Wednesday, August 5, 2015

Up the Assabet Without a Paddle

If the question is, "If it's possible to kayak down the Assabet River through the middle of Maynard, i.e., Ben Smith Dam to Waltham Street Bridge, a bit over one mile, is it possible to walk up the same stretch of river?" then the answer is "Yes, but..."

David Mark, Assabet River, 7/26/15
Beginning a half-mile river walk
To test this, I stepped into the river by the footbridge behind Gruber Bros. Furniture and walked upstream half a mile to the Mill Street Bridge. Elapsed time was one hour. I had intended to continue to the Ben Smith Dam (another quarter mile), but was exhausted, hence the decision to step out early.

The water was clear, with little in the way of surface-growing algae and duckweed that have plagued the river in past years. There were no off-putting odors. What with the steep, rocky riverbanks, there was little in the way of shoreline water plants, such as cattails.   

There is a beaver lodge on the north bank of this section of the river. Dimensions are about twelve feet across and six feet tall, topped and surrounded with lushly growing plants.  Low water on the day of my walk meant that the two entrances were not under water. I startled a young beaver that was munching plants on the riverbank. It did the tail slap and swam past me underwater, eight feet from where I was standing. Other nature sightings included a great blue heron, fish, frogs, crayfish, mussels... Not-so-nature sightings included bottles and pottery shards, a propane tank and an engine block. No automobile tires. 

Safety, you ask? I was wearing water shoes - a rubber-sole, shoe/sandal hybrid - and using two ski poles for balance. Every step, I had both poles in contact with the river bottom. The poles also helped me check depth as I moved forward. This was useful, as while depth at the downstream gauge was only 1.5 feet, there were several passages two to three feet deep and one section I skirted that was more than four feet deep. Much of the bottom was loose rocks from baseball to softball size and larger. Other stretches were a mix of sand and gravel, some bare and others covered by aquatic plants. There was very little of silt/mud bottom because small particles are trapped behind the upstream dam.

How bad was it? Photo of tires, underneath the Walnut Street Bridge (1974)
Ralph Sheridan, courtesy Maynard Historical Society 
Guidelines for whitewater rafting, canoeing and kayaking strongly caution against trying to stand up in fast-moving water. The risk is that a person can get a foot entrapped in rocks or sunken tree branches, be pushed over by the moving water, and be unable to self-rescue. My adventure in the Assabet was at a time the water level and flow at the U.S. Geological Service gauge was at the lowest it has been all summer: 1.5 feet deep and 36 cubic feet per second (cfs). No part of the river would have qualified as Class I rapids. Fast-moving water was no more than half a foot deep. Deeper at the gauge would also mean faster - six inches more would mean flow at 100 cfs. At 2.75 feet (the lowest considered boatable through town) the flow rate would be 300 cfs, with sections of Class II rapids.

Approaching Mill Street Bridge. Note large rocks and
tree trunk downstream of the middle channel (July 2015)
The river's flow through town is actively managed, and has been mismanaged in the past. Old record show that at times during summer months the volume of water would decrease precipitously for a few days, getting to as low as two cfs - a trickle - and then revert to what it had been before. What was happening was that all water was being diverted to top up the mill pond at the expense of the river. Currently, restrictions are in place so that whenever river volume drops below 39 cfs, no water can be channeled to the pond.  

The Commonwealth of Massachusetts and towns in the Assabet River watershed aspire to getting the river to Class B, defined as clean enough for swimming. Right now most of the river's status is Class C, which allows for fishing and fish consumption, diverse aquatic life, maintenance of biological integrity, use for agriculture irrigation and secondary recreation, the last defined as wading, boating, and other uses involving human body contact with water where such activities take place in an infrequent, unorganized, or incidental manner.

Engine block on rocky shore. Begs the
question: "How did that get there?"
When I first had the idea for this adventure, friends suggested I inform the police of my intentions, the concern being that a homeowner along the river, or a passer-by on a bridge might call 911 to report a person in the river. I took their advice. I also discussed my plan with the Conservation Commission. I did have a conversation with one waterfront owner, but he was more interested in telling me of his efforts to remove trash from the river than what I was up to.

Ten hot, dry days after my river walk, flow had dropped to under 30 cfs. Then, the afternoon of August 4th, severe thunderstorms with wind, rain and hail, swept in from the west. Rainfall was over an inch in less than half an hour. In the same time period the river rose more than half a foot and flow tripled.

Extreme low water at the Ben Smith Dam (July 2010)
Sofferman has posted several videos on YouTube of kayaking the Assabet through the center of Maynard under various conditions. A seven minute clip posted as  is from February 2014, with the river still sporting lots of ice and snow.

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