The Flow, by Wayne Curtis, Preservation, July-August 2003.
WILL FOSHAG SLIDES OPEN A WINDOW AND PEERS OUT from the second
floor of Heishman's Mill, a stone red clapboard gristmill built by a family
of Swiss Mennonites west of Carlisle, Pa. The Conodoguinet Creek, is a tributary
of the Susquehanna River, is about 150 feet wide where it flows both around
and beneath the mill, and hypnotically smooth sheets of water roar over
a six-foot dam, churning up a white spume that folds back upon itself. On
the this day of spring, the curiously sweet of manure on adjacent fields
wafts past on the season's initial balmy breezes.
It is just the sort of day the first fish return each year. Usually trash
fish like suckers, they make it only as far as this dam, their passage upstream
blocked. "Sometimes," Foshag says, "the water's so thick
with them it almost looks black." But not today. After scanning the
river for a minute or two, Foshag steps back and closes the window. "Maybe
the water needs to warm up a few degrees," he says.
Foshag is not the only one scouting for fish. Biologists and anglers are
watching to see whether the local fish are joined by American shad and river
herring, two migrant species that are native to the Susquehanna and have
been heavily stocked in the Conodoguinet the past several years. If so,
they'll join the suckers, at the base of the dam, frustrated in their attempts
to keep moving upstream.
The mill sits atop a pair of elegant stone arches, though which the water
that powered the works courses. Inside, it's full of unevenly worn boards,
inscrutable machinery, unfilled flour sacks, and great piles of accumulate
matter, some historic, much not. "It's breeding at night," says
Foshag, "I've got to have an auction." The mill processed grain
until 1958, and its machinery though inoperable, remains in place, including
a pair of 1908 water-powered turbines that supplanted a water wheel. It's
one of the last wholly intact mill-and-dam complexes in this part of Pennsylvania,
and since 1969 Foshag, a 74-year-old former helicopter engineer who lives
in the miller's house across the road, has spent much of his time and savings
to keep the mill upright and the dam sound. This effort has involved fending
off floods, fires, rodents, rot, and the unwanted attention of what Foshag
calls "the American teenager."
Largely, however, Foshag has been grappling with a less tangible force that
flood or fire. Advocates for removing dams and allowing fish to migrate
freely have brought their campaign from the main rivers up into the tributaries
and creeks, effectively lobbying to tear down dams from coast to coast.
"What's good for the historic resource is often not good for habitat
and water quality," Giovanni Peebles, the archaeologist with the Vermont
Division for Historic Preservation, explained at a conference on dam removal
in 1999. After nearly three centuries of frenzied dam building, the United
States now appears intent on tearing some dams down.
Anytime the nation finds itself with a focus for demolition, there's a good
chance it's time to sit up and take notice. "The anti-dam people are
powerful and organized and very focused, and the historic preservation people
aren't even thinking about dams," Peebles says when contacted. Preservationists
are accustomed to feuding with developers, not environmentalists. So what
happens when the antagonists are those who are move often allied in efforts
to curb sprawl?
ONCE, DOZENS OF DAMS AND MILLS COULD BE found along this 90-mile
creek, whose head waters lie southwest of here in Franklin County. Cumberland
County, of which Carlisle is county seat, had more than 100 along its waterways
as of 1840, for America was a nation of beavers. Leaders of the early republic
envisioned a country studded with mills that manufactured flour, plaster,
and lumber in communities supporting their own needs close to home. Presidents
George Washington, Thomas Jefferson, and John Quincy Adams all owned mill
works. Wherever a waterway had sufficient drop, you would find a dam harnessing
gravity and putting the river to work.
The Army Corps of Engineers catalogs 75,197 dams nationwide today, including
those built for hydroelectricity, flood control, water storage, irrigation,
and log drives. As former Interior Secretary Bruce Babbitt once noted, Americans
"have been building, on average, one large dams a day, every single
day, since the Declaration of Independence." And that's just dams more
than six feet high. Factor in smaller ones and the estimated total soars
to 2.5 million.
From the outset, millers were well aware their gain came at other's expense.
Dams hindered navigation on waterways, the highways of the early republic.
