Below are the answers to the 10 photos posted last week as CFWEP's "Know Your Noxious Weeds" Quiz. I've got good news and bad news. The good news is that my job was very easy in that NO ONE tried out their noxious knowledge...zip, nada, nothing!!!?
Of course, the bad news is that we don't have any winners in the War on Weeds and we still have a whole pile of CFWEP stickers to give away.
Don't worry, we'll have more quiz opportunities for you in the future. Hopefully we'll get some participants on the next one!!!
Knowing your noxious weeds is important, as a landowner, a sportsmen or just part of being a well-informed citizen. Here are the answers to the quiz, along with a little extra information on each one:
1. Baby's Breath; NOXIOUS. This pretty, but not too pretty ornamental is commonly seen in floral arrangements. Unfortunately, like a lot of "pretty ornamentals" it is also HIGHLY INVASIVE, especially in disturbed areas. Baby's Breath is not on the Montana Noxious Weed list, but it's a big enough problem in Butte that it's on the Silver Bow County noxious weed who's who. See a vacant lot in Butte? Then chances are, you're probably looking at Baby's Breath too.
2. Houndstongue; NOXIOUS. Houndstongue is a growing problem in a lot of riparian areas and is a Category 1 (that's BAD) Montana Noxious Weed. A native plant to Europe, it contains a toxin that causes liver cells to stop reproducing. And if that's not bad enough, have you ever been "licked" by a houndstongue? If you've ever come home or back to your car from a walk and found dozens of little burrs sticking to your socks, shirt, pants, waders, pretty much anything...YOU'VE BEEN LICKED! Make sure you remove the burrs before going somewhere else: these are the plant's seeds and we don't want to give houndstongue any help in spreading.
3. Spotted knapweed: NOXIOUS. By far the most infamous of Montana's noxious weeds. Category 1: 'Nuff said. If you don't recognize this one, chances are you are a noxious weed yourself.
4. Matrimony Vine; NOXIOUS. This is another one of Butte-Silver Bow's noxious weeds. A strong colonizer of mining contaminated and disturbed areas, this bushy shrub is a beautiful specimen of a noxious weed. It's bright red-orange berries are a spectacular contrast to the pretty purple flower in the photo, and it provides a great source of food and excellent habitat for a variety of song birds and small mammals in Butte, like the feral cat. However...(with noxious weeds, there's always a "however")...the reason this member of the nightshade family got its name is fairly simple: once you have it, you're married to it, so to speak. Its hard to get rid of and it has a unique penchant in the Butte area to find a crack in a vacant building (many times in occupied building's too) foundation and quickly fill the entire basement, attic or any other available living space with bush.
5. Bitterroot; Not Noxious. Also called "rock rose" the bitterroot as you should know is Montana's state flower.
6. Field bindweed (aka Morning Glory); NOXIOUS. Another pretty but dangerous plant. Field bindweed, a member of the morning glory family, forms thick mats along the ground in a lot of pastures and other disturbed landscapes. It, like knapweed and houndstongue, is a Category 1 Montana Noxious weed.
7. Plains Prickly Pear; Not Noxious. How would you like to go for a barefoot jog across a prairie full of this sticky fellow? John Colter did. One of Montana's only native succulents, this cactus has a showy yellow bloom early in the summer (June).
8. Truffula Tree; Not Noxious. For those of you who are Dr. Suess fans, here is the victim of Geisel's classic book, The Lorax. "The touch of their tufts is much softer than silk and they have the sweet smell of fresh butterfly's milk." I have yet to find one growing in Montana.
9. Leafy Spurge; NOXIOUS. Because of its ridiculous invasiveness and the even more ridiculous difficulty in controlling its infestations, Leafy Spurge just might be Public Enemy No.1 when it comes to noxious weeds. Spurge can "pop" its seeds several meters and its roots have been documented to extend as deep as 20 feet into the soil. With these two methods of invasion, spurge is one tough customer, earning it a Category 1 listing.
10. Purple Loosestrife; NOXIOUS. This is a Category 2 Montana Noxious Weed list. A riparian invader, it is also a "pretty" noxious species, another escaped European ornamental. You can see from the photo that when loosestrife finds an area it likes, nothing else stands a chance.
