The mouth of the big, muddy Kenai River/Craig Medred photo
Heavy with sand and silt, Alaska’s Copper River resembles nothing so much as a slurry pipeline as it carries to sea the outwash of dozens of glaciers in the Wrangell/St. Elias Mountains of Eastern Alaska.
So dirty is the water, the human eye cannot penetrate its cloudy surface. So large is the sediment load, it can be heard grinding against the rock walls of Wood Canyon as the muddy water roars toward the seas.
Two-hundred miles to the west and south, the Kenai River flows gray-green out of the mountains of the same name into an estuary where it begins to dump its sediment load, leaving thick deposits of mud along the riverbanks in places.
When the dirt in the water is measured in “nephelometric turbidity units” or what are usually just called NTUs, the dirty Copper registers 574 on average, but sometimes climbs to a maximum of 678, according to a report from University of California, Davis.
At Kenai River mile 11.5, where the fast-flowing waters of the mountain river sometimes flow out to sea and where the big, rising tides of Cook Inlet sometimes cause the river to flow back toward the mountains from which it came, the Kenai hits a maximum of about 55 NTUs, according to the Alaska Department of Environmental Conservation (DEC).
At its worst, the Kenai is more than 10 times cleaner than the Copper – the river famous for its world-famous Copper River king salmon. They are considered such a valuable, wild, unspoiled, fresh-from-Alaska prize that they were fetching prices of more than $55 per pound earlier this year.
The Kenai, too, is famous for its king and sockeye salmon. But other than that, the two rivers are very different.
The state of Alaska has now declared the water in one of them “impaired.”
Guess which?
It’s the Kenai
The DEC has issued a report concluding the lower reaches of the hugely popular glacial river only about 100 miles south of Alaska’s largest city – the river from which came the world-record 97-pound, 4-ounce king (Chinook) salmon, the river that attracts sockeye salmon anglers by the hundreds of thousands every summer, the river after which the entire Kenai Peninsula is named – is unacceptably dirty.
“…The Kenai River is getting a failing grade,” Alaska’s Energy Desk at Alaska Public Media reported last week. “The state is recommending that it be put on a list of polluted waterways.”
A “polluted” Kenai is great click bait. Some readers here, maybe many, are reading this story because of the pollution reference. APM headlined its story “State’s latest water quality report has bad news for popular Kenai River.”
That’s true to the extent the state wants to use the report declare the lower river “impaired,” but what turbidity means in terms of water quality in Alaska is a very, very confusing issue.
“You’ve got to keep it in context,” said Brock Tabor, a DEC water-quality specialist. “There is certainly debate within the scientific community….What is the definition of impaired, and what does that mean?”
There is no fixed level of turbidity at which water quality is considered to be “polluted.” There is only a relative standard, except where there isn’t.
The state’s regulations don’t even hint at what NTU level disinfection might become a problem, but that might be because visibly dirty water – anything above about 5 NTUs – usually undergoes some sort of mechanical treatment before disinfection.
Where murky water is used for drinking, it is most often pretreated via settling ponds, coagulation or flocculation to remove sediments before disinfection. The turbidity is reduced because it makes bacteria in the water harder to kill.
And, of course, nobody wants to wash with, let along drink, water that appears dirty. Tap water in the U.S. is usually below 1 NTU. Water starts to look cloudy at 5 NTU, and at 25 NTU it gets murky.
The Kenai is pretty much always murky, and sometimes it looks worse. Looks matter here. They are at the heart of the turbidity issue on the Kenai.
The pristine north
“This goes back to when AK first developed the regulations,” Tabor said. The intent then was to keep Alaska’s clear waters clear. Clear waters are the most biologically productive. They are where little salmon start growing their way toward becoming big salmon.
Alaska had a bad history of dirty water, too. Dirty water from placer mining in territorial days into the early Statehood years in Alaska was linked to significant losses of fisheries habitat. Miners used water cannons to wash away the banks of some salmon streams in the search for gold. They walked dredges up others, ripping out the gravel as they went and leaving a muddy trail behind.
The results were not good.
“A 25 NTU increase in turbidity in shallow, clear-water systems may potentially reduce stream primary productivity by 13 to 50 percent or more, depending on stream depth and ambient water quality,” state biologist Denby Lloyd reported in a 1986 study. Lloyd was destined to go on to become a future commissioner of the Alaska Department of Fish and Game.
His study posited the appropriate question for the day: “What, then, are acceptable levels of human-induced turbidity in freshwater aquatic habitats that support fish and wildlife?”