In 1816, Jefferson wrote approvingly about a Virginia bill that would require
obstructions of navigable waters to return them to their natural state,
but added, "all I ask in my own case is, that the legislature will
not take from me my own works."
Most striking, dams prevented migratory fish from returning to their traditional
spawning grounds. American shad, Atlantic salmon, alewife, and striped bass
are all anadromous, meaning they hatch in freshwater streams, then migrate
to the ocean, where they mature and spend the bulk of their adult lives.
After several years at sea - shad can make as many as five or six trips
between Canada's nutrient-rich Bay of Fundy and wintering grounds off the
eastern seaboard - the fish draw upon navigational skills only dimly understood
by humans and return to the rivers and creeks where they started, heading
upstream to spawn and begin the cycle anew.
Typical of eastern rivers, the Susquehanna and many of its tributaries had
shad in an almost absurd abundance in the 18th century. The fish were so
plentiful in some watersheds that the harvest was limited only by the salt
available to preserve them. Small dams on the tributaries began to hinder
shad runs in the 18th century, and the 19th century the main stem rivers
saw greatly diminished runs only because of obstructions but also because
of declining water quality from mining and industrial pollution. "Poor
shad! where is thy redress?" wrote Henry David Thoreau in the mid-19th
century, lamenting that Massachusetts shad "patiently, almost pathetically,"
swam upriver, "revisiting their old haunts, as if their stern fates
would relent," only to met by the same dam each time.
The situation got worse in the early 20th century, an era of Herculean dam
building. Between 1904 and 1932, four massive hydroelectric dams were constructed
across the lower Susquehanna. Although fish ladders at the new dams were
supposed to assist migrating shad and other species, they were largely ineffective
on such a scale. By 1920, the commercial harvest of shad had ended, and
a three-century epoch drew to a close.
Redress came, somewhat belatedly, with the rise of the environmental movement.
With increasing fervor, clout, and sophistication, activists targeted the
dams that were once the pride of the nation. "Conservationists who
can hold themselves in reasonable check before new oil spills and fresh
megalopolises mysteriously got insane at even the thought of a dam,"
writer John McPhee noted as long as three decades ago. "The conservation
movement is a mystical and religious force, and possibly the reaction to
dams is so violent because rivers are the ultimate metaphors of existence,
and dams destroy rivers."
In recent years, the movement has hit its stride. As McPhee put it in his
latest book, The Founding Fish, "Toward the end of the twentieth
century, the once unthinkable notion of destroying dams went through a surprisingly
swift trajectory from the quixotic to the feasible. " More than 400
dams have been removed nationwide since the early 20th century, since 1995
almost 70 dams have been taken out in Pennsylvania alone, including 25 in
nearby Lancaster County. A milestone of sorts was marked in 1999 when the
Edwards Dam on the Kennebec River in Maine became the first demolished by
the government against the wishes of its owner.
And the aging of the nation's dams will likely do little to stymie this
trend. They typically require major reconstruction work every 50 years or
so, and older dams require more expensive work than newer ones. About one-quarter
of Unites States dams are older than 50 years, according to the American
Society of Civil Engineers; that percentage will increase to 85 percent
A list of benefits derived from dam demolition is long and persuasive. Removal
not only permits the return of migratory fish but also restores the natural
rhythms of the waterway - high water in spring, low water in fall - which
allow it to better flush itself clean than the constant medium flow under
dam control. Dead water above barriers also alters river temperatures and
traps silt and contaminants; slow-moving mill ponds can lack sufficient
oxygen to support aquatic life and thus fragment a river into isolated zones.
Older dams threaten to fail and flood downstream communities, and dams have
an oddly powerful allure for idle teenagers possessed of more bravado than
common sense. "These things are potential killing machines," an
engineer with the Pennsylvania Department of Environmental Protection warned
Where it proves impractical to remove dams that control flooding or retain
drinking water, extreme measures are often taken to restore the fish runs.
For years, shad were captured at the lowest of the Susquehanna's four dams,
then hauled in a fleet of tanker trucks 58 miles upstream to be deposited
above the uppermost dam. Starting in the early 1990's, elaborate fish elevators
were installed at all four, at a cost of some $59 million. And the shad
are returning: OF more than 200,000 make it into the uppermost lift, which
opened in 2000.
