Old Dams and New Realities
(2004-01-29)
An Outdoor Column From: Tom Conroy DNR Southern Region Information
Officer 261 Highway 15 South New Ulm,MN 56073 507-359-6014 tom.conroy@dnr.state.mn.us
January 29, 2004
Sack lunch and fishing pole in tow, we?d hop on
our bikes and start pedaling our way out of town. In 15 minutes
we?d be at the dam where we?d swim, fish and just plain lolly-gag
the afternoon away. Not until we heard the factory whistle blow
did we head back to town for supper. That was many years ago,
back when kids were left to their own devices and parents trusted
they?d be safe on a lazy summer day. That factory whistle stopped
blowing years ago and the gravel road we biked is now blacktop.
The dam, however, remains. It?s a small dam, as dams go, on a
stream so narrow you can jump across it in many places. The pool
upstream of the dam has long since filled in with sediment. The
dam no longer serves a purpose, if it ever really did. Admittedly,
I have a sentimental attachment to that old concrete structure.
Lots of good childhood memories were created there. Then again,
I?d have those memories even if the dam were removed. And some
day it likely will be. When it is, fish will once again have a
whole new stretch of stream to navigate. The purpose and impacts
of dams in Minnesota have come under increasing scrutiny in recent
times. We now know that while some dams are good, others are not
all they?re cracked up to be. And cracking, many literally are
as they age. The DNR does a considerable amount of work with dams.
Sometimes we advocate taking them out, and other times we advocate
putting them in. Understandably, the public can sometimes get
confused. A little history can help clarify. Most river and stream
dams in this country were built between 1900 and 1949 for the
purposes of generating power, grinding grain, providing water
supplies and recreation, as flood control structures, for fire
protection and irrigation, and to foster development. The average
life expectancy of a dam is 50 years. Over the next 15 to 20 years,
more than 80 percent of those dams will be past that age. As these
dams age and no longer serve the purpose for which they were built,
the costs of maintaining them become more and more prohibitive.
Additionally, they can pose a safety hazard, hinder navigation,
and prevent fish from migrating upstream as they search for spawning
areas and deeper water for over-wintering. These are the types
of dams that Minnesota and many other states are now removing
in increasing number in order to re-establish natural, free-flowing
streams. Conversely, the DNR sometimes promotes the construction
of other types of dams. Water control structures, a fancier name
for certain types of dams, are encouraged on various wetlands
and lakes. These dams allow water levels to be manipulated to
encourage vegetation growth vital to clean water, fish and wildlife.
That old dam outside my hometown long ago outlived its usefulness.
It is now nothing more than a hindrance to fish and other aquatic
species that depend on free-flowing stream habitats for their
existence. Like the factory whistle in town, this old dam will
one day also cease to exist. The memories, however, will live
on. -30-
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