His answer was that almost any increase in turbidity would lower fisheries productivity, but his study contained important caveats: “in shallow, clear-water systems…in freshwater habitats that support fish.”
The stretch of the Kenai under discussion as impaired has never been a “shallow, clear-water system,” and as a freshwater habitat for fish it is almost as marginal as the main stem of the Copper. It does not support large numbers of fish.
It is murky water through which salmon pass on their way to and from waters that support salmon.
Whether the water being more murky or less murky makes a difference to young salmon leaving the river or adult salmon returning is a question as to which no one has an answer. So, too, the question of how murky the lower river is naturally.
A two-way river
The DEC decided the lower river is impaired based on the difference in NTUs between a measuring station at river mile 23, just a few miles downstream from the Soldotna bridge, and a measuring station at mile 11.5.
The river bottom at mile 23 “is predominately gravel and cobble. The bank is comprised of poorly sorted cobble and gravel with minor amounts of sand and silt in the interstices,” according to 2008-2010 turbidity monitoring report prepared by the Kenai Watershed Forum.
At mile 11.5, the same report says, the river bed is “moderately sorted gravel overlain with well-sorted, fine-grained sand and silt. The depth of the sand and silt layer varies over the course of the season….A tidal influence is present at RM 11.5 and sites downstream of this location. During high tide the river water becomes backed up, resulting in slower water velocity and raised water levels. Reduced water velocity allows for the deposition of fine-grained silt.”
That silt build up only increases as one goes downstream to Cook Inlet. It is the reason the waters in and around the Kenai City Dock near river mile 1 comprise the dirtiest part of the river. The water is dirty even when the normal swarms of commercial and recreational fishing boats aren’t there to stir it up and make it dirtier.
There is no doubt boats stir up the silt. How much of that dirty water is picked up and pushed to river mile 11.5 on the incoming tides is an unknown.
It’s all about boats
The Watershed study was designed to buttress the argument that sport fishing boats using the lower river in July, when the king salmon fishery is at its peak, stir up the water and increase turbidity. Ricky Gease, the director of the Kenai Sportfishing Association, said that seems to be the heart of the discussion at hand.
Commercial fishermen in Kenai don’t much like to see tourists, be they from Atlanta or Anchorage, on the river catching fish. Commercial fishermen are a powerful interest gorup that would rather see the fish in their nets in the Inlet.
Gease and lots of other anglers see the turbidity study as largely a ploy to try to push people off the river.
The DEC backed studies, the Watershed report admits, were begun to examine the suspected belief “that human activity in the form of motorboat usage was a factor in elevated turbidity levels in the lower river.”
Only the role of boat activity in turbidity wasn’t suspected, it was obvious. Boats make the water slosh around. Sloshing water stirs silt. The water gets a little dirtier. A moose stomping around in the muck would do the same thing.
The question is whether it means anything at a fisheries habitat level or just at a written-rule level.
Cindy Gilder, a DEC staffer working on the issue, couldn’t answer that question, though she did provide a solid defense of the department’s conclusion that boat use on the river is the main factor affecting turbidity.
“When you look at the cycle of the tides and the boat traffic,” she said, “they don’t correlate.”
Whether there is any correlation with the heights of the tide and turbidity, or the volume of boat traffic downstream from mile 11.5 on the days of the worst turbidity upstream isn’t examined in the report, however.
But like some of the rest of the issues being discussed, it might not matter. The big question at the end of the day is a simple, philosophical one:
If water gets dirtier for a few days or weeks every summer and the salmon don’t notice, does it matter?
DEC is holding a public hearing on the plan in Anchorage on Jan. 4.
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Categories: News
So, i think we all understand the need to keep all rivers “clean” to support spawning. However, i find it interesting that with all the pressure to kill fish returning to the kenai, there seems to be no mention of historical run numbers and any correlation to “turbidity below mile 11.5”. I spend a fair amount of time on the kenai and the larger issue is to address the in river escapement of kings vs sockeye. The kenai is famous for it’s world record kings yet we seem to manage the river for sockeye escapement. Years ago the smell on the kenai was of rotting salmon, nobody really knew what the escapement “number” was. We really do not know what that number is today either. One thing however we do know, we can see and smell LESS rotting salmon than we used to, no question.
As I recall Bruce, there has been a push to try to keep rotting salmon away in order to keep bears away. Used to be lots of carcasses left on the banks and sloughs from folks filleting their catch before heading home. It was this behavior that has been discouraged IMO that has contributed to the lack of rotting salmon smell you speak of.