Beginning in 1995, hundreds of thousands of shad fry have been stocked annually
in Conodoguinet Creek. Those that survive their migration downstream and
their ocean sojourns, and survive their migration on their return trek,
may soon be keeping an appointment with the creek's head waters. Thanks
to the efforts of the state and environmental groups over the past few years,
the Conodoguinet should be flowing freely and ready to welcome shad this
summer, with one notable exception: Will Foshag's dam at Heishman's Mill.
AT A FORUM HELD AT A LOCAL HIGH SCHOOL IN the late 1990's, state
officials announced that barriers along the Conodoguinet would need to come
out, with or without the assistance of the landowners. "This can be
a difficult process," Scott Carney of the Pennsylvania Fish and Boat
Commission told the audience. "We prefer to cooperate with the dam
owners, but that's not always possible."
"That was when I realized they were serious," Foshag says, "There
was a full-blown fraction beating up on dams. I could identify 20 or 30
agencies involved in fish restoration. I realized I had to do something,
because there was this Niagara of programs coming at me."
The reasons for taking out dams are well known. But what does a community
lose when a dam is torn out? Heishman's Mill is a rare beauty, its arches
and stone-and-wood construction display a lyrical grace and near-perfect
proportions. Here and there, brick and limestone farmhouses and other historic
structures edge the mill pond that extends a quarter-mile upstream. The
tableau is a point of pride not only for Foshag but also for boaters, picnickers,
ice skaters, photographers, and painters. In a publication of heavy-breathing
nostalgic - say, a magazine full of gauzy photos of lighthouses, train stations,
and covered bridges - Heishman's Mill would make an excellent centerfold.
It's straight out of the mythical American experience.
Dam adherents - and are a few - say dams should be preserved not just as
elements in pleasing landscapes. Those that mark the ingenuity of our earliest
engineers should be preserved for future generations to study and admire.
Ted Hazen, a mill restorer and preservation consultant based in Virginia,
points out that removing a dam returns the water channel to its original,
narrower course, and "once you remove the water source from the mill,
it's just a building. It's hard to interpret without the water flowing."
Dams remind us of how our ancestors made a living. Even though old mills,
dams, and ponds may no longer anchor a community economically (major 20th-century
hydro dams excepted), they still impart a sense of identity. "If you
live in a small village and you've been looking at the same landscape for
eight generations, to take that dam out totally alters the character of
your village," says Peebles.
On a tour along the Conodoguinet Creek, Foshag shows me the three most common
options presented for dealing with dams that obstruct fish. About two miles
downstream we visit the site of Burgner's Mill, constructed a little later
than Heishman's Mill, but the stone arches of the two mills are so similar
that Foshag suspects the same person built them. Flood and neglect ruined
the mill long ago, and the mill house burned to the ground in 1960. Traces
of the dam wall extend into the creek, and the great stones of the mill
wall, now tumbled amid ash and sycamore, have been well picked over. "People
are using it as a quarry," Foshag says, This is option one: Let nature
take its course.
Above Heishman's Mill, Black Dam spans the creek at the downstream end of
a narrow island covered with scrappy brush. In its most recent incarnation
the dam provided electricity for a nearby trolley company. When the water
drops a bit this summer, backhoes will move in and take out the dam. Option
two: Let the environmentalists take their course.
At the Cave Hill Dam on the edge of downstream Carlisle, we see option three:
Build a fish ladder. The dam is part of the city water works, so demolition
wasn't realistic. A concrete fish ladder was constructed along the south
bank of the creek in 2001. The ladder consists of a channel about four feet
wide, which, like a wheelchair ramp, extends along the shore, and then doubles
back and upward, connecting to the top of the dam. Water sluices through
the channel and over wooden baffles, and we spot some fish entering the
complex near the base of the dam.
This is known as a Denil Fish way, designed nearly a century ago to serve
a noble purpose, but its aesthetics have the appeal of a Soviet-era public
works project. "As you see, it's not a good fit for Heishman's Mill,"
says Foshag, "or for any historic site, for that matter."
