There are a lot of rivers, streams and lakes to visit. For casual observers, it’s sometimes hard to tell how natural they are. Last year, I spent some time digging into all the ways that dams along the Saranac River change the flow of water and the life of fish.
But dams change something else, too: dirt.
Dams hold back and can suddenly release dirt, or they change the way water flows and those changes, in turn, change how sand and gravel build up both before and after dams’ spot in the river. Whole books, including the classic textbook Fluvial Processes in Geomorphology, have been written on these changes to dirt accumulation, usually known by the more technical word “sediment.”
This dirt is more than an academic exercise, though, as ongoing problems in the Town of Malone show.
There’s currently a lot of drama over some dirt that has built up in the Salmon River, which flows through Malone. The town is just outside the park, but the drama there is worth paying attention to.
Town officials say an accumulate of dirt in the Salmon River has “besieged” the town with ice jams and floods.
In a moving letter to the Federal Energy Regulatory Commission, which oversees power-generating dams, Town Supervisor Andrea Stewart blames a dam owner for failing to let town officials onto private property to figure out how to control the dirt and, in turn, calm the danger from jams and floods.
“This river is in our town,” Stewart wrote last February. “Our roads are impacted and flooded, our residents and taxpayers are displaced, and our municipal highway departments are stressed by the ice and flooding that occurs, sometimes several times during the winter season.”
Stewart said the flooding also endangers the nearby wastewater treatment plant and, so, could cause an environmental disaster in one of the tributaries of the internationally important St. Lawrence River.
The dams have changed hands over the years but the land in question is now owned by Erie Boulevard Hydropower, an energy arm of a massive Canadian infrastructure company with projects all over the world. The company said it has met with town officials but the officials have sent mixed signals about what they want to do about the dirt.
In a recent letter to federal regulators, Erie said it “objects to the town’s allegation that Erie has caused the sedimentation and further disputes any economic liability to the Town regarding removal of the sedimentation.”
Photo: Anglers on the Salmon River/Almanack archive
Editor’s note: This first appeared in Ry’s “Water Line” newsletter. Click here to sign up.
This is no idle problem and any possible solution is very expensive. In Carmel Valley, California there was a decaying dam which was no longer needed to supply water to the DelMonte Lodge ( they had city water now) and it was an impediment to the spawning steelhead trout. The sediment build up behind the dam could not be released downstream so they had to build coffer dams to divert San Clemente Creek so they could remove the dam itself and the accumulated sediment. Now the creek flows unimpeded to the Carmel River into the Pacific Ocean and the steelhead trout are able to live out their life cycle. But it took years and whole neighborhoods had heavy traffic from massive trucks and dust all over and it cost a lot ! Dams for electricity and irrigation enabled the growth of this country but they have not been well maintained and their failures have been catastrophic. Malone does not have the resources to solve this problem on it’s own.
Dirt is one thing, contaminated sediment is another. Contaminants can concentrated in the soils that accumulate behind a dam— an issue of concern for places like the Imperial Dam, just downstream from the Northway on the Saranac River.
I suspect another overlooked source of dirt is all the sand in the plowed snow that gets (or used to get) dumped into the river(s). When I was a kid growing up, big village/town dump trucks full of plowed snow used to dump it in the Saranac River in and around the village. Now there are huge sandy silt beds above the trestle and below the rapids beyond the Pine Street bridge in town. I don’t know for a scientific fact, just anecdotally from the observation of a kid growing up on the river, but I bet a lot of that sandy silt buildup is from that practice. We used to swim in that river as kids. Now both spots are just a plain mess.
My first reaction to Ry’s article is– What specifically does the town believe is causing their sediment problem? Fluvial sedimentology is a complex process. To evaluate accumulation or erosion of fluvial sediments, in addition to local conditions, one has to consider the many conditions that control these processes in the entire stream basin, not just at a local site. Factors that have to be considered that can affect sediment transport in a fluvial system are 1) changes in land use practices (ex. logging can result in sediment erosion), 2) climate changes (ex. we’re seeing more precipitation and more intense storms during there last several decades), 3) changes in the channels (ex. sediment erosion-control construction projects, dams, pipeline crossings, dredging in the channel, bridge renovations, etc.) which can change the gradient of the channel bed and could alter a knickpoint in the bed channel that will propagate changes in the channel network for long distances stream upstream and downstream and the cause sediment to either accumulate or erode until a new equilibrium is reached in the system. I hope the town evaluates the conditions in the entire river basin as well as what is happening locally that may be contributing to their problem.
My first comment would be do not use the word “dirt” for sediment if you want to be taken seriously. We live in the Adarondack park and the water shed is steep and fast moving. Erosion is a huge problem especially with the heavy rain events we are experiencing these days with a changing climate.
Dams are highly regulated in New York State as to how much and how fast releases can happen.They must also keep a minimum flow even during drought. Any slowing of moving water will drop sediment regardless of if it is a dam or a flat section of stream.
Dredging any body of water in the Adirondacks is nearly impossible with the regulations of so many agencies with competing jurisdictions.
I would recommend working with the county Soil and Water District, DEC, Trout Unlimited, APA and everyone that can help to find where is the sediment coming from, work with volunteers to reduce erosion with Riparian buffers, plantings, stream bed modifications and work with the dam owners and regulatory agencies to find a solution instead of wasting money on law suites and liabilities.