I guess i was not clear about my point, the kenai used to be littered with salmon carcasses, most of them “non-filleted”, ie, the ones that die after spawning. So, i do not think our current “escapement” numbers correlate to the old days and the number of dead fish along the banks. Furthermore, i believe that if Kenai Kings were treated the same way as spotted owls, the entire fishery would have been closed years ago. Instead, the various user groups compete for their “share” (of sockeye) and the giant kings have disappeared.
I get your point now, Bruce.
While I can’t speak to, in general, “old days escapement” on the Kenai I do know that the 89 EXXON spill allowed for a large escapement of sockeyes there. Also, the CI gillnetters got a large EV settlement based on their overall catch numbers for the years immediately preceding 89 that have not recovered since IMO.
This 2003 study made some statements, about what occurred on the Kenai, explaining the drop in sockeye numbers following the large escapement due to EV spill: http://www.evostc.state.ak.us/Store/FinalReports/1996-96258A1-Final.pdf
Todd, I’m not sure why you misrepresented Craig’s comment comparing that portion of the lower Kenai in question, not the entire mainstem Kenai, to the mainstem of the Copper.Here’s what I read,” The stretch of the Kenai under discussion as impaired has never been a “shallow, clear-water system,” and as a freshwater habitat for fish it is almost as marginal as the main stem of the Copper. It does not support large numbers of fish.” Also, good to know that we can’t control natural factors.
As I read this, the only thing that matters between these two rivers is whether/not there are spawning fish using the portion of the lower Kenai. The lower Copper doesn’t have spawning salmon, clearly, but the original sonar on the Kenai was at MP 9 to be sure of counting all king salmon as some felt that spawning did occur upstream of MP 9. This may have changed, due to turbidity, but this is exactly why this study is being done IMO. If some king salmon spawning habitat has been lost, due to boat turbidity, I would think we would want to know this.
Kevin – the entire premise of Craig’s piece was to compare the Kenai to the Copper with regard to production and turbidity, which is absurd. If you have data suggesting otherwise, please share. I realize that this discussion is difficult for your organization, considering your corporate sponsors, but I really do think that all users would be better off if you stop supporting this “it could be good for the river” B.S. and join a reasonable discussion of how to preserve access while minimizing impact.
Clearly a clever maneuver by the administration to reduce harvest by Sport and PU users in the Kenai. Thankfully the current Governor, who is ultimately responsible for decisions by ADF&G and ADEC, will soon be evicted from Juneau and his successor will quickly undo the damage that Walker is bent on wrecking upon the non commercial uses. The vast majority of Chinook spawning occurs above mile 11.5. The river purges itself regularly from 11.5 down, and is magnitudes clearer than the Copper and the Susitna rivers and which no one claims they have turbidity issues affecting return of Salmon. Turbidity issues in the Kenai. I don’t think so. Political issues? Absolutely!
A good case for getting more Chinook in the Kenai and the Susitna is to stop the mismanagement and the one sided regulatory process both of which give preference to the commercial fisheries. And it appears that can only occur with a new Governor committed to complying with Alaska’s Constitution. Soon to happen!
Your statement “The vast majority of Chinook spawning occurs above mile 11.5.” is no doubt correct, AF. Further, nothing in this study is bent on suggesting that this turbidity in the lower Kenai is causing grief for king salmon traveling through it.
What is the intent of this study, IMO, is what has occurred to the spawning habitat (for king salmon) in this part of the Kenai due to this “turbidity.” While these potential spawners are clearly in the minority, if there are any left at this time, it’s still an important issue to look at IMO.
I don’t see this as anything political, just a habitat issue.
Those of us we drive across the Kenai River, often ten times a day, see the changes in turbidity. During break up, and after significant rainfall, the river becomes more turbidity. The lower Killey River is often responsible for large amounts of silt as is the Funny River. In the lower river, tide water is often very turbidity when wind driven waves create turbidity conditions in the inlet that flow into the river on incomming tides. Visibility on the clearest water days in summer and fall rarely exceed one foot. Kenai Lake itself and Skilak Lake are both turbid. This DEC study should be reviewed for accuracy and relevance before any conclusions are drawn.
Besides yourself Jeff, who else should be on the committee studying “accuracy and relevance?”
I remember back in early 90s Wally Hickel, trying to get a highway along the Copper river, got into a jam when DOT workers were caught dumping dirt and debris into the Copper. Folks had a hard time believing a few loader dumpings of dirt would alter turbidity of the Copper but I suspect those loader dumps took place in the tributaries as nobody in their right mind would get near the Copper with a loader, in many places.
At any rate, the end result was the road construction was stopped.
