Defining Your Project - Project Planning and Management for Ecological Restoration - page 31

Box 3-1. Restoration Project Highlight: Test Trials of Restoration Approaches
Can Reveal the Most Cost-Effective Methods for Large Degraded Areas
Project: Invasive Tree Removal and Wetland Restoration in Barataria Preserve; Jean
Lafitte National Historic Park and Barataria Preserve, Louisiana, United States
Before the current Barataria Preserve was established, the Jean Lafitte National
Historic Park contained numerous construction activities—ranging from a failed res-
idential community to oil exploration to pipelines—that altered the wetland topogra-
phy and interrupted the wetland hydrology. A series of canals that had been excavated
for pipelines, oil exploration, and various other activities occupied some twenty miles
of waterways. The spoil from the excavations was commonly cast on either side or
both sides, depending on the purpose. These spoil banks ranged in width from twenty
to eighty feet with a height of from two feet to almost eight feet.
In effect, an upland habitat was created in a wetland as a long linear habitat cross-
ing a large portion of the preserve. Invasive plants were able to establish in these new
upland areas, with the Chinese tallow tree the most dominant. But the effects of the
invasive species were not as significant as the interruption of the water flow through
the wetland. The spoil banks created numerous locations where the altered hydrology
seriously impacted the native vegetation and function of the wetlands.
Louisiana State University, working with the National Park Service, conducted
test trials on the most effective way to remove the spoil banks and fill the canals. The
trials involved testing two approaches. The first approach was to place spoil into the
adjacent canal with supplemental material dredged from a nearby lake, in an effort to
return the watercourse to its original elevation. The second approach was to use only
the spoil material and leave the watercourse in a shallow but not original condition.
Monitoring of the two channels provided data for future restoration work. Although
some differences existed between the two approaches, the decision was made not
to import any further dredge material. Factors leading to this decision included the
added cost (approximately eight times more expensive) and various logistical issues
of transport and access. When funding became available through the American Re-
covery Administration, the preserve was able to obtain sufficient funds to convert 4.4
miles of canals to shallow water habitat and reestablish normal wetland hydrology to
that area of the preserve.
The outcome of the construction went as anticipated; however, not anticipated
were impacts to various visitor groups in the preserve. The preserve is open to hunt-
ing, trapping, and fishing as well as recreational boating. The construction work
did interfere significantly with hunting activities. The tree removal, spoil bank
excavation, and partial refilling of the canals was deemed an overall success, and
the preserve is seeking more funds to work on the remaining ten miles of canals.