When state officials proposed a similar fish ladder for Heishman's Mill
a few years back, Foshag realized he had to act if he was to avoid the indignity
of having an "enormous and very expensive thing glued to the side of
the mill." First, he moved to have the dam placed on the state's historic
registry. (His application to the National Register is still in process.)
Then he turned to the Internet and fisheries research libraries. Hunting
for overlooked alternatives, he learned that under the right circumstances,
another option did exist - one that might please anglers, fisheries, biologists,
historic preservationists, shad, and himself.
The potential solution, which he discovered in a German language publication,
is sometimes called a nature-like fish passage (also naturalized fish way,
semi natural fish way, riffle-pool fish way, and bypass channel, among other
names). the concept is based upon "physiomimesis," or the copying
of natural systems. In other words, it's an artificial creek.
Virginia millwright Hazen says that he has seen spring overflow naturally
around a dam and over adjacent land during exceptionally high water; if
the channel was deep enough, fish migrated through it and around the dam.
"Standard fish passageways look more like dams than like the river,"
says Laura Wildman of the Glastonbury, Connecticut, office of American Rivers,
which lobbies for dam removals. "If you design a fish passage facility
to look like the river, then the fish will be more familiar with the environment,
and you'll attract a greater variety of species and life stages."
Wildman adds that her group prefers to see dams removed, since a fish bypass
doesn't fully restore the waterway. "The river is dynamic and wants
to move," she says. "Dams lock it into position horizontally and
vertically. But when you can't remove a dam, there can be a good option.
There are lots of historic sites where that might be more appropriate. The
social value may outweigh the environmental."
The fish passage approach is common in Germany, Austria, and parts of Canada.
Although a bypass channel can cost about one third as much as a traditional
fish ladder and precedents can be found in New England, Colorado, and Minnesota.
Foshag encountered skepticism from the state. But with some tactical prodding
from Sara Nicholas, the Harrisburg-based representative of American Rivers,
the idea started to take root and grow. State officials now view it as an
exciting pilot project that might work at other dams. The estimated cost
of the project is $90,000, which has been raised through private and federal
grants and in-kind donations, and construction is scheduled to begin this
Every foot of the dam height requires some 100 feet of fish way coursing
through adjacent lands; Foshag's dam was blessed with low, open land across
the creek from the mill and landowners who agreed to having a fish way built.
But success isn't a forgone conclusion. Although many fish have easily adapted
to bypass channels, "It's pretty much experimental for shad and herring,
which are very sensitive to being distracted or disturbed during their migration,"
says Carney at the state Fish and Boat Commission. "Every indication
is that (the bypass channels) will work fine, but the proof is in the pudding."
The task facing preservations worried about losing dams in increasingly
less technical and more philosophical and political. How man dams should
be preserved, give the environmental damage and disruption they cause? How
do we decide which dams are worth preserving? Peebles says that Vermont
has made strides toward resolving those vexing questions. After state preservation
officials squabbled with natural resources officials over a dam in 1996,
Vermont established a task force to preempt such conflicts. The panel meets
quarterly to exchange information and started an inventory of dams in the
state - their age and condition, the affected landscapes, and their role
in the community. "The idea was to gather biological and cultural information,"
Peebles says, "We're making progress in have a good dialogue, and we're
letting groups see that there's another side."
If all goes well, next spring will find Foshag watching fish, possibly shad,
return, take a looping detour through the adjacent fields, and swim toward
head waters that have been off limits for two centuries.
Original Picture Captions:
1. For 200 years a dam has diverted water to Heishman's Mill but blocked
fish from the headwaiters of the Conodoguinet Creek.
2. Will Foshag, below, at Heishman's Mill; opposite, nature and scavengers
have claimed all but traces of the dam downstream at Burgner's Mill.
3. Removal of dams not only permits the return of migratory fish but also
restores the natural rhythms of the waterway.
4. Designed nearly a century ago to serve a noble purpose, the fishway's
aesthetics have the appeal of a Soviet-era public works project.
5. A stone arch, above, contributes to the grace of Heishman's Mill; a Denil
fish way scales Cave Hill Dam, opposite.
© 2003 Wayne Curtis, All rights reserved. Do not repost or republish
without permission from author.
Originally printed in Preservation (July/August 2003), the magazine of the
National Trust for Historic Preservation.
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