Craig – you forgot to point out that the majority of salmon production in the Copper happens in the upstream tribs, while Kenai King salmon spawn and rear right in the main stem of the river. Totally different river systems and not responsible to compare them across the board.
Todd, Happy New Year, have you spent any time looking at the Klutina River? The Klutina is a large tributary to the Copper that supports maybe 20% of the king production in the system, The Klutina runs turbid a good share of the time. I can think of many other locations across the state where king salmon spawn in waters that are turbid to some degree. I think that Craig’s question pretty much goes tot he heart of the issue.
Kevin – happy New Year to you as well. So do you agree with Craig that “as a freshwater habitat for fish it (the Kenai) is almost as marginal as the main stem of the Copper”? I’m no fisheries scientist, but that seems a stretch to me considering the differences and the number of fish that live, grow, and breed in the Kenai. I have not seen the Klutina, although I don’t doubt that, like many Alaskan streams, it runs turbid a good share of the time. Perhaps it would be a more productive stream if that weren’t the case, but we can’t control natural factors. While there might (and should) be debate within the scientific community over what exactly defines “impaired”, I don’t think there is much debate over the fact that excessive turbidity negatively impacts salmon production, or that intense powerboat use negatively impacts river habitat. The organization you and Mr. Gease represent appear to stand alone in that regard. It’s shocking to me that KRSA’s Executive Director would suggest that the turbidity study is an allocation-based conspiracy between the KWF, the DEC, and commercial fishermen. It’s pretty offensive, and unproductive toward finding solutions to minimize our impact on the resource. I think the heart of the issue is finding constructive solutions to minimize our impact. That’s going to be more difficult if the leading “conservation” organization on the Kenai river is still mulling philosophical “if a tree falls in the woods…” type of questions rather than accepting the scientific data and offering solutions to minimize impact.
Todd: i’m totally lost as to your point. this wasn’t a habitat study. it was a turbidity study. it put some numbers on something that was obvious to everyone who spends time on the Kenai. the lower river gets more or less turbid day to day, sometimes hour to hour, depending on a several factors – boats being but one. the study is flawed science in regard to turbidity because it has no control on the measurement of dirty water for the “upstream” source when that source happens to be “downstream.” it’s the tidal issue. but the big problem is that the study didn’t tell us a thing about what this turbidity has to do with ecological productivity. it could lower productivity; it could have no effect; it could raise productivity. if you’ve got the studies to back up the conclusion that there isn’t “much debate over the fact that excessive turbidity (and you might want to put a number on the “excessive) negatively impacts salmon production” in areas of extremely limited (if any) intertidal spawning by Chinook salmon link them up. i’ve never seen any such study. i’ve also never seen any studies on avian predation in the Kenai. glaucous-winged gulls nest in some number on the Kenai wetlands. they are known predators of salmon smolt. increased turbidity in the river might decrease avian predation. if so, increased predation could be a good thing. personally, good or bad, i think the overall impact on Kenai salmon numbers (natural mortality among salmon is huge) is so small that if i was on a selection panel i’d never approve funding for such a study, but it would be interesting to know what the turbidity actually MEANS on an ecosystem basis. and one never knows quite knows how things like this work until they are studied. i’m really tired of this newfound scientific bias that assumes (something that has a tendency to ‘make an ass out of “u” and “me” as most journalists learn early or should) any human alternation in any environment is bad. bad and good are conclusions. only fools make conclusions in the absence of evidence. the only evidence we have here is that motor boats make the water somewhat dirtier for a relaltively short period of time. we have no damn clue as to the ecological meaning of this and to suggest otherwise is just to make fakery of science. https://www.nwfsc.noaa.gov/assets/26/4687_05222017_132933_CRE-Avian-predation-2012.pdf
Craig – pretty sure that a study of water quality in a Salmon bearing stream is by definition a habitat study. While tidal influence is present at RM 11.5, it is not true that the river flows backward there during a flood tide like it does at the City Dock. While the study lacked a fixed monitoring station below RM 11.5, there were periodic samples taken lower at RM 8.5 (where tidal influence is much greater – the river changes a lot between RM 8.5 and RM 11.5, including the first King Salmon bearing trib at RM10) to determine the natural effects of the tide. In short, I think you are being a little dishonest in your characterization of the Kenai River at Rm 11.5; it is nothing like the inter-tidal area of the lower river, and it’s nothing like the Copper River. You linked the Lloyd paper in your story – which shows a clear link between turbidity and salmon production, and the term “excessive” is clearly defined by the DEC. Do you have any data to support your theory that the intense powerboat that we see on the lower Kenai could be good for river habitat?