levees have been part of the Louisiana landscape from the very beginning of European settlement. In order to obtain a land grant, settlers along the river agreed with the royal crown back home to build levees protecting their property from floodwaters and thereby making it suitable for cultivation. By 1803, levees lined the river from Baton Rouge to New Orleans. Poorly built and sloppily maintained, the levees often broke, creating crevasses; one particular event, known as Sauve's Crevasse in 1849 and occurring in a now-suburban community known as River Ridge just upriver from New Orleans, flooded the city (including the lower parts of the French Quarter) and is known as the last time New Orleans was inundated by floodwaters originating from the river. That is the crux of the problem, this lack of floodwaters from river, as New Orleans and the land surrounding it is strictly deltaic in origin, with the Earth's crust buried beneath 30,000 feet of river-borne sediment; the boundary between the recent delta and the older coastline is the Northshore of Lake Pontchartrain.
For those who don't live around here and may not be aware, the land in South Louisiana was built by the river's sediment deposits as it changed course six times over the past 4,600 years.
Other river diversions mentioned by Mr. Muth include Caernarvon and Davis Pond, both of which are freshwater diversions (not sediment diversions) intended to reduce salinity levels and thus make the marsh more habitable to all things wild. One think tank's radical idea worth mentioning, he said, includes a plan to eliminate the river levees south of New Orleans, allowing the land to rebuild, and he points to the Atchafalaya Basin as proof-positive as to potential land-building opportunities there.
Any way one looks at it, cutting-edge science is going on in Louisiana right now, prompted by an unprecedented Holocene event in this part of the world. As Mr. Muth said, "We're watching whole landscapes wash away -- a rare sight."