These are just a handful of the weeds that are marching their way across Montana. I strongly urge you to spend a few minutes on the Department of Agriculture's Montana Noxious Weeds website at http://agr.state.mt.us/weedpest/noxiousweeds.asp . There is lots of interesting information here, as well as a list of contacts who could come to your class to help you learn more!
That's it for the quiz...
As a fun exercise to get your in-quiz-itive minds in shape for CFWEP's next test, I invite you all to take the Fish, Wildlife and Parks' easy to use, on-line Bear Identification test. Here's the link: http://fwp.mt.gov/bearid/default.html
It's somewhat of a secret (maybe it's not), but most mountain ranges in western Montana have at least some grizzly bears. The FWP quiz is a requirement for anyone wanting to hunt black bears. But it's also a good test of your bear identification skills. Is it a black bear or a grizzly? You need an 80% to pass...See how well you do!
Friday, April 20, 2007
Wednesday, April 11, 2007
"Know Your Noxious Weeds" Quiz
Just for fun, below are 10 photos of plants. Identify them all and tell us which ones are listed as noxious weeds in Montana and which ones are not. (Note: they may not be on the state weeds list, but all of the noxious ones pictured below are on at least one of the 56 counties' lists.) Name and list all 10 correctly, and you win a CFWEP sticker!! Not to mention, you'll be a little bit more the wiser in the endless "War on Weeds."
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Good luck! When you think you have all the answers, send them to me at mvincent@mtech.edu (be sure to include your mailing address if you want a sticker!). I'll post the answers...and our winners, next Friday.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Good luck! When you think you have all the answers, send them to me at mvincent@mtech.edu (be sure to include your mailing address if you want a sticker!). I'll post the answers...and our winners, next Friday.
Tuesday, April 10, 2007
Noxious Weeds: Where Are They Going To Show Up NEXT??
This column we are pleased to welcome our first guest blogger: Soil scientist Tom Keck of Bozeman. Keck received his PhD in Soil Science from Montana State University in 1998 and was the lead field scientist for several years collecting the data for Silver Bow County's soil survey. He currently works in Bozeman as a Soil Scientist for his own company, Northern Rockies Soil and Water. Tom is also a valuable cooperating scientist with CFWEP, helping improve place-based science education in the Clark Fork basin as a summer teacher training instructor (see photo). If you're reading this and are a scientist living or doing research in the Clark Fork and would like to contribute a guest blog, drop me a line at mvincent@mtech.edu . We'd love for you to help us spread science through the valley!
In the “War on Weeds”, spotted knapweed and leafy spurge stand out as the major weed control challenges in Silver Bow County. Each weed has infested thousands of acres in the county and there is potential for them to infest even greater acreages.
Weed infestation reduces property values, increases soil erosion, reduces areas’ ability to support wildlife or domestic livestock and presents tremendous weed control costs. Countywide, the government currently spends nearly $400,000 annually on weed control efforts; this does NOT include additional costs that individual landowners pay to control weeds on their own. Noxious weeds are an expensive issue to say the least!
Weed species often appear to be everywhere in infested areas. Spotted knapweed in the Butte area provides a good example. Once you learn to identify this species (pictured below), it seems to be growing everywhere you look. On closer inspection, however, you can find areas in and around Butte where spotted knapweed is not doing so well. There are many sites where it is completely missing, while in other areas, native plants are at least holding their own against the noxious invader.
An ongoing study funded by the Mile High Conservation District through the Conservation Districts Grant Program has been using field data from numerous locations in Silver Bow County to look at patterns in the distributions of spotted knapweed and leafy spurge relative to landscape, plant community and soil properties. The study looks at habitat preferences in existing infestations to gain a better understanding of how these weed species would be expected to behave on sites that have not yet been infested. The immediate goal is to find differences among habitats in the potential for future infestation by spotted knapweed or leafy spurge.
This research could ultimately lead to development of site specific strategies for weed management. In such an approach, the combination of weed control methods used for a species such as leafy spurge on a dry, rocky hillside would likely be quite different from those methods used to control spurge along a moist drainage bottom. Identifying habitat differences is a first step. While some of the results found in the current study were expected, others have been quite interesting.
