Cyanotoxins in the North Santiam Watershed

Cyanobateria are one of the largest and most important bacteria on Earth.  There was no life on land until the Cyanobacteria began releasing oxygen billions of years ago.  Cyanobacteria are found in most all fresh and saltwater environments around the world.

For the past couple of weeks, the City of Salem (Oregon) has issued warnings about potential health issues related to their drinking water.  The source of the problem is a Harmful Algal Bloom that is generating Cyanotoxins (Microsystins and Cylindrospermopsin) that causes a variety of problems for fish, wildlife, pets and humans if ingested. The cyanotoxins are created when Cyanobateria (Blue-Green Algae) reproduce rapidly (due to a variety of factors), create a “Bloom”, then die off, leaving the toxins as they decompose.

Salem, and many cities in the North Santiam Watershed, get their drinking water from the North Santiam River.  The North Santiam is impounded by two Army Corp of Engineer dams (Detroit and Big Cliff) approximately 60 east of Salem.  Detroit Reservoir (behind the dams), being a large body of water, contains Cyanobacteria (obviously).  However, in recent years, there has been an increase in the number, size and duration of the “blooms” and the resulting cyanotoxins levels have reached concerning levels.  For the first time since testing began, the toxins showed up in Salem’s municipal water distribution system. You can read more about that at the Statesman Journal newspaper website.

As a North Santiam Resident, Fly Fishing Guide, River Steward and Watershed Council member, I’m more interested in the cause, rather than the effect (impacts).  Why is it happening, what are the contributing factors, how do we stop it (or at least limit it)?  So far, I’ve stumbled across a few things that are potentially contributing to the increase in Harmful Algal Blooms:

  • Climate Change (Temperature Variance, Rain Cycles)
  • High levels of Nitrogen and Phosphorus
  • Excess Nutrients from runoff and sediment
  • PH level variations
  • Light Levels and Stratification
  • Die off of other bacteria and predators of Cyanobateria that help keep it in balance
  • Natural Adaptation (evolution?) of the Cyanobateria itself

Since I don’t wish to be drawn into the labyrinth of the Climate Change debate, I’ll just let that be for now.  However, that doesn’t mean I won’t point my finger at the other Human Impacts that are potentially part of the problem. Some of the more common blooms around the US have been near big cities (Great Lakes), coastal communities (red tides/shellfish toxicity) and in the heartland (agriculture runoff from pesticides and herbicides).

First, let’s talk about where the blooms are occurring – in Detroit Reservoir – a man made body of water (not a “Lake” as it is often referred to).  Prior to the 1950’s, the North Santiam River flowed from the headwaters in the Cascades to it’s mouth at the Willamette River unimpeded.  Detroit and Big Cliff Dams put an end to that free flow (and blocked fish passage to 60% +/- of the Spring Chinook and Winter Steelhead spawning areas in the watershed).  The dams were erected to control high flows from spring rain and snow melt each year that flooded a good portion of the lower basin on a regular basis. That was a good idea, other than the lack of fish passage.

To get a little more specific, within the reservoir, the large blooms are occurring in the Heater Arm, Kinney Creek Area and near the Dam itself – all of which are on the western half of the reservoir or “downstream”.  This makes some logical sense because that’s where things like sediment and runoff would collect and stagnate, and where nutrients would be trapped and settle.

Something different about these blooms compared to the more publicized blooms around the country is that there aren’t any large cities upstream.  Sure, the towns of Detroit and Idanha are upstream and have known sewage treatment issues, but the population of those communities is very small (less than 500 full time residents combined).  There are numerous campgrounds in the areas upstream.

The reservoir is not subjected to the churning of tides that stir things up and create coastal blooms. There is little to no farming in the area upstream and certainly nothing on a large scale.  Most all the land upstream of dams is National Forest, so logging is very limited nowdays (compared to State and Private land in Oregon). There are no factories producing industrial waste, no large mines in operation, etc. The only thing remotely close to “industry” is the fish hatchery at Marion Forks another 15 miles upstream.

Could this simply be a combination of “all of the above”? :

  • Clear cut logging (and subsequent herbicide use) are known major contributors to sediment and nutrient loading in watersheds (including nitrogen and phosphorus).  Although this has been greatly curtailed in National Forest Land, a Google Earth view of the area indicates a lot of recent (last 20 years) logging activity in the Cumley, Kinney and Box Canyon Creek drainage’s (where the blooms occur).
  • Detroit and Idanha sewage from aged/inadequate septic septic systems leaching into the reservoir from upstream
  • Campground sewage, recreational use on the reservoir
  • Marion Forks Hatchery effluent – fish and fish food waste, chemical disease treatments, etc.
  • Leaching from abandoned / inactive mines
  • Fluctuations in reservoir levels (draw down in fall, retention in spring) churning up sediment every year, changing light and temperature stratification.

Alone, each bullet point seems minor, but added together and maybe there’s something to it.

With the current political atmosphere, I doubt there will be much in the way of scientific study on the matter.  With the  reduced funding of the EPA, NOAA and other government scientific type entities and the emphasis on reducing regulations, the time and money won’t stretch to our little corner of the country.

A friend of mine claims this is all a big conspiracy.  I’m not sure I buy into that, but I don’t have any doubt that this current issue will be used for political and social gamesmanship for the foreseeable future.

The North Santiam Canyon Joint Wastewater project may get moved up a bit.  Salem (and other communities downstream) may make investments in municipal water treatment facilities to rid the systems of cyanotoxins. Opponents of the USACOE water mixing tower and juvenile fish passage project will likely use this to their advantage as well.  The projects will cost huge amounts of money and ultimately, taxpayers and water consumers will foot the bill. In the end, the water in Salem will be safe to drink again. Once the immediate issue is taken care of, the causes will be ignored. The band-aids will have been applied.  Fish, wildlife and the environmental concerns will fade from our collective memory.

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