Wetlands form where rainfall, floods, or tides saturate the
ground every so often. They crop up in low spots where groundwater
burbles and in wet spots left behind by rivers or streams as they
shift course over time. Because these areas usually provide habitat
for a wide range of wildlife and help to absorb floodwaters,
government agencies seek to protect these lands. But such
protective policies often conflict with expanding
When it comes to balancing preservation of wetlands with vibrant
coastal growth, Section 404 of the Clean Water Act seems promising:
Developers who destroy wetlands can compensate by creating or
restoring them somewhere else. In practice, however, the policy has
some serious shortcomings. Proposed new regulations hope to amend
those, and in the meantime, the science of wetlands restoration has
made strong advances. In the long run, the chance of new or
restored wetlands surviving increases dramatically when you have
the right expertise.
Since Congress passed the Clean Water Act in 1972, the U.S. Army
Corps of Engineers has let developers who must destroy wetlands
pursue "compensatory mitigation." What that means is creating,
restoring, enhancing, or — in unusual cases —
preserving other wetlands. The policy can come into play for
developers draining as little as one-tenth of a wetlands acre that
is deemed connected to navigable waterways. Any destruction of such
wetlands requires compensation in Florida and some other
Mitigation, which historically has required developers to create or
restore more wetlands than they destroy, was supposed to contribute
to "no net loss" of the nation's wetlands. But scientists and other
experts who have examined the policy's impact agree it has not
lived up to expectations. A National Academy of Sciences committee
determined in a 2001 report that mitigation projects often fail to
meet the conditions of their permits or — worse yet —
don't get completed at all. The report concludes: "The goal of no
net loss of wetlands is not being met for wetlands function by the
mitigation program, despite progress in the last 20 years." Studies
of wetlands mitigation in New Jersey, Ohio, and California have all
arrived at decidedly mixed conclusions, however.
Meanwhile, through at least the late 1990s, the nation's wetlands
continued to shrink. In a periodic report on wetlands status and
trends, the U.S. Fish and Wildlife Service estimated the annual
loss at 58,500 acres between 1986 and 1997. That was less than in
previous decades but augmented historical losses: Two centuries
ago, wetlands covered 221 million acres of the continental U.S.
Just under half of that acreage remained by the 1980s, according to
a U.S. Geological Survey study.
Smaller "postage stamp" wetlands are more difficult to restore,
but there are many success stories. The key is to contract with a
company that will work with the builder from "cradle to grave." A
living wetlands, such as this one shown nine months after
restoration was completed, is not something that can be torn apart,
rebuilt, and then turned loose to thrive on its own at the end of a
Compensatory mitigation may be flawed, but it is not hopelessly so,
insist many scientists and environmental managers. They lay the
blame for the policy's shortcomings on lax data collection and
oversight by the Army Corps of Engineers. But they also say
mitigation's faults are tied to a major failing in the program's
implementation: namely, that permitting guidelines have
traditionally favored on-site compensation — creating or
restoring wetlands near development and urbanization — rather
than off-site compensation in areas where wetlands are more likely
Proposed new regulations seek to address that, says Ann Redmond,
regional manager for ecological and water resources at the
Florida-based engineering and environmental planning firm
WilsonMiller. Redmond spent 12 years as Florida's top mitigation
specialist in the 1980s and 1990s. She also served on the National
Academy of Sciences panel that issued the 2001 report.
The problem with on-site mitigation, Redmond says, is that for
projects without a large amount of land, created or restored
wetlands are often likely to fail. Building and development may
have altered the groundwater table, meaning the wetlands get too
little or perhaps too much water. Plus, wetlands in urban settings
are more vulnerable to invasion by exotic plants, she explains.
Both problems are aggravated by lax maintenance. Federal law
requires maintenance, but compliance is more difficult to confirm
for "postage stamp" wetlands. And some key techniques, such as
fire, may not be possible in small or urban parcels. Managers may
use fire, Redmond says, to kill off shrubs or trees that are slowly
taking over plant-filled wetlands. "If we didn't burn anything, all
of our herbaceous systems would go to forest," she explains.