Both spotted knapweed and leafy spurge originated in grasslands of Eurasia. Therefore, it comes as no surprise that the highest infestation levels found in Silver Bow County were in grassland areas. Neither species is very competitive on forested or riparian (near stream) sites in our area. Woodland areas, with open Douglas-fir stands, are intermediate in terms of infestation potential. Neither weed species likes to get their feet (roots) wet for long. This explains their relative absence in consistently wet soils along streams and in other wetlands areas.
Elevation, slope steepness and slope direction (aspect) have a strong influence on the occurrence of both spotted knapweed and leafy spurge in Silver Bow County. The highest infestation levels for spotted knapweed occur below 5,800 feet in elevation while moderate infestations levels were found up to 6,600 feet. For leafy spurge, the highest infestation levels are restricted to elevations below 5,600 feet. South facing slopes (hot and dry) were the most favorable for spotted knapweed while leafy spurge was most prevalent on level to gently sloping areas (deeper soils; deposition areas). Both species appear to be least competitive on north facing slopes.
Overall, the worst leafy spurge infestations were found on very deep well drained (normally dry) soils along drainage corridors. This was especially true where basin wild rye was the primary grass species present. The second most common occurrence was on droughty, shallow soils on volcanic hills such as along portions of I-90 in northwestern Silver Bow County. While leafy spurge fairs poorly on soils formed from decomposed granite, spotted knapweed does especially well on the very deep, coarse textured granite soils common in the Summit Valley.
Those are just a few of many results. At the conclusion of this work, maps will be produced through the Butte-Silver Bow GIS Department showing infestation potential throughout the county. This information will be used to target weed control activities and to support future research on site specific weed control strategies.
As a landowner or tenant, you should be aware of noxious weeds growing on your property. Know how to identify weeds, at least spotted knapweed (below left) and leafy spurge (below right). Scout your property regularly and note their presence if you find them. Pay special attention to where they are growing and begin weed control or encourage the landowner to begin weed control as soon as possible. Remember, early detection and control is by far the most cost effective means to fight noxious weeds. The sooner you get them, the less likely they will be to spread out of control. There is a reason they call them invasive: Weeds infestations will continue to grow if left unchecked and the cost of control grows with them the longer you wait to take action. For more information, please contact the Butte-Silver Bow Weed Control Office at 497-6460 or weeds@bsb.mt.gov.
Thursday, January 4, 2007
The Milltown Dam
Now is the time to go to Bonner to see the Milltown Dam and Reservoir before it is gone. The reservoir is already effectively gone and with construction on the Clark Fork by-pass channels already underway, it won't be long (probably a couple years) before the whole area looks completely different.
Following is a story I wrote that appeared first in The Butte Weekly paying historical respect to the Milltown structure, as well as some forward speculation of what might happen during its removal. Let's be clear: once the dam is gone, the confluence of two of Montana's greatest rivers - The Clark Fork and the Blackfoot -- will be restored and the future of its fisheries will be bright as its been in over 100 years.
Coincidentally, CFWEP in partnership with Missoula's Watershed Education Network (WEN) has just completed the Milltown Education Project. The Milltown project, which was run on the ground by WEN and administered by CFWEP, took schools from Missoula, Bonner and Anaconda on field trips to the dam and reservoir and provided over 100 students with an educational experience at Milltown during its important transformation.
CFWEP is continuing trips to the site, with a date scheduled later this month for 45 Butte High students and a tentative trip for Powell County High students being planned for February.
Read the story and if you still want to learn more, the Missoula County Environmental Health Department (http://www.co.missoula.mt.us/wq/Milltown_Dam/Milltown%20Dam.htm), the Clark Fork River Technical Assistance Committee (www.cfrtac.org) and the Clark Fork Coalition (www.clarkfork.org) websites all have more information. EPA project manager Russ Forba and the Natural Resource Damage Program's Doug Martin are also great contacts and can be reached at their respective offices in Helena.
The Milltown Dam and the 1908 Flood
If the EPA, State of Montana and construction contractor Envirocon get their ways – with a little cooperation from Mother Nature – the century-old Milltown Dam will be removed from the Clark Fork River sometime in 2008.
The Milltown, as Norman McLean would say, is located “at the junction of great trout rivers” (the Blackfoot and Clark Fork) just 7 miles upstream of Missoula near the burg of Bonner. The structure stands as the downstream extent of the nation’s largest contiguous complex of federal Superfund sites, beginning over 100 miles upstream in Butte.
