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This entire nearly level basin (some 80 acres) was once filled with
peat. It is bounded on the west and north by University Bay Drive,
and on the southeast by the Natatorium and Marsh Creek. On the
south it once graded up into prairies and fields about where Marsh
Lane is now.
Peat accumulates where waterlogging prevents access of oxygen so
that bacteria cannot feed on plant remains. Kept wet by runoff and
springs, the basin had been a soggy area for over 10,000 years,
although it was sometimes above the level of Lake Mendota. As the
last glacier retreated, damming the Yahara Valley with deposits of
mud and gravel, this basin was probably a bay of the lake at a
high-level stage. Study may show that the first peat to be laid down
was of sphagnum and wiregrass sedge, containing pollen of spruce and
fir; for most of our peat deposits began as floating bogs like those
of bays in our present northern lakes.
The lake may have backed up to higher levels at more recent times
because of dense vegetation and beaver dams at the outlet; but
around the turn of the century, it was getting lower because of
erosion of the outlet. This basin was probably a sedge meadow then.
In 1912, the Tenney Park Locks were installed, raising the lake
above the level of this peaty basin.
To put the peat meadow to use, a leaf was taken from the thrifty
Dutch: tile the fields, build a dike and use a pump. The filled
dike, built on an ice-push-up-ridge, became University Bay Drive;
the faithful pump in the metal shed nearby continually removed
seepage coming from the peaty field and from the lake for over 50
years. A sign on the pumphouse explained this pilot land reclamation
project. With proper fertilizer, the peat field yielded excellent
crops of corn. Unfortunately, not all lowlands had a lake to protect
them from summer frost damage; so following the University's advice
to drain and farm the lowlands did not always meet with such success
elsewhere.
Farming had increased wildlife abundance because the field provided
abundant food - both waste corn and the weeds perpetuated by soil
disturbance. Shorebirds, ducks and geese that circled the lake would
drop in at the field in spectacular numbers. The adjacent and slowly
encroaching weedy University Dump (now Lot 60) and the marshy
ditches helped also, and together they attracted bird watchers from
far and wide to see rarities like pipits, snow buntings, snow and
blue geese, phalaropes, white crowned and Harris' sparrows, and
short-eared owls. Pheasants thrived on the corn also.
Wildlife use intensified in 1967 when progressive oxidation of the
drained peat deposit had finally caused the deeply-laid drain tiles
to appear on the surface, interfering with plowing and harvesting
machinery. The pump was turned off, and the flooded ripening crop of
corn was soon discovered by all of Madison's mallards and teal,
which began commuting daily over the city. One could stand at Lot 60
and see hundreds of mallards descend from the sky at sunset. Still
more migrating waterfowl came in from the lake that fall, and in the
spring of 1968, many water birds stayed to nest as the 30-acre
flooded field began to provide water plants for cover. This became
the spot to see, with ease, beauties like green-winged teal, ruddy
and shoveller ducks, and the elusive gallinules and rails of the
deep water marsh.
Argument arose over the use of the land, which was avidly sought for
parking space and athletic fields, as well as for wildlife habitat
accessible to biology classes and nature-lovers. The present
compromise divides this land between these three uses. To some
extent they overlap, since parking makes the area accessible to more
wildlife viewers for recreation, and the playing fields, when not in
use, provide quiet buffering open space around the present small
marsh for the flying, feeding and roosting needs of birds.
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