The Winooski River
stretches 90 miles from its headwaters in the town of Cabot
to its mouth just north of Burlington
yet its reach goes well beyond this winding line through the map. In fact the Winooski River
is part of the larger Winooski
River Basin or Basin 8 as
it has been effectively and
affectionately nicknamed by the Vermont Agency of Natural Resources. It drains
approximately 1,080 square miles or about 12 % of the state, exponentially
increasing the importance of this 90 mile meandering line through the map.
This line whose
significance is all too often lost upon the inhabitants along its banks, represents
the largest contributor freshwater into Lake Champlain but also the one of the largest
contributors of reactive phosphates and the largest contributor of dissolved
solids into Lake Champlain. The main reason
for the Winooski’s heavy pollutant load is it drains the largest watershed
entering the lake, but land usage in the watershed also has a strong effect on
the elements discharged into the lake.
A closer look at the land usage in the
Winooski River Watershed shows that while most of the land remains forested
(72.4 %) the second largest use by area is farming at 11.6 %. While this may at
first seem like a trivial amount, when you consider that the next most
prevalent land type in the watershed is open water at 4.7 % and that most of
this farm land lies directly alongside the river and it tributaries it begins
to become apparent just how large an effect farming has on the Winooski’s water
quality.
One of the major
pollutants arising from farming alongside the Winooski or any river for that
matter is dissolved solids coming from the erosion of banks once riparian
borders have been cut down to increase the arable land for farmers. This
phenomenon has been documented up and down the Winooski and is clearly visible
in many of the photos posted in the blog by our group. It is no wonder that the
Winooski contributes an estimated 140,000 tons of dissolved solids per year, or
about a third of the total dissolved solids loading in the lake each year.
The next major pollutant
coming from the Winooski
River is total phosphorous,
or in other words all the phosphate, phosphorous, and nitrates potentially available
to primary producers for nutrients. The Winooski River
is the third largest contributor of total phosphorous with a total of 270,146
lbs annually. The Winooski along with four other major rivers is responsible
for 58 % of the total load of phosphorous which enters the lake and annually,
meaning that these major rivers could potentially play a big role in the
reduction of total phosphorous introduction into Lake Champlain. Phosphates in
high concentrations like those seen in the Winooski River
generally come from fertilizers or animal waste spread by farmers but
residential fertilizers and septic pollution also play a role.
 |
| Fig. 1. Algae bloom in Lake Champlain |
The introduction of phosphorous into the
lake is of a particular concern because of the role it plays in the eutrophication
of lakes. In Lake Champlain the lake can be divided into several water masses
or “basins” and according to Henson and Potash in the 1976 study Materials Budgets of Lake Champlain the
“a number of the peripheral embayments are showing indications of eutrophication.”
This is of real concern in Lake Champlain
where more recently toxic algal blooms and excessive aquatic plant growth have
become real issues in some of the shallower basins (see Fig. 1.)
There is however hope for the waters of the Winooski and the greater Lake Champlain which they feed. With the help of the Clean Water Act and public support, organizations like the Vermont River Conservancy and the Vermont Natural Resources Council are working to repair riparian borders, enforce existing water quality standards, and create new policies aimed at strengthening regulations and creating incentive programs for protecting rivers.
Sources:
Materials budgets of Lake Champlain : a
completion report to the Department of Interior, Office of
Water Resources and Technology. E. B. Henson, Milton
Potash. Burlington : Dept. of Zoology,
University of Vermont, 1976. In Print.
The Vermont River Conservancy
Vermont Natural Resources Council
Recent Evidence of Eutrophication in Lake Champlain
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