Since the dam was completed in December 1907, it has been the holding stop for all of the contaminated sediments flowing from the Anaconda Company’s mega-mining operations in Butte and Anaconda. This amounts to nearly 7 million cubic yards of contaminated sediments (note: 1 cubic yard = 1 pick-up truck load). Roughly a third of this total – over 2 million yards of the most contaminated sediments – will be removed and sent on a train back upstream to the historic waste impoundment known as the Opportunity Ponds.
Also to be dumped at the Opportunity site will be over 4 million cubic yards of tailings scraped from the floodplain of Silver Bow Creek and anything else nasty that’s removed from the 800-plus acres designated for remediation in the stretch of the upper Clark Fork River between Warm Springs and Garrison.
That’s a lot of contamination. But it’s nothing to the Opportunity Ponds.
The Ponds served as the waste disposal unit during the majority of life of the 585-foot Washoe Smelter in Anaconda. In fact, they aren’t “ponds” anymore, but more accurately a 10-square mile area of blighted desert. To be clear, the volume of wastes being dumped in Opportunity from the various Superfund cleanups can be compared to adding an additional tablespoon of waste to a 5-gallon bucket full. It’s just not that big of a deal – not until it comes time to clean up the Opportunity Ponds.
So let’s switch our focus back downstream to Bonner. In 2003 with then-governor Judy Martz’s stamp of approval, it was decided in the EPA’s Record of Decision to remove the Milltown Dam and a bunch of its contaminated sediments.
Why?
The reasons are many and they’re good ones:
· The dam and its sediments create a groundwater contamination plume of arsenic in the town of Bonner;
· The dam is old and unstable and it blocks the passage of native fish to spawning tributaries in both the Blackfoot and Upper Clark Fork river drainages;
· Fixing the dam properly would cost nearly as much as tearing it out and contaminated sediments wouldn’t be removed to the full extent needed.
· The dam, even in optimum condition, doesn’t generate a significant amount of electricity to justify its existence.
However, this wasn’t always the case. Let it be known that when the Milltown Dam is removed, so will be one of the last standing significant remnants of Butte’s mining history in the basin.
Q. Who do you suppose was responsible for building the Milltown Dam?
A. William A. Clark.
Q. And why do you think he built it?
A. To keep the copper coming out of the ground in Butte.
This was indirectly done by supplying electricity to his lumber mills in Bonner and Missoula (one, good producing underground mine in Butte went through a trainload of timber every week), which also indirectly electrified and helped grow The Garden City in its early days. The Milltown Dam – one of the first major river dams constructed in the Columbia drainage – also marked the birth of the Montana Power Company. Furthermore, Marcus Daly built the first dam in the Upper Clark Fork basin on the Blackfoot just upstream from Bonner about 20 years before Milltown. Coincidentally, Daly’s dam, built to slow down floating logs so they could be retrieved by his own lumber mill, was torn out last fall in preparation for the Milltown’s removal; Bob Gannon removed the Montana Power Company in 2001 in preparation for his own mysterious disappearance.
Built using the standard “timber crib” technology of the day, the Milltown was an engineering stalwart, garnering lofty boasts from its chief financier, Mr. Clark just after its completion. Clark was quoted in the Daily Missoulian to the effect that the Milltown Dam was solid as a rock and would stand through thick and thin, forever more.
Damned if Mother Nature wasn’t listening and just so happened to be in the mood for a fight.
Just a few months after the construction of Milltown Dam was completed, the Clark Fork witnessed the largest flood its pale-faced inhabitants had ever seen. That spring of 1908 the river gorged to 46,000 cubic feet per second (cfs), carrying away near everything in its widened path (Note: the USGS stream gauge below the dam currently reads ~1,700 cfs or roughly four percent of the 1908 flood). Trees, bridges, fences, animals, pert near anything in the flood’s way that wasn’t nailed down and nailed down good. And there were also tailings. Lots and lots of tailings, the result of decades of dumping from mines, smelters and concentrators of The Richest Hill on Earth. It’s fair (and accurate) to say that the majority of contaminants now requiring cleanup in the Silver Bow Creek and upper Clark Fork’s floodplains were deposited in this one storm event.
