I decided to take a drive out to Brockport for a walk
I’d heard the Vegetation Project had been halted there due to inclement weather. Today was a pleasant day with plenty of sunshine, so a great time to take a few photos perhaps.
Trying to find where the last clearing had been done was fairly easy, as I had the RIZZO map on my computer, so I pulled off into the village on Rte 19 north.
The section next to the bridge, marked A036 had nothing going on regarding vegetation removal. Actually, it looked like nothing had been going on for a hundred years. Considering this was ‘downtown Brockport’ the embankments were a disaster. Huge tree stumps, 4 feet in diameter, were left on the crest of the dam, within a foot or so of the towpath.
They were rotting and pieces of the stump could easily be pulled off. These trees must have been 80-100 feet tall in their day. The roots must have grown into the canal, because roots spread out as wide as the canopy. If the stumps were rotten, it’s a good bet the roots were too, so this would mean there was good potential for ‘piping’ to occur. Water could wick along the rotten root and eventually cause a breach in the embankment.
There were at least eight stumps in a row, each about 20 feet apart. The slope there was at 70 degrees, one of the steepest I’ve ever seen, and the scrub there was impenetrable. No one has inspected this in twenty years.
There are many buildings in the potential flood zone. The Phreatic Line must be compromised here, as the upside of the towpath is very steep rip-rap rock, and the downside (where the vegetation is) is at 70 degrees, so steep one could not walk it, so inspection would be impossible.
So, here we have the following problems.
The Phreatic Line is above the toe of the embankment. This means saturated soil from natural wicking of canal water through the embankment will output above the ground level, so the dry soil above this line could slide, causing a breach.
Old roots from large trees have created thin channels through the embankment. A piping effect through them is highly probable.
No inspections have been done, and none are possible without total removal of stumps, and scrub.
High population area with high potential loss of life and property damage.
No toe drainage system in place.
Slopes need to be cleared of all stumps, and a qualified dam engineer supervise infilling, then bank slopes infilled and re-graded to provide a gentle slope of about 3o% instead of 70%. A toe drain needs to be installed.
Going further west along the south bank, I came across the area designated A031 on the RIZZO map.
The photo above shows the trail embankment with trees removed
Obviously, this work was incomplete, but it was quite noticeable that only the trees on the slopes had been removed, and there were plenty left at ground level, so the overall look of the embankments had hardly been altered drastically...