Ascending and descending towboats and Burlington Northern freight trains on the opposite bank provided unsettling sleeping conditions last night. Occasional howling of coyotes and faint sounds of a distant wip-por-will provided long intermissions from the roaring noise of diesel engines, which take center stage on the Mississippi's main channel.
I broke camp at 5:00 a.m. and headed downstream into a heavy fog about an hour later. A short distance down river, a mainline tow with 15 empty barges was parked along the left descending bank apparently waiting for the early morning fog to lift before completing his ascent to the St. Paul Barge Terminal some 40 miles upstream. The fog slowly gave way to a clear cloudless sky with cool winds from the northwest. Bright white clouds from the cooling towers billowed up over Northern States Power Company's Prairie Island Nuclear Generating Plant as I drifted by shortly before 8 a.m. I passed over the turbulent upwelling of the facility's cooling water discharge on the right bank to assess the thermal mpact on the Mississippi River. The effluent temperature was only a few degrees warmer than the receiving stream. The thermal plume tends to hug the Minnesota side of the river channel as it moves downstream to Lock and Dam 3, just three-quarter miles downstream.
The gates to Lock 3 opened for me at 8:05 a.m. and I exited 10 minutes later. In contrast, a typical tow with 15 barges require and hour and a half to lock though due to a need to "break up" the barges into two sections. Then the first set of barges is pulled out of the chamber by a large cable attached to an electric winch. The following set has the tow attached and is powered by the boat's powerful diesel motors. Finally, the two sets of barges are reunited and a series of one-inch diameter steel cables bind the barges into one unit before departing.
At 9:39 a.m., I passed under the Hwy 63 bridge at Red Wing, Minnesota and found two Minnesota Department of Transportation employees measuring the river's flow in a brand new survey boat equipped with an acoustic Doppler current profiler (ADCP) attached to a laptop computer. The ADCP instrument provides a means of measuring the river flow automatically by using the stream's suspended particles to sense current velocity while at the same time measuring the depth. Essentially, the boat is driven slowly across the channel and the ADCP unit with the attached computer integrates the velocity-depth measurements into a discharge measurement and displays resulting velocity cross-section on the laptop's monitor with different colors representing varying current speed. Large schools of fish can occasionally be captured with this sonar equipment and are depicted by large colored blobs in the velocity mosaic. I asked them why they needed to gage the Mississippi River since the U.S. Geological Survey (USGS) and Corps of Engineers provides flow measurements at numerous sites on the river. They informed me they were just testing the equipment and learning how to operate the new technology for work in inland streams where gaging information is unavailable. Based on the size of the boat and its two large outboards, I wondered just what "streams" they plan to float their boat in that is not already monitored by the USGS.
I wished them luck and headed downstream.
I stopped at a small marina south of Red Wing and purchased a frozen Milky Way candy bar at a dockside shop. This also provided an opportunity to stretch my cramped leg muscles. The influx of sugars and the brief walk renewed my strength to begin my descent of Lake Pepin, which lay 2 miles down river.
The northwesterly winds increased as I entered the open expanse of Lake Pepin on the Minnesota side just opposite Bay City, Wisconsin. The 6 to 12 mph tailwinds provided a great assist in my easterly heading down the head end of the lake. At 12:50 p.m., I stopped briefly at the Frontenac beach to sponge a small amount of lake water out of the canoe. This unwanted ballast water was paddle spray that accumulated during my initial 5-mile descent of the 25-mile long lake. Grass-like flakes (colonies) of Aphanizomenon flos aquae swirled in the water near the beach. This species of blue-green algae can form massive blooms in the lake during summer low flow conditions and was causative agent in a large fish kill on the eastern shore near Maiden Rock in August of 1988. The concentration of this alga was low today and was overwhelmed by other smaller planktonic diatoms and other seston, which departed a yellow-brown color to Frontenac's bay.
Just above Lake City, Minnesota, I met Rob Burdis and his technician Denise, Minnesota Department of Natural Resources employees, who were out collecting water samples for the Metropolitan Council and the Federal Long Term Resource Monitoring Program. Rob initially didn't recognize me as a result of my 11-day-old beard and funny wide-brimmed hat. He provided an informative update on Pepin's recent water quality conditions and other friendly exchanges. We took each other's picture then I headed on down the busy lake trying to avoid the many fishing boats, water skiers, personal water craft, recreational boaters and sail boaters that were using the lake on this warm summer afternoon. The combination of wind and boat waves provided a rough ride to the lower end of the lake. As I descended the rest of the lake, the concentration of Aphanizomenon flakes increased while other seston decreased substantially resulting in a marked improvement in water clarity.
Lake Pepin - "It lives in my memory as the Horicon of the wilderness. It is an extended portion of the Mississippi, - twenty-three miles long, and from three to four wide. It is surrounded with hills, which abound in almost every variety of game; its shores are gravelly and covered wit the most valuable of agates and cornelians; the water is clear, and very deep; and it yields the very best fish in great abundance."
"The lake is quite transparent, and yields several species of fish. The most remarkable of these is the acipenser spatularia (paddlefish), of which we obtained a specimen. It is also remarkable for its numerous varieties, and the large size of its fresh-water shells."
I reached Camp LuCapolis located at the bottom of the Lake Pepin on the Minnesota side at 5:39 p.m. I crossed over to the large sandy bank on the Wisconsin's shoreline in the Chippewa River delta to camp for the night. Water clarity improved dramatically as I proceeded to the opposite bank as a result of a marked decrease in colonial blue-green algae concentrations with transparency increasing to several feet. Beds of river pondweed were noted growing in relatively deep water at the lake's outlet along Wisconsin's main channel border and provided a sharp contrast to the algae laden waters of the opposite shoreline. I pitched my tent in the shade of small willow trees and quickly made dinner and followed it by a brief relaxing swim in the clear lake water. I was very tired and sore from the long day of canoeing and stayed up long enough to watch the sun set on Minnesota's bluffline. I thanked the Lord for the favorable winds and the successful ascent of this huge riverine lake and eagerly went to bed shortly after 8:30 p.m.
Praire Island Nuclear Generating Station in Lower Pool 3
Long Point - Lake Pepin