One big flood + the improperly disposed wastes of the World’s largest mining camp = 120 miles of intense river damage.
As for Mr. Clark’s timber-crib dam, sturdy as it may have seemed to men, it didn’t stand a chance against a taunted and scorned Mother Nature (see photo). The massive flows topped the dam and the river began filling the powerhouse at an alarming rate. With standing water inside the dam control house reaching four feet, something had to be done quickly. Being a mining magnate has its benefits in dire times such as these.
Clark summoned a team of Butte’s underground miners – contracted as explosive experts in this case – to hurry downstream to the rescue. In order to relieve the dooming pressure on the dam and save Clark’s flooding powerhouse and the sole generation source of the infant Montana Power Company, the miners carefully and strategically blasted the south side of the dam to smithereens.
The river temporarily and partially ran free, saving the Milltown structures. Crews and horses spent the rest of the year and into 1909 reconstructing the dismantled dam; less intensive repair efforts were required standard from flood damages until MPC finally applied a concrete veneer over the timber frame in the early 1980s.
Shortly after the dam was veneered, arsenic was detected in the domestic wells of several Bonner/Milltown residents. Ever since science has been slowly but surely been leading policy makers toward the ultimate decision in 2004 to take out the state’s largest toxic sediment trap, thereby saving one town’s drinking water and paving the way to restore the confluence of two of Montana’s greatest rivers.
The estimated clean-up price tag: $111.6 million, which is the projected cost to remove the dam and powerhouse and 2.2 million cubic yards of the nastiest sediments to be sent to Opportunity; and the rebuilding/restoration efforts of putting the Clark Fork and the Blackfoot back into their new, man-made “natural” stream beds. This cost was estimated using several assumptions, the largest one being that Mother Nature will cooperate.
The devastation that followed the wake of the 1908 flood has not been witnessed since on the Clark Fork or any other river in southwest Montana for that matter. To most of us we call that type of storm “the big one.” Hydrologists have a slightly more scientific term: the 100-year flood.
By a non-hydrology definition, the 100-year flood is a flood which on the average will be equaled or exceeded once every 100 years. More accurately, it should be defined as the “1% flood,” because it has a 1% chance of occurring in any given year.
It doesn’t take a mathematician to figure out that right about the time the dam is being removed it will be statistically right about time for us to expect the upper Clark Fork to get its next big flood. What would happen if Mother Nature decided to strike her wrath twice in the same place?
In regards to stream restoration and general land reclamation projects, if She decides it’s time for a 100-year flood in 2008, the estimated cost of completing the Milltown dam removal and restoration can reasonably double. And that’s not counting the additional costs of damage to the downstream Clark Fork and any equipment that might get swept away.
Reclamation/restoration projects need time to stabilize before they can be expected to handle a storm – any storm. Vegetation needs to mature and kinks need to be worked out. If one were to ask an expert how long he/she would reasonably guess this time would be to achieve stability in order for the project to survive the impacts of a 100-year flood the answers would range no less than five years to upwards of 20.
In short, we need to go ahead with the work as planned and hope for the best in terms of Mother Nature’s cooperation. Though in hindsight, we shouldn’t taunt her with any promises of invincibility. After all, the Clark Fork belongs to her and it’s up to her what fate she has in store. At least this century around we’re trying to expedite her work rather than impede it.
Following is a story I wrote that appeared first in The Butte Weekly paying historical respect to the Milltown structure, as well as some forward speculation of what might happen during its removal. Let's be clear: once the dam is gone, the confluence of two of Montana's greatest rivers - The Clark Fork and the Blackfoot -- will be restored and the future of its fisheries will be bright as its been in over 100 years.
Coincidentally, CFWEP in partnership with Missoula's Watershed Education Network (WEN) has just completed the Milltown Education Project. The Milltown project, which was run on the ground by WEN and administered by CFWEP, took schools from Missoula, Bonner and Anaconda on field trips to the dam and reservoir and provided over 100 students with an educational experience at Milltown during its important transformation.
CFWEP is continuing trips to the site, with a date scheduled later this month for 45 Butte High students and a tentative trip for Powell County High students being planned for February.