Redmond adds, "Dozens of studies have shown that for freshwater
wetlands mitigation, there is a very low success rate of trying to
create wetlands in urban and suburban settings, and there's not
even a great amount of success for restoring wetlands in those
settings. If you want mitigation that will succeed and be
substantial and part of the long-term infrastructure, usually you
need to go to an off-site area where you know the hydrology will
remain intact and where you can use fire and other management
techniques to manage the property."
Even though Section 404 has long allowed developers to meet
mitigation requirements off site, the corp's guidelines have made
that choice more difficult. The new rules encourage a form of
wetlands conservation called "wetlands banking" and emphasize that
managers make decisions based less on localized topography than on
"The biggest change is that we are now directed to look at the
likely long-term sustainability of the wetlands mitigation
project," Redmond says.
The shift may implicitly acknowledge that off-site mitigation is
becoming a more common solution despite the permitting roadblocks.
One increasingly common vehicle is the "mitigation banks" —
wetlands that have been restored expressly for purposes of
compensation. Usually, the government grants the mitigation bank
(whether publicly or privately owned) credits for every restored
acre, and the bank sells those credits to developers who must
compensate for losses.
The number of wetlands banks has increased 78% from 1991 to 2005,
with 405 such banks operating today, according to a 2005
Environmental Law Institute report. In Florida, one of the states
where wetlands banking is most common, there are 118,000 acres of
wetlands in mitigation banks currently, compared with just 19,000 a
decade ago, notes Victoria Tauxe, environmental manager for the
mitigation section in the state Department of Environmental
This wetlands in Sarasota County has been scraped to a level
about 6 inches below the final grade. After this, a layer of
organic matter will be laid in to provide a seed bed before the
coffer dams are released at low tide to allow water to flow into
Critics worry that wetlands banks or other large isolated
mitigation areas mean too few wetlands in urban areas that need
their flood control and water recharge functions. But banks and
other large mitigation areas have a number of advantages. One, they
make it easier for regulators to verify compliance. Two, they have
a stronger likelihood of surviving. Experts agree that small
wetlands created on former uplands are particularly prone to fail.
"We want to replace wetlands where wetlands should be," Tauxe
Finally, large mitigation areas by virtue of their size may offer
more of the environmental benefits of wetlands, such as nurturing a
variety of wildlife and sopping up pollutants.
Will the shift toward wetlands banks or other large tracts make the
new regulations more successful than their predecessors? Only time
will tell, but Redmond says management will be key. For Redmond,
it's imperative that owners of banks or other large wetlands,
whether they are public or private, treat their wetlands "like
state parks," with staff members removing exotic plants and
performing other regular maintenance. "You've got have somebody who
loves it," she says.
Whether restoring a wetland on site or in a wetlands bank, the
science matters. Any developers embarking on this course need to
understand which details matter most, explains Tom Ries, vice
president and director of land management for Scheda Ecological
Associates, a Tampa-based environmental consulting firm. Ries
routinely heads up restoration projects for developers trying to
satisfy federal, state, or county regulations. Before he joined
Scheda, he spent nine years at the Southwest Florida Water
Management District. A veteran of an estimated 50 wetlands
restorations, his projects have won 22 environmental awards.
Ries agrees with critics who contend that mitigation often fails.
But he says the idea is not flawed — it's the execution that
is often the problem. "There are success stories out there," he
says. "It just has to be done right."
The trickiest part of building wetlands is getting the
hydrology right — knowing where the water is and how the
available soils will drain to ensure a continual measured amount of
water to support wetlands plant life. Wetlands engineer Tom Ries of
Scheda Ecological Associates often must rely on historical data,
such as this aerial soil map originally compiled by the Natural
Resources Conservation Service to assist farmers.
Hydrology. The most obvious and important ingredient is
also the trickiest: water. Too much of it means a pond; too little
and native wetlands plants don't grow, or die. "Ninety percent of
the reason that wetlands fail is they don't get the hydrology
right," Ries notes.
For this reason, saltwater wetlands are by far the easiest to
restore, Ries explains. Tide tables and a visual survey reveal
where the shore is regularly inundated, making it clear where to
plant mangrove, cordgrass, or other saltwater plants. He even plans
for sea-level rise by shaping the shore into a gradual slope so
plants can migrate landward. "There's no excuse for not making it
work in a tidal environment," he says.
