“Saving the Basin” – What does it mean?

I have often said that everyone that i meet around the Atchafalaya has the same goal; they all want to “Save the Basin.” The problem is that they all have a different idea of what that phrase means.

During the past week, stories have appeared on television news and in the local newspapers concerning the future of another basin in south Louisiana. It is the Alligator Bayou/Spanish Lake basin at the borders of Ascension, Iberville and East Baton Rouge Parishes, physically not far from the Country Club of Louisiana, but far away in attitude. I was awakened to the recent issues by an email message that was circulated by several environmental groups in the area, calling for an email barrage on Iberville Parish President Mitch Ourso for calling for the opening of the floodgate at the mouth of Alligator Bayou, where it would naturally spill into Bayou Manchac. I live on Bayou Manchac so i have been involved in discussions about the management of the floodgate in the past. I also served on a task force led by the Corps of Engineers after a particularly big flood in 2001.

In bygone days, the Spanish Lake basin, along with other low-lying areas over in East Baton Rouge Parish, all in the Mississippi delta floodplain, just off the edge of the prairie terrace bounded by Highland Road, provided storage for millions of gallons of water, both local runoff and river flood water, during wet periods of the year. Reports from early explorers in the area describe Bayou Manchac (aka Iberville River) and the surrounding area as seasonably wet and dry, and impassable by boat during the dry  seasons.

For the previous century (20th for you old timers, who still think that the Civil War happened in the previous century), faster runoff from Baton Rouge, caused by the addition of concrete to the ground and the drainage channels, caused concern about the increasing height of floods downstream. Each downstream community approached the problem differently; some raised houses on piers; some raised roads and added bridges over seasonal streams; and some built levees and flood gates. The control structure at the mouth of Alligator Bayou was apparently built in the 1950s to protect property on the Spanish Lake side from flood water from the Bayou Manchac, Bayou Fountain drainage. It was expected to be open most of the time and only closed when needed for protection from flooding.

Over the years, the operation of the gate changed and for the past decade or more, the gate has remained closed most of the time to maintain a relatively constant water level in Alligator Bayou for the operation of Alligator Bayou Tours. Unfortunately, one by-product of that policy was to keep some areas flooded continuously, rather than letting them dry out as they had for hundreds of years. The constant flooding changed the nature of some areas and prevented regeneration of trees in some. Recent compromises have lowered the water level by about a foot, but still hold a large amount of water over some areas.

The current controversy pits some environmentalists, who think that the swamp characteristics should be maintained in the basin because it is useful for children and adult tour participants to see what a Louisiana swamp looks like, against others who believe that protecting the ecological health of the area is best served by trying to mimic natural hydrology, even though years of development outside the basin and years of poor management inside have changed the natural characteristics.

Complicating the argument is the fact that both sides have an economic interest in the battle; Alligator Tours will not be able to operate in much of the year if the Bayou remains at its current depth and the water seeks the level of Bayou Manchac; and de-watering the area for part of the year could improve the health of the forest, or change swamp to bottomland hardwoods, improving the value of the area as a mitigation bank.

Finally, both sides accuse the other of playing politics by pressuring the respective parish governments to support a local perspective on the problem, and lawsuits have been threatened to force the gates to be opened. The face-off currently stands with the Presidents of Iberville and Ascension Parishes agreeing to open the gate to normal changes in water level except for times of imminent flooding, but the controversy will undoubtedly continue for a long time because fortunes hang in the balance.

[ed. note: for more details and opinions on the Spanish Lake issues, read the comments to this post on http://lacoastpost.com/blog/?p=5428]

So what does all this have to do with the Atchafalaya? Well, if you haven’t already noticed similarities with problems in the Atchafalaya Basin, then you probably are new to the area. The Alligator Bayou battle brings home the fact that there is no absolute truth in most environmental arguments; there are only multiple points of view, each with different initial assumptions, different interpretation of facts, different analysis of data, and different conclusions from all of the above. It is usually impossible to sort out an obvious impartial solution because all decisions are subjective.

Delta floodplain drainage basins are, by nature, dynamic landscapes and most will eventually progress through the stages of marsh land to forested swamp to bottomland hardwood, if given enough time and natural overflow conditions. Siltation is a natural process, although modifications to hydrology can increase the rate and location of siltation and forest progression. But progression is not desirable if your intention is to freeze conditions as they are, either for economic or nostalgic reasons.

Most people involved in trying to restore wetlands agree that mimicking natural hydrology, to the amount possible by current conditions, is the best way to give an area a chance at restoring itself. But there are always thorny issues which prevent many changes which would obviously help in that return to historic conditions. In the case of the Atchafalaya Basin, the US Army Corps of Engineers’ management policies for the Floodway are in distinct contrast to any desires to return to historic water flow conditions, and until the Corps admits that dichotomy and attempts to address it directly, either through changes in policy, or mitigation of some of the effects of that policy, it is not clear how much will change in the Basin. Add that to the desires of different interests in the Basin to achieve different stages of wetland or forest usage, and you have a real problem deciding how to “Save the Basin,” which is where i started this discussion.

What is needed in all these situations is a willingness to objectively analyze the big picture and to address the real causes rather than the parochial interests of the individual participants.

Hopefully, the Atchafalaya Basin Natural Resource Inventory and Assessment Tool project being undertaken by the agencies participating in the Basin Technical Advisory Group and being supported by Department of Natural Resources’ Atchafalaya Basin Program and the Coastal Protection and Restoration Authority, will help to shed light on the real problems and issues which need to be addressed in the Atchafalaya Basin. The Tool should help scientists and managers to analyze local water quality issues as well as the effects of water flow modifications on adjacent areas and the Basin as a whole. It could be beginning of the long needed overall Basin Water Management Plan, if we can agree on some definitions…

cr/30


One Response to ““Saving the Basin” – What does it mean?”

  1. gatrtour Says:

    Charles: Thanks for your opinion on this very important issue. I generally agree with most of what you said, but there are some facts that need clarification. The Alligator Bayou Locks have never been used to hold water for our boat tour. We started our tours in 1996 and the water was at 5.5′. We have advocated from our original purchase of 1600 acres for preservation that the water levels should be lowered to restore the ecosystem. The Parish of Ascension was relieved of over 11 wetland violations by the preservation of the land we purchased, and a restoration plan was created that was approved by the EPA. We do not think that Alligator Bayou should be drained – historically (at least 300 years) the bayou always had water in it. Draining the bayou would destroy the basis of the food chain. Wading birds would no longer stay here, alligators will try to find water somewhere, and the ecosystem will very likely suffer from further invasive species. I do hope this issue will help when it comes to the decisions to be made in the Atchafalaya – historical records are invaluable.