Read the story and if you still want to learn more, the Missoula County Environmental Health Department (http://www.co.missoula.mt.us/wq/Milltown_Dam/Milltown%20Dam.htm), the Clark Fork River Technical Assistance Committee (www.cfrtac.org) and the Clark Fork Coalition (www.clarkfork.org) websites all have more information. EPA project manager Russ Forba and the Natural Resource Damage Program's Doug Martin are also great contacts and can be reached at their respective offices in Helena.
The Milltown Dam and the 1908 Flood
If the EPA, State of Montana and construction contractor Envirocon get their ways – with a little cooperation from Mother Nature – the century-old Milltown Dam will be removed from the Clark Fork River sometime in 2008.
The Milltown, as Norman McLean would say, is located “at the junction of great trout rivers” (the Blackfoot and Clark Fork) just 7 miles upstream of Missoula near the burg of Bonner. The structure stands as the downstream extent of the nation’s largest contiguous complex of federal Superfund sites, beginning over 100 miles upstream in Butte.
Since the dam was completed in December 1907, it has been the holding stop for all of the contaminated sediments flowing from the Anaconda Company’s mega-mining operations in Butte and Anaconda. This amounts to nearly 7 million cubic yards of contaminated sediments (note: 1 cubic yard = 1 pick-up truck load). Roughly a third of this total – over 2 million yards of the most contaminated sediments – will be removed and sent on a train back upstream to the historic waste impoundment known as the Opportunity Ponds.
Also to be dumped at the Opportunity site will be over 4 million cubic yards of tailings scraped from the floodplain of Silver Bow Creek and anything else nasty that’s removed from the 800-plus acres designated for remediation in the stretch of the upper Clark Fork River between Warm Springs and Garrison.
That’s a lot of contamination. But it’s nothing to the Opportunity Ponds.
The Ponds served as the waste disposal unit during the majority of life of the 585-foot Washoe Smelter in Anaconda. In fact, they aren’t “ponds” anymore, but more accurately a 10-square mile area of blighted desert. To be clear, the volume of wastes being dumped in Opportunity from the various Superfund cleanups can be compared to adding an additional tablespoon of waste to a 5-gallon bucket full. It’s just not that big of a deal – not until it comes time to clean up the Opportunity Ponds.
So let’s switch our focus back downstream to Bonner. In 2003 with then-governor Judy Martz’s stamp of approval, it was decided in the EPA’s Record of Decision to remove the Milltown Dam and a bunch of its contaminated sediments.
Why?
The reasons are many and they’re good ones:
· The dam and its sediments create a groundwater contamination plume of arsenic in the town of Bonner;
· The dam is old and unstable and it blocks the passage of native fish to spawning tributaries in both the Blackfoot and Upper Clark Fork river drainages;
· Fixing the dam properly would cost nearly as much as tearing it out and contaminated sediments wouldn’t be removed to the full extent needed.
· The dam, even in optimum condition, doesn’t generate a significant amount of electricity to justify its existence.
However, this wasn’t always the case. Let it be known that when the Milltown Dam is removed, so will be one of the last standing significant remnants of Butte’s mining history in the basin.
Q. Who do you suppose was responsible for building the Milltown Dam?
A. William A. Clark.
Q. And why do you think he built it?
A. To keep the copper coming out of the ground in Butte.
This was indirectly done by supplying electricity to his lumber mills in Bonner and Missoula (one, good producing underground mine in Butte went through a trainload of timber every week), which also indirectly electrified and helped grow The Garden City in its early days. The Milltown Dam – one of the first major river dams constructed in the Columbia drainage – also marked the birth of the Montana Power Company. Furthermore, Marcus Daly built the first dam in the Upper Clark Fork basin on the Blackfoot just upstream from Bonner about 20 years before Milltown. Coincidentally, Daly’s dam, built to slow down floating logs so they could be retrieved by his own lumber mill, was torn out last fall in preparation for the Milltown’s removal; Bob Gannon removed the Montana Power Company in 2001 in preparation for his own mysterious disappearance.
Built using the standard “timber crib” technology of the day, the Milltown was an engineering stalwart, garnering lofty boasts from its chief financier, Mr. Clark just after its completion. Clark was quoted in the Daily Missoulian to the effect that the Milltown Dam was solid as a rock and would stand through thick and thin, forever more.