Getting the hydrology right for freshwater wetlands is another
matter entirely. Human activity has often so altered a site that
original streams, ponds, or wetlands are no longer visible, Ries
notes. So he consults decades-old aerial and terrain surveys
originally compiled by the Natural Resources Conservation Service
to assist farmers.
"If you go back to the first soils books that were done in the
1940s and '50s, before the site was altered, you get an idea of
what's what," he says.
The photos and surveys may reveal filled-in or much-diminished
wetlands, which could indicate a promising spot to create or
restore one. The surveys may also reveal historic groundwater
levels during Florida's wet summer and dry winter seasons. The
obvious next step might seem to be removing enough of the soil to
return the site to its old elevation, but it's usually not that
simple. Buildings and parking lots may have reduced the amount of
rainwater percolating down through the soil to recharge the
groundwater. Too, reshaping of the land may mean that groundwater
no longer flows in its historic direction. So Ries has to figure
out the current groundwater scenario. The best method is to monitor
a network of water-table-measuring piezometers for at least a year.
With a more urgent deadline, it's possible to get a grasp based on
lichen and plant growth, Ries says.
"This is the hardest thing," he admits. "We need to get a good
assessment of where the groundwater is today."
Scrape and seed. The next step is to "scrape" the
site to the proper elevation for wetlands to flourish. It's crucial
that the contractor overseeing the bulldozers get the numbers
right. "You can be off a few tenths or a half of a foot, and that
makes all the difference in the world as to whether it's going to
make it or not," Ries explains.
Then it's time to seed the site with wetlands plants. Ries says if
a developer is destroying a quality wetlands, Ries may save the
soil as a good source of seeds for the mitigated wetlands. If he is
designing a freshwater plants wetlands, he plans for about 5,000
plants per acre, selecting from dozens of candidates, including
pickerel weed, duck potato, and maidencane. For treed wetlands, the
number is about 480 trees per acre. He plants irregularly when he
can, to more closely approximate natural wetlands.
Monitoring and maintenance. Ries says
agencies require a minimum of three years of monitoring and
maintaining plant wetlands and ten years for forested wetlands.
It's especially important to keep nonnative plants out when the new
wetlands is maturing. "Hopefully within one or two years, if you
did everything right, you've helped the native plants to the point
they can outcompete nonnative wetlands plants," he notes.
Monitoring wetlands requires three things: documenting all
plant life, measuring water levels, and documenting wildlife
utilization of the area, if applicable. Here, Kathleen Barrett, a
senior environmental scientist, works at the first stage of
monitoring to sample new plant life at the edge of a quadrant at a
Costs. The process isn't cheap. Depending
on the size of the site, Scheda charges from less than $1,000 to
$5,000 for a feasibility study. The cost of designing for
mitigation and applying for the relevant permits ranges from
$12,000 to $50,000, again depending on size (this step is called
the UMAM, an acronym for Unified Mitigation Assessment
Methodology). Actual mitigation usually runs around $50,000 per
acre. Maintenance and monitoring adds an additional annual $3,000
How can a developer or builder make sure he spends wisely? First,
Ries says developers should hire an environmental consulting firm
to manage the entire project from start to finish — not just
the assessment, permitting, and design portion, which is far more
typical. "We're always pulled in like a surgical tool: ‘Come
in here and help us get a permit and design mitigation. OK, see
But if something goes wrong, expect a blame game among the
designer, the contractor, and subcontractors hired to plant or
maintain the wetlands. "It's really important in my opinion for a
developer to get somebody from cradle to grave, because then
there's no finger-pointing," Ries explains.
Second, Ries advises developers to learn the basics of mitigation
and actively scrutinize and question environmental consultant's
plans. "Developers could point out errors themselves," he says.
"They really should get educated in this." ~
Aaron Hoover writes on science and the
environment from his home in Gainesville, Fla., and is a regular
contributor to Coastal Contractor. Photos courtesy of Tom Ries,
except as noted.