Problems
The environmental quality of Furman Lake and its environs has been declining
for several years, so as part of the “Year of the Environment” celebration,
a task force was established to study the lake, identify problems, and suggest
solutions. The task force identified four major problems with the lake:
- Populations of fecal-indicator bacteria were sometimes 50X higher than the upper EPA limit for
recreational waters.
- There were blooms of unsightly algae each summer.
- There were 362 resident waterfowl on the lake, including 250 Canada geese.
A lake this size should have a maximum of 50 waterfowl.
- The streams were carrying lots of sediment, and the sediment was deposited
in the lake. This fills the lake up, making it shallower and warmer.
The task force recommended a restoration plan that would improve the environmental
quality of the watershed, in an manner sensitive to the furman aesthetic, with
a focus on student engagement and learning.
The task force identified several contributors to these problems:
1. Nutrient loading from surface runoff:
Water running over land after rainfall or watering is called “surface
runoff”. This carries nutrients to the lakes and streams. Until 2007
the entire lakeshore was mown to the water line, and the banks of tributary
streams were mown or sprayed to remove stream-side vegetation (see photo). Water from precipitation
or sprinklers carried nutrients from mown, decaying vegetation, fertilizers,
and animal waste directly into the lake and tributary streams. Also, the conversion
of forest to lawns during the development of the Amphitheatre and the North
Village Dorm Complex, and the denuding of the North Village stream bank, probably
caused a dramatic increase in nutrient and sediment loading in that stream and
the lake.
2. Direct storm water discharge:
All of the parking areas and roadways in the lake’s watershed have storm
drains that empty directly into the lake or the two tributary streams. There
are also storm drains in the lawns that surround the lake, and these empty directly
into the lake, as well (photo). This storm water collected from
roads, parking lots, lawns, and rooftops contributes nutrients, pollutants, and sediments
to lakes and streams. These drains have been constructed in part because
using the lake as a stormwater retention facility has helped Furman earn LEED
points for new building construction. Retaining stormwater on site is certainly
an ecologically appropriate behavior. However, transferring it directly to the
lake and stream has probably had a dramatic negative effect on these habitats.
Storm drains allow water to bypass the normally slow transit through the soil
to the water table. Instead, water collected over huge areas is rapidly transferred
through drainpipes or channels. This huge volume of water, traveling quickly
under high pressure, erodes the lakeshore or stream bank at the point of entry,
and contributes nutrients and sediments to the lake and streams.
3. An overpopulation of waterfowl:
Large populations of waterfowl can contribute to the nutrient and bacterial
loading of lakes. Furman lake was home to a large population of resident
Canada Geese and domestic ducks. They were fed liberally by an adoring public,
but they fouled the water and lawns with their feces. On 3 July 2006, there were
362 waterfowl on 28-acre Furman Lake; six times the appropriate density for
a lake this size. Canada Geese harbor E. coli bacteria in their gut, and the
fouling of the lawns and lake with their feces was undoubtedly a major source
of E. coli contamination.
4. High water temperatures:
High water temperatures stimulate algal and bacterial growth (photo of algal mats, at right). At Furman Lake,
the lack of vegetation along the lakeshore probably contributed to unnecessarily
high water temperatures, especially because the lake is very shallow. Another potential source of heat loading is the stone retention wall
that surrounds approximately 50% of the lake. Heat absorbed in the afternoon
sun may transfer to the lake.
All of these factors probably contributed to the decline of the Furman
Lake environment. Unfortunately, many of the past decisions that Furman made in the
lake watershed increased the transport of sediment and nutrients to the
lake. Furman is now taking active steps to reduce and reverse these effects.