Damned if Mother Nature wasn’t listening and just so happened to be in the mood for a fight.
Just a few months after the construction of Milltown Dam was completed, the Clark Fork witnessed the largest flood its pale-faced inhabitants had ever seen. That spring of 1908 the river gorged to 46,000 cubic feet per second (cfs), carrying away near everything in its widened path (Note: the USGS stream gauge below the dam currently reads ~1,700 cfs or roughly four percent of the 1908 flood). Trees, bridges, fences, animals, pert near anything in the flood’s way that wasn’t nailed down and nailed down good. And there were also tailings. Lots and lots of tailings, the result of decades of dumping from mines, smelters and concentrators of The Richest Hill on Earth. It’s fair (and accurate) to say that the majority of contaminants now requiring cleanup in the Silver Bow Creek and upper Clark Fork’s floodplains were deposited in this one storm event.
One big flood + the improperly disposed wastes of the World’s largest mining camp = 120 miles of intense river damage.
As for Mr. Clark’s timber-crib dam, sturdy as it may have seemed to men, it didn’t stand a chance against a taunted and scorned Mother Nature (see photo). The massive flows topped the dam and the river began filling the powerhouse at an alarming rate. With standing water inside the dam control house reaching four feet, something had to be done quickly. Being a mining magnate has its benefits in dire times such as these.
Clark summoned a team of Butte’s underground miners – contracted as explosive experts in this case – to hurry downstream to the rescue. In order to relieve the dooming pressure on the dam and save Clark’s flooding powerhouse and the sole generation source of the infant Montana Power Company, the miners carefully and strategically blasted the south side of the dam to smithereens.
The river temporarily and partially ran free, saving the Milltown structures. Crews and horses spent the rest of the year and into 1909 reconstructing the dismantled dam; less intensive repair efforts were required standard from flood damages until MPC finally applied a concrete veneer over the timber frame in the early 1980s.
Shortly after the dam was veneered, arsenic was detected in the domestic wells of several Bonner/Milltown residents. Ever since science has been slowly but surely been leading policy makers toward the ultimate decision in 2004 to take out the state’s largest toxic sediment trap, thereby saving one town’s drinking water and paving the way to restore the confluence of two of Montana’s greatest rivers.
The estimated clean-up price tag: $111.6 million, which is the projected cost to remove the dam and powerhouse and 2.2 million cubic yards of the nastiest sediments to be sent to Opportunity; and the rebuilding/restoration efforts of putting the Clark Fork and the Blackfoot back into their new, man-made “natural” stream beds. This cost was estimated using several assumptions, the largest one being that Mother Nature will cooperate.
The devastation that followed the wake of the 1908 flood has not been witnessed since on the Clark Fork or any other river in southwest Montana for that matter. To most of us we call that type of storm “the big one.” Hydrologists have a slightly more scientific term: the 100-year flood.
By a non-hydrology definition, the 100-year flood is a flood which on the average will be equaled or exceeded once every 100 years. More accurately, it should be defined as the “1% flood,” because it has a 1% chance of occurring in any given year.
It doesn’t take a mathematician to figure out that right about the time the dam is being removed it will be statistically right about time for us to expect the upper Clark Fork to get its next big flood. What would happen if Mother Nature decided to strike her wrath twice in the same place?
In regards to stream restoration and general land reclamation projects, if She decides it’s time for a 100-year flood in 2008, the estimated cost of completing the Milltown dam removal and restoration can reasonably double. And that’s not counting the additional costs of damage to the downstream Clark Fork and any equipment that might get swept away.
Reclamation/restoration projects need time to stabilize before they can be expected to handle a storm – any storm. Vegetation needs to mature and kinks need to be worked out. If one were to ask an expert how long he/she would reasonably guess this time would be to achieve stability in order for the project to survive the impacts of a 100-year flood the answers would range no less than five years to upwards of 20.
In short, we need to go ahead with the work as planned and hope for the best in terms of Mother Nature’s cooperation. Though in hindsight, we shouldn’t taunt her with any promises of invincibility. After all, the Clark Fork belongs to her and it’s up to her what fate she has in store. At least this century around we’re trying to expedite her work rather than impede it.
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