Rise and Fall of the Napanee River

RISE AND FALL OF THE NAPANEE RIVER
 August 16 & August 18

It was in 2003 when I first met the late Dr. Mac Smith of Napanee. I cannot recall why he wanted to see me, but during the course of our conversation, he mentioned his interest in the Napanee River and the history of the town itself. Since I was interested in conducting a guided interpretive evening hike the following year along the boardwalk that parallels the river from Springside Park to the Centre Street Bridge, I asked him if he’d be interested in co-leading a hike there in 2004. He was more than happy to contribute some information.

Mac arrived that evening, armed to the teeth with photos and a report that he had written on the mysterious “tides” of the Napanee River. On a hike that routinely takes only 20 minutes, Mac, at the age of 79, kept the 20 people on the hike in stitches for 90 minutes as he recalled stories about Napanee, his grandfather (he operated the former Centre Street swing bridge) interspersed with his own take on the well known tides of the Napanee River. It was not unlike Mac to have this zest for adventure, albeit just an interpretive walk with 20 people. The well known Napanee veterinarian, some 50 years earlier travelled. 111 miles on one water ski back and forth on the Napanee River, setting a Canadian record during his almost 5-hour stint. He was a man of adventure, with an insatiable curiosity about the world around him, and the reasons for things being as they were.

Although Mac had heard about these mysterious tides in the Napanee River from local residents, he never appreciated the significance of it, until he observed them himself, and began compiling notes and graphs a few years ago in an effort to document this strange phenomenon. In that first year, he noted one spot along the boardwalk where he observed hundreds of rock and stones in the riverbed, uncovered by water, but yet very wet. Then, he noticed the water starting to rise, until all the stones were covered once again by water. His observations revealed that the river rose between six and 16 inches, and did so with clockwork, peaking every two to two-and-a quarter hours.

Twenty-seven days of observing confirmed that something very predictable was happening in the river, resembling a tide, but he knew that tides simply don’t occur naturally in rivers. He explained that ocean tides are caused by three gravitational forces – the earth, the sun and the moon, peaking twice every 25 hours, the time of the solar lunar day.

“You might think,” commented Mac in a feature in the Napanee Beaver in 2003, “that a strong westerly wind would blow the Bay of Quinte water up the Napanee River and hold it there. Not so. A strong easterly wind should blow the water out of the river and hold it out. Not so. The river tides pay no attention to wind direction, velocity or lack of wind.”

Napanee residents are quite accustomed to seeing winter ice or driftwood floating down the river, then returning upstream a couple hours later, the returning current so strong that it actually forces the navigational buoys upriver with the tide. Mac remembers as a youngster, sailing out of the river with his grandfather Mills on a 44-foot gaff-rigged sloop he had built. They left Napanee with the outgoing tide and made good headway, slowed somewhat on the incoming tide, and cleared the river mouth on the second outgoing tide. An Internet reference dates back even further to the late 1800s when it mentions a ship going aground, “then came a little ‘tide’ the next morning and floated her off.”

So, what is the reason for this strange phenomenon? Apparently, prolonged winds across Lake Ontario from the southwest predominantly, push the lake water to the north shore. When the wind abates, the water surges back to where it came from, in a fixed period of time, very close to 2.1 hours for a one way slosh or surge between Rochester and the Bay of Quinte, a distance of 110 km. The amount of time it takes to traverse the lake is as regular and unfailing as a clock’s pendulum, says Dr. Smith’s report. The surge repeats itself again and again and the sloshing of the water back and forth is called the “seiche” effect and can go on for several days. The important driving function causing the tidal effect on the Napanee River is the wind and the sloshing of the lake together with the river’s willingness to resonate with the lake. They reinforce one another. The tidal flow up the 10 km stretch of the Napanee River requires about one hour and six minutes, peaks, then must return requiring the same length of time, which perfectly coincides with the 2.1 hour seich of Lake Ontario. If the river was any shorter or longer, Mac explained, it wouldn’t work. It’s a case of many factors working in perfect harmony to create was is in effect, a regular tide in the Napanee River.

Napanee is indeed fortunate to have what is nothing less than a tourist attraction, for this phenomenon occurs in only one other river in the entire world. And we have the late Dr. Mac Smith to thank for his persistence in finding the answers, and for providing me with copies of his studies so I am better able to interpret this phenomenon on my interpretive hikes along the river. Dr. Smith passed away this year on April 5th.