View
215
Download
0
Category
Preview:
Citation preview
7/27/2019 IowaOutdoorsDrowningMachine (1)
1/4
36 Iowa outdoors may / june 2009
T Ct Stt D s pplspt f fs Ds ms.
Its a terriying way to go.
Trapped below a dam, victims fnd themselves
fghting currents rom both upstream and downstream.
Typically, they are sucked under water, pop back up and
are carried back toward the ace o the dam. This can happen
repeatedly until the victim succumbs.
For many amily members and riends o these victims,
the circumstances seem completely random. In act,
though, drownings at low-head dams are completely
predictable. That is why a low-head dam is commonly
known as The Drowning Machine. In the past 10 years,
low-head dams killed 1.4 Iowans per year. They accounted
or approximately a quarter o the documented drownings
on Iowas rivers during that period.
Low-head dams are where the vast majority o dam-
related deaths occur, not at large reservoir dams with
intimidating outlows. Survivorssay the drop looked tiny,
and the orces at play came as a complete surprise.
Rescue proessionals have known about this hazard
or decades. Translating that knowledge into wider public
7/27/2019 IowaOutdoorsDrowningMachine (1)
2/4
www.Iowadnr.gov 37
STory anD PhoToS by naTe hoogeveen
policy has taken longer. In a 1981 article or the Iowa
Conservationist, written ater a wave o rescue personnel
nationwide drowned while trying to rescue people rom
dams, Water Saety Coordinator Betsy Maleug estimated
that ive Iowans became trapped in dams every year.
There were approximately 30 more low-head dam s on
Iowa streams at the time.
Public education continued through the 1980s and
1990s, but no standard signage system was developed
to warn the public about dams. Dam owners were not
encouraged to post warnings. No inventory o drowning-
hazard dams had been conducted since 1979. No clear
policy toward dams existed, other than to periodically
warn the public.
In 2007, the number o dam-related deaths statewide
spiked to six, catching Iowans attention. In 2 008, the
Iowa General Assembly established the Low-Head Dam
Public Hazard Program, which put into law a program
the Iowa DNR had begun two ye ars prior. The program
provides unds or warning signs, portages around dams
7/27/2019 IowaOutdoorsDrowningMachine (1)
3/4
and cost-sharing to make the structures saer or remove
them where possible.
The legislature also instructed the DNR to launch
a statewide planning process to prioritize water trails
and low-head dam saety with input rom the public and
various experts, including rescue personnel, engineers,
river scientists and fsheries biologists. Dams are beinginventoried or whether they still serve their original
unctions, and or any additional unctions they may perorm.
Beyond saety, a number o issues surround
dams. Many o them limit biological productivity
by separating streams into smaller, less diverse
ecosystems. Then again, some dams act as important
barriers to invasive species. For example, silver carp, a
leaping ish with a voracious appetite, recently invaded
the Missouri River. Dams on the Little Sioux River are
likely the primary reason these ish havent entered
the Iowa Great Lakes system, where they could be
a serious nuisance. Other dams, with the pools they
create, may assist the downstream spread o invasive
zebra mussels.
Other dams back up large reservoirs, such as Red
Rock Lake or Coralville Lake, which serve lood control
and major recreation unctions. Many o them orm
popular local ishing holes.Its sometimes assumed that simply removing dams
is the preerred solution. Maybe, maybe not. Sediments
locked behind the dam may be a problem i released.
Inrastructure like bridges or water supplies may be
upstream. Careul analysis is needed beore settling
on a solution.
In some cases, the best scenario may be re-designing
dams with a rapids downstream, to eliminate the
Drowning Machine eect and restore biological
connections that ish and mussels need to access habitat,
eeding areas and nurseries. This does little or silty pools
38 Iowa outdoors may / june 2009
ABOVE: Pddl Dck hwd lcs s kk sf dstcdwst f t d t adl t rcc r. edds c pllsll cft pst t t fc f t d f lcd t clsdwst. LEFT:Tsds f t fs tt ptd t tpst d t Flds f 2008. Ts fs c tppd tc spllw t t Slll D t f Ds ms. excptf sl l ctfs tt w lctd Dnr stff, ll ts fstll t f x d dd. RIGHT:W s stlld
t t b Wtwks d ft t dw f m Plck,pctd ppst lw t. L t lw-d ds dsft t www.wwtwt..
7/27/2019 IowaOutdoorsDrowningMachine (1)
4/4
www.Iowadnr.gov 39
out of sorrow, survIvors warn of the unknown trap
by ann Cannon
it ws sppsd t f Sd ft t . T
st ssts pt t ts t Ds ms r. Wt t
ddt kw ws tt tp l d.
T dp -ff ws slt lttl t ftd ddt
lookds. bt t l wt lw t d plld t
w d d ld t ts ct. Tw scpd
wt t ls; m Plck dd t. S d
cscsss. S ws ts ds ltst ct.
m c sttstc. bt i kw s s c .
S ws t d st sst. all f t
w t tt d st ssts. m dtd
f vll h Scl Wst Ds ms 2002. i m 2006
s dtd wt kt d f iw Stt. S
ld c t Ccls t sktll d ftll s,
d tl wt fds. S d tt-kt fl.
m d i d ts. W spt s tlk t
s, clsss d pts. m ws fll f lf d l d
lt. jl 9, 2009, ks t td s f dt.
Ppl ft ccld tt d cts dk. bt
m dt dk. h p stk ws spl
w f t ds dwt cts ds ct.
i ld tt dt ws t st flk. Ts tc t
pps css t stt wt t-k lt.
i kw i dd t t fd d t ld. i tk t
spslt t c d f t iw Wtwt
Clt, wc dcts w slts t lw-d ds.
it ls d w f t css. T ws t
Wtl sss ragbrai w dwd t sll d
t idpdc 2007. i 2002, t ws St ns w
kkd t Sctt Stt D Ds ms d dwd.
T dlcs f t d w s pwfl tt s d ws t
ds t t f t d d ws ld fst tl lst
wk lt, w t d ws cd sl ls w. hs
fl d fds w fll l t d t wkl l t
t st d ld fl. h ws t t f jl mkl,
fllw d f t iWC.
i fd sps t s tw cll stdts
tls fltl ft scd ft 30 w ts
stl st t dlcs t t s Ds ms d.
o t ddtl dw t lt t s f 2007.
nw wt ms dt, t s pttl t k
cs f d t d pssl cs t lt
f ts ds ds. W c l w dstd
ts pl, dct d ddss sft pls t s
ds. m p s tt ppl wll t ld, d tt
t ft, ts zd wll dstt .
Ann Cannon formerly
served with Iowa DNRs
AmeriCorps program,
and worked as an
interpreter at Maquoketa
Caves State Park and
as an assistant with the
wildlife diversity program.
a C, lft, wtm Plck.
0
1
2
3
4
5
6
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
IOWAS DAMRELATED DEATHS, 1999 2008
upstream, but may be the most acceptable solution or a
given community.
Midway through the planning process, it has become
apparent that individual dams will require unique
solutions. In some cases, proposed saety solutions will
be warning signs and other measures such as cabling or
railings. In others, physical modiications to the damswit h accompanying river restoration wil l be preer red.
But its increasingly clear that many communities are
interested in mitigating the hazards and restoring rivers
whe re possible.
Nate Hoogeveen is the River Programs Coordinator
for the Iowa DNR.
Wd l t w t tk. S d s pt f
sttwd pl t http://creekcommunities.design.
iastate.edu/Water_Trails.html.
Recommended